Merge remote-tracking branch 'upstream/master' into poll

2020-01-16 13:06:02 +01:00
parent d31242c2e2 adcc047f4a
commit cea6542fd8
52 changed files with 1200 additions and 447 deletions
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -71,7 +71,7 @@ jobs:
    - uses: ./.github/actions/install-rust
      with:
        toolchain: nightly
-    - run: cargo install cargo-fuzz --vers "^0.6"
+    - run: cargo install cargo-fuzz --vers "^0.7"
    - run: cargo fetch
      working-directory: ./fuzz
    - run: cargo fuzz build --release --debug-assertions
@@ -165,6 +165,7 @@ jobs:
    - run: rustup target add wasm32-wasi

    - run: cargo fetch --locked
+    - run: cargo fetch --locked --manifest-path crates/test-programs/wasi-tests/Cargo.toml

    # Build and test all features except for lightbeam
    - run: cargo test --features test_programs --all --exclude lightbeam -- --nocapture
@@ -302,7 +303,7 @@ jobs:
    - run: $CENTOS cargo build --release --bin wasmtime --bin wasm2obj
      shell: bash
    # Build `libwasmtime.so`
-    - run: $CENTOS cargo build --release --manifest-path crates/api/Cargo.toml
+    - run: $CENTOS cargo build --release --manifest-path crates/c-api/Cargo.toml
      shell: bash
    # Test what we just built
    - run: $CENTOS cargo test --features test_programs --release --all --exclude lightbeam --exclude wasmtime --exclude wasmtime-fuzzing
@@ -511,4 +512,3 @@ jobs:
        files: "dist/*"
        name: ${{ steps.tagname.outputs.val }}
        token: ${{ secrets.GITHUB_TOKEN }}
-
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,8 +1,8 @@
 [submodule "spec_testsuite"]
 	path = tests/spec_testsuite
 	url = https://github.com/WebAssembly/testsuite
-[submodule "crates/api/c-examples/wasm-c-api"]
-	path = crates/api/c-examples/wasm-c-api
+[submodule "crates/c-api/examples/wasm-c-api"]
+	path = crates/c-api/examples/wasm-c-api
 	url = https://github.com/WebAssembly/wasm-c-api
 [submodule "crates/wasi-common/WASI"]
 	path = crates/wasi-common/wig/WASI
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -30,6 +30,15 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "64cf76cb6e2222ed0ea86b2b0ee2f71c96ec6edd5af42e84d59160e91b836ec4"

+[[package]]
+name = "arbitrary"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b93b22576af8f14bb2bad6a5dc09c4f80539a801f7ea340c798e222f2ce49859"
+dependencies = [
+ "derive_arbitrary",
+]
+
 [[package]]
 name = "arrayref"
 version = "0.3.5"
@@ -76,9 +85,9 @@ checksum = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"

 [[package]]
 name = "backtrace"
-version = "0.3.40"
+version = "0.3.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "924c76597f0d9ca25d762c25a4d369d51267536465dc5064bdf0eb073ed477ea"
+checksum = "b4b1549d804b6c73f4817df2ba073709e96e426f12987127c48e6745568c350b"
 dependencies = [
 "backtrace-sys",
 "cfg-if",
@@ -159,8 +168,8 @@ dependencies = [
 "lazycell",
 "log",
 "peeking_take_while",
- "proc-macro2",
- "quote",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
 "regex",
 "rustc-hash",
 "shlex",
@@ -341,24 +350,25 @@ dependencies = [

 [[package]]
 name = "cranelift-bforest"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bd3225fff1be118941c5fb66f1fb1f7f3e86468fac0e7364713c4fb99b72632b"
+checksum = "40af6e6f7419110906d0f7b4b8084d3216be64d7da77aa12887885ebe0fc2776"
 dependencies = [
 "cranelift-entity",
 ]

 [[package]]
 name = "cranelift-codegen"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3e3e6679892029f76a99b9059d2b74e77ac03637d573bb014bc21579ec1b7da"
+checksum = "88583eb22e5cd0fe1ef66f0b80d0063d21d30e84e887d08b3d369def3ea7b4be"
 dependencies = [
 "byteorder",
 "cranelift-bforest",
 "cranelift-codegen-meta",
 "cranelift-codegen-shared",
 "cranelift-entity",
+ "gimli",
 "log",
 "serde",
 "smallvec",
@@ -368,9 +378,9 @@ dependencies = [

 [[package]]
 name = "cranelift-codegen-meta"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3cabe691548e28ca82ebd218f2fe76eec4c5629b64ef3db8b58443b7d9047275"
+checksum = "353872c984943b9134d7c835eb9d12932bd90f4992dbe666593771bee920d673"
 dependencies = [
 "cranelift-codegen-shared",
 "cranelift-entity",
@@ -378,24 +388,24 @@ dependencies = [

 [[package]]
 name = "cranelift-codegen-shared"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d173252ffade4aa6e929090977b9a4cd5ac28e15a42626f878be3844b3000ad9"
+checksum = "cd1e96479a56981cce5c8f14d26773195d662ccdbbeca39fb8eba22b5ca8ea6a"

 [[package]]
 name = "cranelift-entity"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3498ad9ba021715716a1c52e2b31d7829a149913fb0d88493e4b07d3b772b656"
+checksum = "37bc8dc3d4274ededc687d84821f491a8a03447dbb7481983936220892cf55b4"
 dependencies = [
 "serde",
 ]

 [[package]]
 name = "cranelift-frontend"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "521a30773b8de74345c807a38853f055aca8fecaa39a0fc7698bfebc5a3da515"
+checksum = "4ea33e55bda8c425f3f533355b03e3a43cf29b4e228b35b868b6a1c43b6a139e"
 dependencies = [
 "cranelift-codegen",
 "log",
@@ -405,9 +415,9 @@ dependencies = [

 [[package]]
 name = "cranelift-native"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "624e755cbe984e437308968239736e7f9aa3193e99928fb76eec7a1946627b34"
+checksum = "2c22cfaaa5e69eddaddd6cfa7a76233de964b9b2245e81a5f47dae739931ad0d"
 dependencies = [
 "cranelift-codegen",
 "raw-cpuid",
@@ -416,9 +426,9 @@ dependencies = [

 [[package]]
 name = "cranelift-wasm"
-version = "0.54.0"
+version = "0.55.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0320733e518ab9e0e2d1a22034d40e2851fb403ed14db5220cf9b86576b9cfd4"
+checksum = "038f8fd636abc83ccd6f110e0891766521c3599b52173c0f37e61c684f19a15d"
 dependencies = [
 "cranelift-codegen",
 "cranelift-entity",
@@ -426,7 +436,7 @@ dependencies = [
 "log",
 "serde",
 "thiserror",
- "wasmparser 0.45.2",
+ "wasmparser 0.47.0",
 ]

 [[package]]
@@ -513,8 +523,8 @@ version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd8ce37ad4184ab2ce004c33bf6379185d3b1c95801cab51026bd271bf68eedc"
 dependencies = [
- "quote",
- "syn",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -526,6 +536,17 @@ dependencies = [
 "cfg-if",
 ]

+[[package]]
+name = "derive_arbitrary"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b979a9f98d526ac07489ae2879e04d948ceeb195d777742997a30c3d1ab1aad6"
+dependencies = [
+ "proc-macro2 0.4.30",
+ "syn 0.14.9",
+ "synstructure 0.9.0",
+]
+
 [[package]]
 name = "digest"
 version = "0.8.1"
@@ -567,9 +588,9 @@ dependencies = [
 "byteorder",
 "lazy_static",
 "owning_ref",
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -667,10 +688,10 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bc225b78e0391e4b8683440bf2e63c2deeeb2ce5189eab46e2b68c6d3725d08"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
- "synstructure",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
+ "synstructure 0.12.3",
 ]

 [[package]]
@@ -745,9 +766,9 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a36606a68532b5640dc86bb1f33c64b45c4682aad4c50f3937b317ea387f3d6"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -839,9 +860,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b714fc08d0961716390977cdff1536234415ac37b509e34e5a983def8340fb75"
 dependencies = [
 "proc-macro-hack",
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 "unindent",
 ]

@@ -862,9 +883,9 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0a8e30575afe28eea36a9a39136b70b2fb6b0dd0a212a5bd1f30a498395c0274"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -917,10 +938,11 @@ checksum = "d515b1f41455adea1313a4a2ac8a8a477634fbae63cc6100e3aebb207ce61558"

 [[package]]
 name = "libfuzzer-sys"
-version = "0.1.0"
-source = "git+https://github.com/rust-fuzz/libfuzzer-sys.git#0c4507533a79e85e1984f59765bdd35fbdaa7f1b"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94f9e4f036a9cb9f43c637990c03fe045425a33c1c44abf9bc6f555671be5969"
 dependencies = [
- "arbitrary",
+ "arbitrary 0.3.2",
 "cc",
 ]

@@ -1144,9 +1166,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4214c9e912ef61bf42b81ba9a47e8aad1b2ffaf739ab162bf96d1e011f54e6c5"
 dependencies = [
 "proc-macro-hack",
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1185,10 +1207,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "53c98547ceaea14eeb26fcadf51dc70d01a2479a7839170eae133721105e4428"
 dependencies = [
 "proc-macro-error-attr",
- "proc-macro2",
- "quote",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
 "rustversion",
- "syn",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1197,10 +1219,10 @@ version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2bf5d493cf5d3e296beccfd61794e445e830dfc8070a9c248ad3ee071392c6c"
 dependencies = [
- "proc-macro2",
- "quote",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
 "rustversion",
- "syn",
+ "syn 1.0.13",
 "syn-mid",
 ]

@@ -1210,9 +1232,18 @@ version = "0.5.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ecd45702f76d6d3c75a80564378ae228a85f0b59d2f3ed43c91b4a69eb2ebfc5"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "0.4.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
+dependencies = [
+ "unicode-xid 0.1.0",
 ]

 [[package]]
@@ -1221,7 +1252,7 @@ version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0319972dcae462681daf4da1adeeaa066e3ebd29c69be96c6abb1259d2ee2bcc"
 dependencies = [
- "unicode-xid",
+ "unicode-xid 0.2.0",
 ]

 [[package]]
@@ -1251,9 +1282,9 @@ version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4882d8237fd8c7373cc25cb802fe0dab9ff70830fd56f47ef6c7f3f287fcc057"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1262,10 +1293,10 @@ version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdf321cfab555f7411298733c86d21e5136f5ded13f5872fabf9de3337beecda"
 dependencies = [
- "proc-macro2",
+ "proc-macro2 1.0.7",
 "pyo3-derive-backend",
- "quote",
- "syn",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1286,13 +1317,22 @@ dependencies = [
 "rand_core 0.5.1",
 ]

+[[package]]
+name = "quote"
+version = "0.6.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ce23b6b870e8f94f81fb0a363d65d86675884b34a09043c81e5562f11c1f8e1"
+dependencies = [
+ "proc-macro2 0.4.30",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
 dependencies = [
- "proc-macro2",
+ "proc-macro2 1.0.7",
 ]

 [[package]]
@@ -1517,9 +1557,9 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3a0538bd897e17257b0128d2fd95c2ed6df939374073a36166051a79e2eb7986"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1549,9 +1589,9 @@ version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8584eea9b9ff42825b46faf46a8c24d2cff13ec152fa2a50df788b87c07ee28"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1584,9 +1624,9 @@ version = "1.0.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "128f9e303a5a29922045a830221b8f78ec74a5f544944f3d5984f8ec3895ef64"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1669,9 +1709,20 @@ checksum = "0a97f829a34a0a9d5b353a881025a23b8c9fd09d46be6045df6b22920dbd7a93"
 dependencies = [
 "heck",
 "proc-macro-error",
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
+]
+
+[[package]]
+name = "syn"
+version = "0.14.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "261ae9ecaa397c42b960649561949d69311f08eeaea86a65696e6e46517cf741"
+dependencies = [
+ "proc-macro2 0.4.30",
+ "quote 0.6.13",
+ "unicode-xid 0.1.0",
 ]

 [[package]]
@@ -1680,9 +1731,9 @@ version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e4ff033220a41d1a57d8125eab57bf5263783dfdcc18688b1dacc6ce9651ef8"
 dependencies = [
- "proc-macro2",
- "quote",
- "unicode-xid",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "unicode-xid 0.2.0",
 ]

 [[package]]
@@ -1691,9 +1742,21 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9fd3937748a7eccff61ba5b90af1a20dbf610858923a9192ea0ecb0cb77db1d0"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
+]
+
+[[package]]
+name = "synstructure"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85bb9b7550d063ea184027c9b8c20ac167cd36d3e06b3a40bceb9d746dc1a7b7"
+dependencies = [
+ "proc-macro2 0.4.30",
+ "quote 0.6.13",
+ "syn 0.14.9",
+ "unicode-xid 0.1.0",
 ]

 [[package]]
@@ -1702,10 +1765,10 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "67656ea1dc1b41b1451851562ea232ec2e5a80242139f7e679ceccfb5d61f545"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
- "unicode-xid",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
+ "unicode-xid 0.2.0",
 ]

 [[package]]
@@ -1780,9 +1843,9 @@ version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eb2e25d25307eb8436894f727aba8f65d07adf02e5b35a13cebed48bd282bfef"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1861,6 +1924,12 @@ version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "caaa9d531767d1ff2150b9332433f32a24622147e5ebb1f26409d5da67afd479"

+[[package]]
+name = "unicode-xid"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.0"
@@ -1921,9 +1990,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8757b0da38353d55a9687f4dee68a8f441f980dd36e16ab07d6e6c673f505f76"
 dependencies = [
 "heck",
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -1958,9 +2027,9 @@ dependencies = [
 name = "wasi-common-cbindgen"
 version = "0.9.0"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 "trybuild",
 ]

@@ -1988,12 +2057,6 @@ version = "0.42.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1527c84a5bd585215f29c06b0e2a5274e478ad4dfc970d26ffad66fdc6cb311d"

-[[package]]
-name = "wasmparser"
-version = "0.45.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b4eab1d9971d0803729cba3617b56eb04fcb4bd25361cb63880ed41a42f20d5"
-
 [[package]]
 name = "wasmparser"
 version = "0.47.0"
@@ -2015,6 +2078,7 @@ name = "wasmtime"
 version = "0.9.0"
 dependencies = [
 "anyhow",
+ "backtrace",
 "cfg-if",
 "file-per-thread-logger",
 "libc",
@@ -2031,6 +2095,13 @@ dependencies = [
 "winapi",
 ]

+[[package]]
+name = "wasmtime-c-api"
+version = "0.9.0"
+dependencies = [
+ "wasmtime",
+]
+
 [[package]]
 name = "wasmtime-cli"
 version = "0.9.0"
@@ -2113,7 +2184,7 @@ dependencies = [
 name = "wasmtime-fuzz"
 version = "0.9.0"
 dependencies = [
- "arbitrary",
+ "arbitrary 0.2.0",
 "env_logger 0.7.1",
 "libfuzzer-sys",
 "log",
@@ -2127,7 +2198,7 @@ name = "wasmtime-fuzzing"
 version = "0.9.0"
 dependencies = [
 "anyhow",
- "arbitrary",
+ "arbitrary 0.3.2",
 "binaryen",
 "env_logger 0.7.1",
 "log",
@@ -2205,6 +2276,7 @@ dependencies = [
 name = "wasmtime-runtime"
 version = "0.9.0"
 dependencies = [
+ "backtrace",
 "cc",
 "cfg-if",
 "indexmap",
@@ -2233,9 +2305,9 @@ dependencies = [
 name = "wasmtime-rust-macro"
 version = "0.9.0"
 dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
+ "syn 1.0.13",
 ]

 [[package]]
@@ -2323,8 +2395,8 @@ name = "wig"
 version = "0.9.2"
 dependencies = [
 "heck",
- "proc-macro2",
- "quote",
+ "proc-macro2 1.0.7",
+ "quote 1.0.2",
 "witx",
 ]

--- a/Cargo.toml
+++ b/Cargo.toml
@@ -55,6 +55,7 @@ members = [
  "crates/fuzzing",
  "crates/misc/rust",
  "crates/misc/py",
+  "crates/c-api",
  "fuzz",
 ]

--- a/ci/build-tarballs.sh
+++ b/ci/build-tarballs.sh
@@ -48,7 +48,7 @@ mkdir tmp/$api_pkgname/lib
 mkdir tmp/$api_pkgname/include
 cp LICENSE README.md tmp/$api_pkgname
 mv bins-$src/* tmp/$api_pkgname/lib
-cp crates/api/c-examples/wasm-c-api/include/wasm.h tmp/$api_pkgname/include
+cp crates/c-api/examples/wasm-c-api/include/wasm.h tmp/$api_pkgname/include
 mktarball $api_pkgname

 # Move wheels to dist folder
--- a/crates/api/Cargo.toml
+++ b/crates/api/Cargo.toml
@@ -8,10 +8,6 @@ repository = "https://github.com/bytecodealliance/wasmtime"
 readme = "README.md"
 edition = "2018"

-[lib]
-name = "wasmtime"
-crate-type = ["lib", "staticlib", "cdylib"]
-
 [dependencies]
 wasmtime-runtime = { path = "../runtime", version = "0.9.0" }
 wasmtime-environ = { path = "../environ", version = "0.9.0" }
@@ -22,6 +18,7 @@ anyhow = "1.0.19"
 region = "2.0.0"
 libc = "0.2"
 cfg-if = "0.1.9"
+backtrace = "0.3.42"

 [target.'cfg(target_os = "windows")'.dependencies]
 winapi = "0.3.7"
--- a/crates/api/README.md
+++ b/crates/api/README.md
@@ -1,3 +1,8 @@
-# Implementation of wasm-c-api in Rust
+## Wasmtime Embedding API

-https://github.com/WebAssembly/wasm-c-api
+The `wasmtime` crate is an embedding API of the `wasmtime` WebAssembly runtime.
+This is intended to be used in Rust projects and provides a high-level API of
+working with WebAssembly modules.
+
+If you're interested in embedding `wasmtime` in other languages, you may wish to
+take a look a the [C embedding API](../c-api) instead!
--- a/crates/api/src/callable.rs
+++ b/crates/api/src/callable.rs
@@ -141,13 +141,12 @@ impl WrappedCallable for WasmtimeFn {
        // Get the trampoline to call for this function.
        let exec_code_buf = self
            .store
-            .context()
-            .compiler()
+            .compiler_mut()
            .get_published_trampoline(body, &signature, value_size)
            .map_err(|e| Trap::new(format!("trampoline error: {:?}", e)))?;

        // Call the trampoline.
-        if let Err(message) = unsafe {
+        if let Err(error) = unsafe {
            self.instance.with_signals_on(|| {
                wasmtime_runtime::wasmtime_call_trampoline(
                    vmctx,
@@ -156,8 +155,7 @@ impl WrappedCallable for WasmtimeFn {
                )
            })
        } {
-            let trap =
-                take_api_trap().unwrap_or_else(|| Trap::new(format!("call error: {}", message)));
+            let trap = take_api_trap().unwrap_or_else(|| Trap::from_jit(error));
            return Err(trap);
        }

--- a/crates/api/src/context.rs
+++ b/crates/api/src/context.rs
@@ -1,53 +0,0 @@
-use crate::Config;
-use std::cell::{RefCell, RefMut};
-use std::hash::{Hash, Hasher};
-use std::rc::Rc;
-use wasmtime_environ::settings;
-use wasmtime_jit::{native, Compiler, Features};
-
-#[derive(Clone)]
-pub struct Context {
-    compiler: Rc<RefCell<Compiler>>,
-    features: Features,
-    debug_info: bool,
-}
-
-impl Context {
-    pub fn new(config: &Config) -> Context {
-        let isa = native::builder().finish(settings::Flags::new(config.flags.clone()));
-        Context::new_with_compiler(config, Compiler::new(isa, config.strategy))
-    }
-
-    pub fn new_with_compiler(config: &Config, compiler: Compiler) -> Context {
-        Context {
-            compiler: Rc::new(RefCell::new(compiler)),
-            features: config.features.clone(),
-            debug_info: config.debug_info,
-        }
-    }
-
-    pub(crate) fn debug_info(&self) -> bool {
-        self.debug_info
-    }
-
-    pub(crate) fn compiler(&self) -> RefMut<Compiler> {
-        self.compiler.borrow_mut()
-    }
-}
-
-impl Hash for Context {
-    fn hash<H>(&self, state: &mut H)
-    where
-        H: Hasher,
-    {
-        self.compiler.as_ptr().hash(state)
-    }
-}
-
-impl Eq for Context {}
-
-impl PartialEq for Context {
-    fn eq(&self, other: &Context) -> bool {
-        Rc::ptr_eq(&self.compiler, &other.compiler)
-    }
-}
--- a/crates/api/src/instance.rs
+++ b/crates/api/src/instance.rs
@@ -1,4 +1,3 @@
-use crate::context::Context;
 use crate::externals::Extern;
 use crate::module::Module;
 use crate::runtime::Store;
@@ -6,9 +5,6 @@ use crate::trampoline::take_api_trap;
 use crate::trap::Trap;
 use crate::types::{ExportType, ExternType};
 use anyhow::{Error, Result};
-use std::cell::RefCell;
-use std::collections::{HashMap, HashSet};
-use std::rc::Rc;
 use wasmtime_jit::{CompiledModule, Resolver};
 use wasmtime_runtime::{Export, InstanceHandle, InstantiationError};

@@ -29,19 +25,15 @@ fn instantiate_in_context(
    data: &[u8],
    imports: &[Extern],
    module_name: Option<&str>,
-    context: Context,
-    exports: Rc<RefCell<HashMap<String, Option<wasmtime_runtime::Export>>>>,
-) -> Result<(InstanceHandle, HashSet<Context>), Error> {
-    let mut contexts = HashSet::new();
-    let debug_info = context.debug_info();
+) -> Result<InstanceHandle> {
    let mut resolver = SimpleResolver { imports };
    let mut compiled_module = CompiledModule::new(
-        &mut context.compiler(),
+        &mut store.compiler_mut(),
        data,
        module_name,
        &mut resolver,
-        exports,
-        debug_info,
+        store.global_exports().clone(),
+        store.engine().config().debug_info,
    )?;

    // Register all module signatures
@@ -52,40 +44,30 @@ fn instantiate_in_context(
    let instance = compiled_module.instantiate().map_err(|e| -> Error {
        if let Some(trap) = take_api_trap() {
            trap.into()
-        } else if let InstantiationError::StartTrap(msg) = e {
-            Trap::new(msg).into()
+        } else if let InstantiationError::StartTrap(trap) = e {
+            Trap::from_jit(trap).into()
        } else {
            e.into()
        }
    })?;
-    contexts.insert(context);
-    Ok((instance, contexts))
+    Ok(instance)
 }

 #[derive(Clone)]
 pub struct Instance {
    instance_handle: InstanceHandle,
-
    module: Module,
-
-    // We need to keep CodeMemory alive.
-    contexts: HashSet<Context>,
-
    exports: Box<[Extern]>,
 }

 impl Instance {
    pub fn new(module: &Module, externs: &[Extern]) -> Result<Instance, Error> {
        let store = module.store();
-        let context = store.context().clone();
-        let exports = store.global_exports().clone();
-        let (mut instance_handle, contexts) = instantiate_in_context(
-            module.store(),
+        let mut instance_handle = instantiate_in_context(
+            store,
            module.binary().expect("binary"),
            externs,
            module.name(),
-            context,
-            exports,
        )?;

        let exports = {
@@ -104,7 +86,6 @@ impl Instance {
        Ok(Instance {
            instance_handle,
            module: module.clone(),
-            contexts,
            exports,
        })
    }
@@ -141,8 +122,6 @@ impl Instance {
    }

    pub fn from_handle(store: &Store, instance_handle: InstanceHandle) -> Instance {
-        let contexts = HashSet::new();
-
        let mut exports = Vec::new();
        let mut exports_types = Vec::new();
        let mut mutable = instance_handle.clone();
@@ -175,7 +154,6 @@ impl Instance {
        Instance {
            instance_handle,
            module,
-            contexts,
            exports: exports.into_boxed_slice(),
        }
    }
--- a/crates/api/src/lib.rs
+++ b/crates/api/src/lib.rs
@@ -7,7 +7,6 @@
 //! itself for consumption from other languages.

 mod callable;
-mod context;
 mod externals;
 mod instance;
 mod module;
@@ -18,13 +17,11 @@ mod trap;
 mod types;
 mod values;

-pub mod wasm;
-
 pub use crate::callable::Callable;
 pub use crate::externals::*;
 pub use crate::instance::Instance;
 pub use crate::module::Module;
-pub use crate::r#ref::AnyRef;
+pub use crate::r#ref::{AnyRef, HostInfo, HostRef};
 pub use crate::runtime::{Config, Engine, OptLevel, Store, Strategy};
 pub use crate::trap::{FrameInfo, Trap};
 pub use crate::types::*;
--- a/crates/api/src/module.rs
+++ b/crates/api/src/module.rs
@@ -196,7 +196,7 @@ impl Module {
    ///
    /// [binary]: https://webassembly.github.io/spec/core/binary/index.html
    pub fn validate(store: &Store, binary: &[u8]) -> Result<()> {
-        let features = store.engine().config.features.clone();
+        let features = store.engine().config().features.clone();
        let config = ValidatingParserConfig {
            operator_config: OperatorValidatorConfig {
                enable_threads: features.threads,
--- a/crates/api/src/runtime.rs
+++ b/crates/api/src/runtime.rs
@@ -1,4 +1,3 @@
-use crate::context::Context;
 use anyhow::Result;
 use std::cell::RefCell;
 use std::collections::HashMap;
@@ -8,7 +7,7 @@ use wasmtime_environ::{
    ir,
    settings::{self, Configurable},
 };
-use wasmtime_jit::{CompilationStrategy, Features};
+use wasmtime_jit::{native, CompilationStrategy, Compiler, Features};

 // Runtime Environment

@@ -297,7 +296,7 @@ pub enum OptLevel {
 /// default settings.
 #[derive(Default, Clone)]
 pub struct Engine {
-    pub(crate) config: Arc<Config>,
+    config: Arc<Config>,
 }

 impl Engine {
@@ -308,6 +307,11 @@ impl Engine {
            config: Arc::new(config.clone()),
        }
    }
+
+    /// Returns the configuration settings that this engine is using.
+    pub fn config(&self) -> &Config {
+        &self.config
+    }
 }

 // Store
@@ -337,7 +341,7 @@ pub struct Store {

 struct StoreInner {
    engine: Engine,
-    context: Context,
+    compiler: RefCell<Compiler>,
    global_exports: Rc<RefCell<HashMap<String, Option<wasmtime_runtime::Export>>>>,
    signature_cache: RefCell<HashMap<wasmtime_runtime::VMSharedSignatureIndex, ir::Signature>>,
 }
@@ -345,10 +349,12 @@ struct StoreInner {
 impl Store {
    /// Creates a new store to be associated with the given [`Engine`].
    pub fn new(engine: &Engine) -> Store {
+        let isa = native::builder().finish(settings::Flags::new(engine.config.flags.clone()));
+        let compiler = Compiler::new(isa, engine.config.strategy);
        Store {
            inner: Rc::new(StoreInner {
                engine: engine.clone(),
-                context: Context::new(&engine.config),
+                compiler: RefCell::new(compiler),
                global_exports: Rc::new(RefCell::new(HashMap::new())),
                signature_cache: RefCell::new(HashMap::new()),
            }),
@@ -360,8 +366,8 @@ impl Store {
        &self.inner.engine
    }

-    pub(crate) fn context(&self) -> &Context {
-        &self.inner.context
+    pub(crate) fn compiler_mut(&self) -> std::cell::RefMut<'_, Compiler> {
+        self.inner.compiler.borrow_mut()
    }

    // Specific to wasmtime: hack to pass memory around to wasi
@@ -377,7 +383,7 @@ impl Store {
        signature: &ir::Signature,
    ) -> wasmtime_runtime::VMSharedSignatureIndex {
        use std::collections::hash_map::Entry;
-        let index = self.context().compiler().signatures().register(signature);
+        let index = self.compiler_mut().signatures().register(signature);
        match self.inner.signature_cache.borrow_mut().entry(index) {
            Entry::Vacant(v) => {
                v.insert(signature.clone());
@@ -398,7 +404,13 @@ impl Store {
            .cloned()
    }

-    pub(crate) fn ptr_eq(a: &Store, b: &Store) -> bool {
+    /// Returns whether the stores `a` and `b` refer to the same underlying
+    /// `Store`.
+    ///
+    /// Because the `Store` type is reference counted multiple clones may point
+    /// to the same underlying storage, and this method can be used to determine
+    /// whether two stores are indeed the same.
+    pub fn same(a: &Store, b: &Store) -> bool {
        Rc::ptr_eq(&a.inner, &b.inner)
    }
 }
--- a/crates/api/src/trampoline/func.rs
+++ b/crates/api/src/trampoline/func.rs
@@ -11,7 +11,9 @@ use wasmtime_environ::entity::{EntityRef, PrimaryMap};
 use wasmtime_environ::ir::types;
 use wasmtime_environ::isa::TargetIsa;
 use wasmtime_environ::wasm::{DefinedFuncIndex, FuncIndex};
-use wasmtime_environ::{ir, settings, CompiledFunction, Export, Module, TrapInformation};
+use wasmtime_environ::{
+    ir, settings, CompiledFunction, CompiledFunctionUnwindInfo, Export, Module, TrapInformation,
+};
 use wasmtime_jit::trampoline::ir::{
    ExternalName, Function, InstBuilder, MemFlags, StackSlotData, StackSlotKind,
 };
@@ -136,6 +138,7 @@ fn make_trampoline(

    let mut context = Context::new();
    context.func = Function::with_name_signature(ExternalName::user(0, 0), signature.clone());
+    context.func.collect_frame_layout_info();

    let ss = context.func.create_stack_slot(StackSlotData::new(
        StackSlotKind::ExplicitSlot,
@@ -213,8 +216,7 @@ fn make_trampoline(
        .map_err(|error| pretty_error(&context.func, Some(isa), error))
        .expect("compile_and_emit");

-    let mut unwind_info = Vec::new();
-    context.emit_unwind_info(isa, &mut unwind_info);
+    let unwind_info = CompiledFunctionUnwindInfo::new(isa, &context);

    let traps = trap_sink.traps;

--- a/crates/api/src/trap.rs
+++ b/crates/api/src/trap.rs
@@ -1,4 +1,5 @@
 use crate::instance::Instance;
+use backtrace::Backtrace;
 use std::fmt;
 use std::sync::Arc;

@@ -11,7 +12,8 @@ pub struct Trap {

 struct TrapInner {
    message: String,
-    trace: Vec<FrameInfo>,
+    wasm_trace: Vec<FrameInfo>,
+    native_trace: Backtrace,
 }

 fn _assert_trap_is_sync_and_send(t: &Trap) -> (&dyn Sync, &dyn Send) {
@@ -26,10 +28,29 @@ impl Trap {
    /// assert_eq!("unexpected error", trap.message());
    /// ```
    pub fn new<I: Into<String>>(message: I) -> Self {
+        Trap::new_with_trace(message.into(), Backtrace::new_unresolved())
+    }
+
+    pub(crate) fn from_jit(jit: wasmtime_runtime::Trap) -> Self {
+        Trap::new_with_trace(jit.to_string(), jit.backtrace)
+    }
+
+    fn new_with_trace(message: String, native_trace: Backtrace) -> Self {
+        let mut wasm_trace = Vec::new();
+        for frame in native_trace.frames() {
+            let pc = frame.ip() as usize;
+            if let Some(info) = wasmtime_runtime::jit_function_registry::find(pc) {
+                wasm_trace.push(FrameInfo {
+                    func_index: info.func_index as u32,
+                    module_name: info.module_id.clone(),
+                })
+            }
+        }
        Trap {
            inner: Arc::new(TrapInner {
-                message: message.into(),
-                trace: Vec::new(),
+                message,
+                wasm_trace,
+                native_trace,
            }),
        }
    }
@@ -40,7 +61,7 @@ impl Trap {
    }

    pub fn trace(&self) -> &[FrameInfo] {
-        &self.inner.trace
+        &self.inner.wasm_trace
    }
 }

@@ -48,7 +69,8 @@ impl fmt::Debug for Trap {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Trap")
            .field("message", &self.inner.message)
-            .field("trace", &self.inner.trace)
+            .field("wasm_trace", &self.inner.wasm_trace)
+            .field("native_trace", &self.inner.native_trace)
            .finish()
    }
 }
@@ -62,22 +84,29 @@ impl fmt::Display for Trap {
 impl std::error::Error for Trap {}

 #[derive(Debug)]
-pub struct FrameInfo;
+pub struct FrameInfo {
+    module_name: Option<String>,
+    func_index: u32,
+}

 impl FrameInfo {
    pub fn instance(&self) -> *const Instance {
        unimplemented!("FrameInfo::instance");
    }

-    pub fn func_index() -> usize {
-        unimplemented!("FrameInfo::func_index");
+    pub fn func_index(&self) -> u32 {
+        self.func_index
    }

-    pub fn func_offset() -> usize {
+    pub fn func_offset(&self) -> usize {
        unimplemented!("FrameInfo::func_offset");
    }

-    pub fn module_offset() -> usize {
+    pub fn module_offset(&self) -> usize {
        unimplemented!("FrameInfo::module_offset");
    }
+
+    pub fn module_name(&self) -> Option<&str> {
+        self.module_name.as_deref()
+    }
 }
--- a/crates/api/tests/invoke_func_via_table.rs
+++ b/crates/api/tests/invoke_func_via_table.rs
@@ -16,7 +16,7 @@ fn test_invoke_func_via_table() -> Result<()> {
        "#,
    )?;
    let module = Module::new(&store, &binary).context("> Error compiling module!")?;
-    let instance = Instance::new(&store, &module, &[]).context("> Error instantiating module!")?;
+    let instance = Instance::new(&module, &[]).context("> Error instantiating module!")?;

    let f = instance
        .find_export_by_name("table")
--- a/crates/api/tests/traps.rs
+++ b/crates/api/tests/traps.rs
@@ -41,3 +41,116 @@ fn test_trap_return() -> Result<(), String> {

    Ok(())
 }
+
+#[test]
+fn test_trap_trace() -> Result<(), String> {
+    let store = Store::default();
+    let binary = parse_str(
+        r#"
+            (module $hello_mod
+                (func (export "run") (call $hello))
+                (func $hello (unreachable))
+            )
+        "#,
+    )
+    .map_err(|e| format!("failed to parse WebAssembly text source: {}", e))?;
+
+    let module =
+        Module::new(&store, &binary).map_err(|e| format!("failed to compile module: {}", e))?;
+    let instance = Instance::new(&module, &[])
+        .map_err(|e| format!("failed to instantiate module: {:?}", e))?;
+    let run_func = instance.exports()[0]
+        .func()
+        .expect("expected function export");
+
+    let e = run_func.call(&[]).err().expect("error calling function");
+
+    let trace = e.trace();
+    assert_eq!(trace.len(), 2);
+    assert_eq!(trace[0].module_name().unwrap(), "hello_mod");
+    assert_eq!(trace[0].func_index(), 1);
+    assert_eq!(trace[1].module_name().unwrap(), "hello_mod");
+    assert_eq!(trace[1].func_index(), 0);
+    assert!(e.message().contains("unreachable"));
+
+    Ok(())
+}
+
+#[test]
+fn test_trap_trace_cb() -> Result<(), String> {
+    struct ThrowCallback;
+
+    impl Callable for ThrowCallback {
+        fn call(&self, _params: &[Val], _results: &mut [Val]) -> Result<(), Trap> {
+            Err(Trap::new("cb throw"))
+        }
+    }
+
+    let store = Store::default();
+    let binary = parse_str(
+        r#"
+            (module $hello_mod
+                (import "" "throw" (func $throw))
+                (func (export "run") (call $hello))
+                (func $hello (call $throw))
+            )
+        "#,
+    )
+    .map_err(|e| format!("failed to parse WebAssembly text source: {}", e))?;
+
+    let fn_type = FuncType::new(Box::new([]), Box::new([]));
+    let fn_func = Func::new(&store, fn_type, Rc::new(ThrowCallback));
+
+    let module =
+        Module::new(&store, &binary).map_err(|e| format!("failed to compile module: {}", e))?;
+    let instance = Instance::new(&module, &[fn_func.into()])
+        .map_err(|e| format!("failed to instantiate module: {:?}", e))?;
+    let run_func = instance.exports()[0]
+        .func()
+        .expect("expected function export");
+
+    let e = run_func.call(&[]).err().expect("error calling function");
+
+    let trace = e.trace();
+    assert_eq!(trace.len(), 2);
+    assert_eq!(trace[0].module_name().unwrap(), "hello_mod");
+    assert_eq!(trace[0].func_index(), 1);
+    assert_eq!(trace[1].module_name().unwrap(), "hello_mod");
+    assert_eq!(trace[1].func_index(), 0);
+    assert_eq!(e.message(), "cb throw");
+
+    Ok(())
+}
+
+#[test]
+fn test_trap_stack_overflow() -> Result<(), String> {
+    let store = Store::default();
+    let binary = parse_str(
+        r#"
+            (module $rec_mod
+                (func $run (export "run") (call $run))
+            )
+        "#,
+    )
+    .map_err(|e| format!("failed to parse WebAssembly text source: {}", e))?;
+
+    let module =
+        Module::new(&store, &binary).map_err(|e| format!("failed to compile module: {}", e))?;
+    let instance = Instance::new(&module, &[])
+        .map_err(|e| format!("failed to instantiate module: {:?}", e))?;
+    let run_func = instance.exports()[0]
+        .func()
+        .expect("expected function export");
+
+    let e = run_func.call(&[]).err().expect("error calling function");
+
+    let trace = e.trace();
+    assert!(trace.len() >= 32);
+    for i in 0..trace.len() {
+        assert_eq!(trace[i].module_name().unwrap(), "rec_mod");
+        assert_eq!(trace[i].func_index(), 0);
+    }
+    assert!(e.message().contains("call stack exhausted"));
+
+    Ok(())
+}
--- a/crates/c-api/Cargo.toml
+++ b/crates/c-api/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "wasmtime-c-api"
+version = "0.9.0"
+authors = ["The Wasmtime Project Developers"]
+description = "C API to expose the Wasmtime runtime"
+license = "Apache-2.0 WITH LLVM-exception"
+repository = "https://github.com/bytecodealliance/wasmtime"
+readme = "README.md"
+edition = "2018"
+publish = false
+
+[lib]
+name = "wasmtime"
+crate-type = ["staticlib", "cdylib"]
+doc = false
+test = false
+doctest = false
+
+[dependencies]
+wasmtime = { path = "../api" }
--- a/crates/c-api/LICENSE
+++ b/crates/c-api/LICENSE
@@ -0,0 +1,220 @@
+
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+
--- a/crates/c-api/README.md
+++ b/crates/c-api/README.md
@@ -0,0 +1,3 @@
+# Implementation of wasm-c-api in Rust
+
+https://github.com/WebAssembly/wasm-c-api
--- a/crates/c-api/examples/Makefile
+++ b/crates/c-api/examples/Makefile
--- a/crates/c-api/examples/wasm-c-api
+++ b/crates/c-api/examples/wasm-c-api
--- a/crates/c-api/src/lib.rs
+++ b/crates/c-api/src/lib.rs
@@ -5,15 +5,14 @@

 // TODO complete the C API

-use super::{
-    AnyRef, Callable, Engine, ExportType, Extern, ExternType, Func, FuncType, Global, GlobalType,
-    ImportType, Instance, Limits, Memory, MemoryType, Module, Store, Table, TableType, Trap, Val,
-    ValType,
-};
-use crate::r#ref::{HostInfo, HostRef};
 use std::cell::RefCell;
 use std::rc::Rc;
 use std::{mem, ptr, slice};
+use wasmtime::{
+    AnyRef, Callable, Engine, ExportType, Extern, ExternType, Func, FuncType, Global, GlobalType,
+    HostInfo, HostRef, ImportType, Instance, Limits, Memory, MemoryType, Module, Store, Table,
+    TableType, Trap, Val, ValType,
+};

 macro_rules! declare_vec {
    ($name:ident, $elem_ty:path) => {
@@ -569,14 +568,18 @@ impl wasm_val_t {
    }
 }

-impl Callable for wasm_func_callback_t {
+struct Callback {
+    callback: wasm_func_callback_t,
+}
+
+impl Callable for Callback {
    fn call(&self, params: &[Val], results: &mut [Val]) -> Result<(), Trap> {
        let params = params
            .iter()
            .map(|p| wasm_val_t::from_val(p))
            .collect::<Vec<_>>();
        let mut out_results = vec![wasm_val_t::default(); results.len()];
-        let func = self.expect("wasm_func_callback_t fn");
+        let func = self.callback.expect("wasm_func_callback_t fn");
        let out = unsafe { func(params.as_ptr(), out_results.as_mut_ptr()) };
        if !out.is_null() {
            let trap: Box<wasm_trap_t> = unsafe { Box::from_raw(out) };
@@ -633,7 +636,7 @@ pub unsafe extern "C" fn wasm_func_new(
 ) -> *mut wasm_func_t {
    let store = &(*store).store.borrow();
    let ty = (*ty).functype.clone();
-    let callback = Rc::new(callback);
+    let callback = Rc::new(Callback { callback });
    let func = Box::new(wasm_func_t {
        ext: wasm_extern_t {
            which: ExternHost::Func(HostRef::new(Func::new(store, ty, callback))),
@@ -700,7 +703,7 @@ pub unsafe extern "C" fn wasm_instance_new(
    let module = &(*module).module.borrow();
    // FIXME(WebAssembly/wasm-c-api#126) what else can we do with the `store`
    // argument?
-    if !Store::ptr_eq(&store, module.store()) {
+    if !Store::same(&store, module.store()) {
        if !result.is_null() {
            let trap = Trap::new("wasm_store_t must match store in wasm_module_t");
            let trap = Box::new(wasm_trap_t {
@@ -1254,7 +1257,7 @@ pub unsafe extern "C" fn wasm_globaltype_content(
 pub unsafe extern "C" fn wasm_globaltype_mutability(
    gt: *const wasm_globaltype_t,
 ) -> wasm_mutability_t {
-    use super::Mutability::*;
+    use wasmtime::Mutability::*;
    match (*gt).globaltype.mutability() {
        Const => 0,
        Var => 1,
@@ -1411,7 +1414,7 @@ pub unsafe extern "C" fn wasm_globaltype_new(
    ty: *mut wasm_valtype_t,
    mutability: wasm_mutability_t,
 ) -> *mut wasm_globaltype_t {
-    use super::Mutability::*;
+    use wasmtime::Mutability::*;
    let ty = Box::from_raw(ty);
    let mutability = match mutability {
        0 => Const,
--- a/crates/environ/Cargo.toml
+++ b/crates/environ/Cargo.toml
@@ -13,9 +13,9 @@ edition = "2018"

 [dependencies]
 anyhow = "1.0"
-cranelift-codegen = { version = "0.54", features = ["enable-serde"] }
-cranelift-entity = { version = "0.54", features = ["enable-serde"] }
-cranelift-wasm = { version = "0.54", features = ["enable-serde"] }
+cranelift-codegen = { version = "0.55", features = ["enable-serde"] }
+cranelift-entity = { version = "0.55", features = ["enable-serde"] }
+cranelift-wasm = { version = "0.55", features = ["enable-serde"] }
 wasmparser = "0.47.0"
 lightbeam = { path = "../lightbeam", optional = true, version = "0.9.0" }
 indexmap = "1.0.2"
@@ -46,7 +46,7 @@ tempfile = "3"
 target-lexicon = { version = "0.10.0", default-features = false }
 pretty_env_logger = "0.3.0"
 rand = { version = "0.7.0", default-features = false, features = ["small_rng"] }
-cranelift-codegen = { version = "0.54", features = ["enable-serde", "all-arch"] }
+cranelift-codegen = { version = "0.55", features = ["enable-serde", "all-arch"] }
 filetime = "0.2.7"

 [badges]
--- a/crates/environ/src/cache/tests.rs
+++ b/crates/environ/src/cache/tests.rs
@@ -1,7 +1,9 @@
 use super::config::tests::test_prolog;
 use super::*;
 use crate::address_map::{FunctionAddressMap, InstructionAddressMap};
-use crate::compilation::{CompiledFunction, Relocation, RelocationTarget, TrapInformation};
+use crate::compilation::{
+    CompiledFunction, CompiledFunctionUnwindInfo, Relocation, RelocationTarget, TrapInformation,
+};
 use crate::module::{MemoryPlan, MemoryStyle, Module};
 use cranelift_codegen::{binemit, ir, isa, settings, ValueLocRange};
 use cranelift_entity::EntityRef;
@@ -259,7 +261,7 @@ fn new_module_cache_data(rng: &mut impl Rng) -> ModuleCacheData {
            CompiledFunction {
                body: (0..(i * 3 / 2)).collect(),
                jt_offsets: sm,
-                unwind_info: (0..(i * 3 / 2)).collect(),
+                unwind_info: CompiledFunctionUnwindInfo::Windows((0..(i * 3 / 2)).collect()),
            }
        })
        .collect();
--- a/crates/environ/src/compilation.rs
+++ b/crates/environ/src/compilation.rs
@@ -4,13 +4,136 @@
 use crate::cache::ModuleCacheDataTupleType;
 use crate::module;
 use crate::module_environ::FunctionBodyData;
-use cranelift_codegen::{binemit, ir, isa};
+use cranelift_codegen::{binemit, ir, isa, Context};
 use cranelift_entity::PrimaryMap;
 use cranelift_wasm::{DefinedFuncIndex, FuncIndex, ModuleTranslationState, WasmError};
 use serde::{Deserialize, Serialize};
 use std::ops::Range;
 use thiserror::Error;

+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+pub struct FDERelocEntry(pub i64, pub usize, pub u8);
+
+/// Relocation entry for unwind info.
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+pub struct CompiledFunctionUnwindInfoReloc {
+    /// Entry offest in the code block.
+    pub offset: u32,
+    /// Entry addend relative to the code block.
+    pub addend: u32,
+}
+
+/// Compiled function unwind information.
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
+pub enum CompiledFunctionUnwindInfo {
+    /// No info.
+    None,
+    /// Windows UNWIND_INFO.
+    Windows(Vec<u8>),
+    /// Frame layout info.
+    FrameLayout(Vec<u8>, usize, Vec<FDERelocEntry>),
+}
+
+impl CompiledFunctionUnwindInfo {
+    /// Constructs unwind info object.
+    pub fn new(isa: &dyn isa::TargetIsa, context: &Context) -> Self {
+        use cranelift_codegen::binemit::{
+            FrameUnwindKind, FrameUnwindOffset, FrameUnwindSink, Reloc,
+        };
+        use cranelift_codegen::isa::CallConv;
+
+        struct Sink(Vec<u8>, usize, Vec<FDERelocEntry>);
+        impl FrameUnwindSink for Sink {
+            fn len(&self) -> FrameUnwindOffset {
+                self.0.len()
+            }
+            fn bytes(&mut self, b: &[u8]) {
+                self.0.extend_from_slice(b);
+            }
+            fn reserve(&mut self, len: usize) {
+                self.0.reserve(len)
+            }
+            fn reloc(&mut self, r: Reloc, off: FrameUnwindOffset) {
+                self.2.push(FDERelocEntry(
+                    0,
+                    off,
+                    match r {
+                        Reloc::Abs4 => 4,
+                        Reloc::Abs8 => 8,
+                        _ => {
+                            panic!("unexpected reloc type");
+                        }
+                    },
+                ))
+            }
+            fn set_entry_offset(&mut self, off: FrameUnwindOffset) {
+                self.1 = off;
+            }
+        }
+
+        let kind = match context.func.signature.call_conv {
+            CallConv::SystemV | CallConv::Fast | CallConv::Cold => FrameUnwindKind::Libunwind,
+            CallConv::WindowsFastcall => FrameUnwindKind::Fastcall,
+            _ => {
+                return CompiledFunctionUnwindInfo::None;
+            }
+        };
+
+        let mut sink = Sink(Vec::new(), 0, Vec::new());
+        context.emit_unwind_info(isa, kind, &mut sink);
+
+        let Sink(data, offset, relocs) = sink;
+        if data.is_empty() {
+            return CompiledFunctionUnwindInfo::None;
+        }
+
+        match kind {
+            FrameUnwindKind::Fastcall => CompiledFunctionUnwindInfo::Windows(data),
+            FrameUnwindKind::Libunwind => {
+                CompiledFunctionUnwindInfo::FrameLayout(data, offset, relocs)
+            }
+        }
+    }
+
+    /// Retuns true is no unwind info data.
+    pub fn is_empty(&self) -> bool {
+        match self {
+            CompiledFunctionUnwindInfo::None => true,
+            CompiledFunctionUnwindInfo::Windows(d) => d.is_empty(),
+            CompiledFunctionUnwindInfo::FrameLayout(c, _, _) => c.is_empty(),
+        }
+    }
+
+    /// Returns size of serilized unwind info.
+    pub fn len(&self) -> usize {
+        match self {
+            CompiledFunctionUnwindInfo::None => 0,
+            CompiledFunctionUnwindInfo::Windows(d) => d.len(),
+            CompiledFunctionUnwindInfo::FrameLayout(c, _, _) => c.len(),
+        }
+    }
+
+    /// Serializes data into byte array.
+    pub fn serialize(&self, dest: &mut [u8], relocs: &mut Vec<CompiledFunctionUnwindInfoReloc>) {
+        match self {
+            CompiledFunctionUnwindInfo::None => (),
+            CompiledFunctionUnwindInfo::Windows(d) => {
+                dest.copy_from_slice(d);
+            }
+            CompiledFunctionUnwindInfo::FrameLayout(code, _fde_offset, r) => {
+                dest.copy_from_slice(code);
+                r.iter().for_each(move |r| {
+                    assert_eq!(r.2, 8);
+                    relocs.push(CompiledFunctionUnwindInfoReloc {
+                        offset: r.1 as u32,
+                        addend: r.0 as u32,
+                    })
+                });
+            }
+        }
+    }
+}
+
 /// Compiled function: machine code body, jump table offsets, and unwind information.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
 pub struct CompiledFunction {
@@ -21,7 +144,7 @@ pub struct CompiledFunction {
    pub jt_offsets: ir::JumpTableOffsets,

    /// The unwind information.
-    pub unwind_info: Vec<u8>,
+    pub unwind_info: CompiledFunctionUnwindInfo,
 }

 type Functions = PrimaryMap<DefinedFuncIndex, CompiledFunction>;
@@ -50,7 +173,7 @@ impl Compilation {
                .map(|(body_range, jt_offsets, unwind_range)| CompiledFunction {
                    body: buffer[body_range].to_vec(),
                    jt_offsets,
-                    unwind_info: buffer[unwind_range].to_vec(),
+                    unwind_info: CompiledFunctionUnwindInfo::Windows(buffer[unwind_range].to_vec()),
                })
                .collect(),
        )
--- a/crates/environ/src/cranelift.rs
+++ b/crates/environ/src/cranelift.rs
@@ -3,7 +3,8 @@
 use crate::address_map::{FunctionAddressMap, InstructionAddressMap};
 use crate::cache::{ModuleCacheData, ModuleCacheDataTupleType, ModuleCacheEntry};
 use crate::compilation::{
-    Compilation, CompileError, CompiledFunction, Relocation, RelocationTarget, TrapInformation,
+    Compilation, CompileError, CompiledFunction, CompiledFunctionUnwindInfo, Relocation,
+    RelocationTarget, TrapInformation,
 };
 use crate::func_environ::{
    get_func_name, get_imported_memory32_grow_name, get_imported_memory32_size_name,
@@ -204,6 +205,7 @@ impl crate::compilation::Compiler for Cranelift {
                        context.func.name = get_func_name(func_index);
                        context.func.signature =
                            module.signatures[module.functions[func_index]].clone();
+                        context.func.collect_frame_layout_info();
                        if generate_debug_info {
                            context.func.collect_debug_info();
                        }
@@ -217,7 +219,6 @@ impl crate::compilation::Compiler for Cranelift {
                        )?;

                        let mut code_buf: Vec<u8> = Vec::new();
-                        let mut unwind_info = Vec::new();
                        let mut reloc_sink = RelocSink::new(func_index);
                        let mut trap_sink = TrapSink::new();
                        let mut stackmap_sink = binemit::NullStackmapSink {};
@@ -233,7 +234,7 @@ impl crate::compilation::Compiler for Cranelift {
                                CompileError::Codegen(pretty_error(&context.func, Some(isa), error))
                            })?;

-                        context.emit_unwind_info(isa, &mut unwind_info);
+                        let unwind_info = CompiledFunctionUnwindInfo::new(isa, &context);

                        let address_transform = if generate_debug_info {
                            let body_len = code_buf.len();
--- a/crates/environ/src/func_environ.rs
+++ b/crates/environ/src/func_environ.rs
@@ -362,8 +362,8 @@ impl<'module_environment> TargetEnvironment for FuncEnvironment<'module_environm
 }

 impl<'module_environment> cranelift_wasm::FuncEnvironment for FuncEnvironment<'module_environment> {
-    fn is_wasm_parameter(&self, func: &ir::Function, index: usize) -> bool {
-        func.signature.params[index].purpose == ir::ArgumentPurpose::Normal
+    fn is_wasm_parameter(&self, signature: &ir::Signature, index: usize) -> bool {
+        signature.params[index].purpose == ir::ArgumentPurpose::Normal
    }

    fn make_table(&mut self, func: &mut ir::Function, index: TableIndex) -> WasmResult<ir::Table> {
--- a/crates/environ/src/lib.rs
+++ b/crates/environ/src/lib.rs
@@ -44,8 +44,9 @@ pub use crate::address_map::{
 };
 pub use crate::cache::{create_new_config as cache_create_new_config, init as cache_init};
 pub use crate::compilation::{
-    Compilation, CompileError, CompiledFunction, Compiler, Relocation, RelocationTarget,
-    Relocations, TrapInformation, Traps,
+    Compilation, CompileError, CompiledFunction, CompiledFunctionUnwindInfo,
+    CompiledFunctionUnwindInfoReloc, Compiler, Relocation, RelocationTarget, Relocations,
+    TrapInformation, Traps,
 };
 pub use crate::cranelift::Cranelift;
 pub use crate::data_structures::*;
--- a/crates/fuzzing/Cargo.toml
+++ b/crates/fuzzing/Cargo.toml
@@ -10,7 +10,7 @@ version = "0.9.0"

 [dependencies]
 anyhow = "1.0.22"
-arbitrary = "0.2.0"
+arbitrary = { version = "0.3.2", features = ["derive"] }
 binaryen = "0.8.2"
 env_logger = { version = "0.7.1", optional = true }
 log = "0.4.8"
--- a/crates/fuzzing/src/generators.rs
+++ b/crates/fuzzing/src/generators.rs
@@ -31,13 +31,17 @@ impl fmt::Debug for WasmOptTtf {
 }

 impl Arbitrary for WasmOptTtf {
-    fn arbitrary<U>(input: &mut U) -> Result<Self, U::Error>
-    where
-        U: Unstructured + ?Sized,
-    {
+    fn arbitrary(input: &mut Unstructured) -> arbitrary::Result<Self> {
        let seed: Vec<u8> = Arbitrary::arbitrary(input)?;
        let module = binaryen::tools::translate_to_fuzz_mvp(&seed);
        let wasm = module.write();
        Ok(WasmOptTtf { wasm })
    }
+
+    fn arbitrary_take_rest(input: Unstructured) -> arbitrary::Result<Self> {
+        let seed: Vec<u8> = Arbitrary::arbitrary_take_rest(input)?;
+        let module = binaryen::tools::translate_to_fuzz_mvp(&seed);
+        let wasm = module.write();
+        Ok(WasmOptTtf { wasm })
+    }
 }
--- a/crates/fuzzing/src/generators/api.rs
+++ b/crates/fuzzing/src/generators/api.rs
@@ -15,8 +15,9 @@
 //! [swarm testing]: https://www.cs.utah.edu/~regehr/papers/swarm12.pdf

 use arbitrary::{Arbitrary, Unstructured};
-use std::collections::HashSet;
+use std::collections::BTreeSet;

+#[derive(Arbitrary, Debug)]
 struct Swarm {
    config_debug_info: bool,
    module_new: bool,
@@ -26,24 +27,8 @@ struct Swarm {
    call_exported_func: bool,
 }

-impl Arbitrary for Swarm {
-    fn arbitrary<U>(input: &mut U) -> Result<Self, U::Error>
-    where
-        U: Unstructured + ?Sized,
-    {
-        Ok(Swarm {
-            config_debug_info: bool::arbitrary(input)?,
-            module_new: bool::arbitrary(input)?,
-            module_drop: bool::arbitrary(input)?,
-            instance_new: bool::arbitrary(input)?,
-            instance_drop: bool::arbitrary(input)?,
-            call_exported_func: bool::arbitrary(input)?,
-        })
-    }
-}
-
 /// A call to one of Wasmtime's public APIs.
-#[derive(Clone, Debug)]
+#[derive(Arbitrary, Clone, Debug)]
 #[allow(missing_docs)]
 pub enum ApiCall {
    ConfigNew,
@@ -61,8 +46,8 @@ use ApiCall::*;
 #[derive(Default)]
 struct Scope {
    id_counter: usize,
-    modules: HashSet<usize>,
-    instances: HashSet<usize>,
+    modules: BTreeSet<usize>,
+    instances: BTreeSet<usize>,
 }

 impl Scope {
@@ -81,10 +66,7 @@ pub struct ApiCalls {
 }

 impl Arbitrary for ApiCalls {
-    fn arbitrary<U>(input: &mut U) -> Result<Self, U::Error>
-    where
-        U: Unstructured + ?Sized,
-    {
+    fn arbitrary(input: &mut Unstructured) -> arbitrary::Result<Self> {
        let swarm = Swarm::arbitrary(input)?;
        let mut calls = vec![];

@@ -94,8 +76,8 @@ impl Arbitrary for ApiCalls {

        let mut scope = Scope::default();

-        for _ in 0..input.container_size()? {
-            let mut choices: Vec<fn(_, &mut Scope) -> Result<ApiCall, U::Error>> = vec![];
+        for _ in 0..input.arbitrary_len::<ApiCall>()? {
+            let mut choices: Vec<fn(_, &mut Scope) -> arbitrary::Result<ApiCall>> = vec![];

            if swarm.module_new {
                choices.push(|input, scope| {
@@ -108,7 +90,7 @@ impl Arbitrary for ApiCalls {
            if swarm.module_drop && !scope.modules.is_empty() {
                choices.push(|input, scope| {
                    let modules: Vec<_> = scope.modules.iter().cloned().collect();
-                    let id = arbitrary_choice(input, &modules)?.cloned().unwrap();
+                    let id = *input.choose(&modules)?;
                    scope.modules.remove(&id);
                    Ok(ModuleDrop { id })
                });
@@ -116,7 +98,7 @@ impl Arbitrary for ApiCalls {
            if swarm.instance_new && !scope.modules.is_empty() {
                choices.push(|input, scope| {
                    let modules: Vec<_> = scope.modules.iter().cloned().collect();
-                    let module = arbitrary_choice(input, &modules)?.cloned().unwrap();
+                    let module = *input.choose(&modules)?;
                    let id = scope.next_id();
                    scope.instances.insert(id);
                    Ok(InstanceNew { id, module })
@@ -125,7 +107,7 @@ impl Arbitrary for ApiCalls {
            if swarm.instance_drop && !scope.instances.is_empty() {
                choices.push(|input, scope| {
                    let instances: Vec<_> = scope.instances.iter().cloned().collect();
-                    let id = arbitrary_choice(input, &instances)?.cloned().unwrap();
+                    let id = *input.choose(&instances)?;
                    scope.instances.remove(&id);
                    Ok(InstanceDrop { id })
                });
@@ -133,43 +115,28 @@ impl Arbitrary for ApiCalls {
            if swarm.call_exported_func && !scope.instances.is_empty() {
                choices.push(|input, scope| {
                    let instances: Vec<_> = scope.instances.iter().cloned().collect();
-                    let instance = arbitrary_choice(input, &instances)?.cloned().unwrap();
+                    let instance = *input.choose(&instances)?;
                    let nth = usize::arbitrary(input)?;
                    Ok(CallExportedFunc { instance, nth })
                });
            }

-            if let Some(c) = arbitrary_choice(input, &choices)? {
-                calls.push(c(input, &mut scope)?);
-            } else {
+            if choices.is_empty() {
                break;
            }
+            let c = input.choose(&choices)?;
+            calls.push(c(input, &mut scope)?);
        }

        Ok(ApiCalls { calls })
    }
 }

-fn arbitrary_choice<'a, T, U>(input: &mut U, choices: &'a [T]) -> Result<Option<&'a T>, U::Error>
-where
-    U: Unstructured + ?Sized,
-{
-    if choices.is_empty() {
-        Ok(None)
-    } else {
-        let i = usize::arbitrary(input)? % choices.len();
-        Ok(Some(&choices[i]))
-    }
-}
-
-fn arbitrary_config<U>(
-    input: &mut U,
+fn arbitrary_config(
+    input: &mut Unstructured,
    swarm: &Swarm,
    calls: &mut Vec<ApiCall>,
-) -> Result<(), U::Error>
-where
-    U: Unstructured + ?Sized,
-{
+) -> arbitrary::Result<()> {
    calls.push(ConfigNew);

    if swarm.config_debug_info && bool::arbitrary(input)? {
--- a/crates/jit/Cargo.toml
+++ b/crates/jit/Cargo.toml
@@ -11,11 +11,11 @@ readme = "README.md"
 edition = "2018"

 [dependencies]
-cranelift-codegen = { version = "0.54", features = ["enable-serde"] }
-cranelift-entity = { version = "0.54", features = ["enable-serde"] }
-cranelift-wasm = { version = "0.54", features = ["enable-serde"] }
-cranelift-native = "0.54"
-cranelift-frontend = "0.54"
+cranelift-codegen = { version = "0.55", features = ["enable-serde"] }
+cranelift-entity = { version = "0.55", features = ["enable-serde"] }
+cranelift-wasm = { version = "0.55", features = ["enable-serde"] }
+cranelift-native = "0.55"
+cranelift-frontend = "0.55"
 wasmtime-environ = { path = "../environ", version = "0.9.0" }
 wasmtime-runtime = { path = "../runtime", version = "0.9.0" }
 wasmtime-debug = { path = "../debug", version = "0.9.0" }
--- a/crates/jit/src/action.rs
+++ b/crates/jit/src/action.rs
@@ -6,7 +6,7 @@ use std::cmp::max;
 use std::{fmt, mem, ptr, slice};
 use thiserror::Error;
 use wasmtime_environ::ir;
-use wasmtime_runtime::{wasmtime_call_trampoline, Export, InstanceHandle, VMInvokeArgument};
+use wasmtime_runtime::{wasmtime_call_trampoline, Export, InstanceHandle, Trap, VMInvokeArgument};

 /// A runtime value.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
@@ -100,10 +100,7 @@ pub enum ActionOutcome {
    },

    /// A trap occurred while the action was executing.
-    Trapped {
-        /// The trap message.
-        message: String,
-    },
+    Trapped(Trap),
 }

 /// An error detected while invoking a wasm function or reading a wasm global.
@@ -191,7 +188,7 @@ pub fn invoke(
    compiler.publish_compiled_code();

    // Call the trampoline.
-    if let Err(message) = unsafe {
+    if let Err(trap) = unsafe {
        instance.with_signals_on(|| {
            wasmtime_call_trampoline(
                callee_vmctx,
@@ -200,7 +197,7 @@ pub fn invoke(
            )
        })
    } {
-        return Ok(ActionOutcome::Trapped { message });
+        return Ok(ActionOutcome::Trapped(trap));
    }

    // Load the return values out of `values_vec`.
--- a/crates/jit/src/code_memory.rs
+++ b/crates/jit/src/code_memory.rs
@@ -2,14 +2,45 @@

 use crate::function_table::FunctionTable;
 use region;
+use std::mem::ManuallyDrop;
 use std::{cmp, mem};
 use wasmtime_environ::{Compilation, CompiledFunction};
 use wasmtime_runtime::{Mmap, VMFunctionBody};

+struct CodeMemoryEntry {
+    mmap: ManuallyDrop<Mmap>,
+    table: ManuallyDrop<FunctionTable>,
+}
+
+impl CodeMemoryEntry {
+    fn new() -> Self {
+        Self {
+            mmap: ManuallyDrop::new(Mmap::new()),
+            table: ManuallyDrop::new(FunctionTable::new()),
+        }
+    }
+    fn with_capacity(cap: usize) -> Result<Self, String> {
+        Ok(Self {
+            mmap: ManuallyDrop::new(Mmap::with_at_least(cap)?),
+            table: ManuallyDrop::new(FunctionTable::new()),
+        })
+    }
+}
+
+impl Drop for CodeMemoryEntry {
+    fn drop(&mut self) {
+        unsafe {
+            // Table needs to be freed before mmap.
+            ManuallyDrop::drop(&mut self.table);
+            ManuallyDrop::drop(&mut self.mmap);
+        }
+    }
+}
+
 /// Memory manager for executable code.
 pub struct CodeMemory {
-    current: (Mmap, FunctionTable),
-    mmaps: Vec<(Mmap, FunctionTable)>,
+    current: CodeMemoryEntry,
+    entries: Vec<CodeMemoryEntry>,
    position: usize,
    published: usize,
 }
@@ -23,8 +54,8 @@ impl CodeMemory {
    /// Create a new `CodeMemory` instance.
    pub fn new() -> Self {
        Self {
-            current: (Mmap::new(), FunctionTable::new()),
-            mmaps: Vec::new(),
+            current: CodeMemoryEntry::new(),
+            entries: Vec::new(),
            position: 0,
            published: 0,
        }
@@ -81,19 +112,20 @@ impl CodeMemory {
        self.push_current(0)
            .expect("failed to push current memory map");

-        for (m, t) in &mut self.mmaps[self.published..] {
+        for CodeMemoryEntry { mmap: m, table: t } in &mut self.entries[self.published..] {
+            // Remove write access to the pages due to the relocation fixups.
+            t.publish(m.as_ptr() as u64)
+                .expect("failed to publish function table");
+
            if !m.is_empty() {
                unsafe {
                    region::protect(m.as_mut_ptr(), m.len(), region::Protection::ReadExecute)
                }
                .expect("unable to make memory readonly and executable");
            }
-
-            t.publish(m.as_ptr() as u64)
-                .expect("failed to publish function table");
        }

-        self.published = self.mmaps.len();
+        self.published = self.entries.len();
    }

    /// Allocate `size` bytes of memory which can be made executable later by
@@ -103,7 +135,7 @@ impl CodeMemory {
    ///
    /// TODO: Add an alignment flag.
    fn allocate(&mut self, size: usize) -> Result<(&mut [u8], &mut FunctionTable), String> {
-        if self.current.0.len() - self.position < size {
+        if self.current.mmap.len() - self.position < size {
            self.push_current(cmp::max(0x10000, size))?;
        }

@@ -111,8 +143,8 @@ impl CodeMemory {
        self.position += size;

        Ok((
-            &mut self.current.0.as_mut_slice()[old_position..self.position],
-            &mut self.current.1,
+            &mut self.current.mmap.as_mut_slice()[old_position..self.position],
+            &mut self.current.table,
        ))
    }

@@ -153,12 +185,19 @@ impl CodeMemory {
        // Keep unwind information 32-bit aligned (round up to the nearest 4 byte boundary)
        let padding = ((func.body.len() + 3) & !3) - func.body.len();
        let (unwind, remainder) = remainder.split_at_mut(padding + func.unwind_info.len());
-        unwind[padding..].copy_from_slice(&func.unwind_info);
+        let mut relocs = Vec::new();
+        func.unwind_info
+            .serialize(&mut unwind[padding..], &mut relocs);

        let unwind_start = func_end + (padding as u32);
        let unwind_end = unwind_start + (func.unwind_info.len() as u32);

-        table.add_function(func_start, func_end, unwind_start);
+        relocs.iter_mut().for_each(move |r| {
+            r.offset += unwind_start;
+            r.addend += func_start;
+        });
+
+        table.add_function(func_start, func_end, unwind_start, &relocs);

        (unwind_end, remainder, table, vmfunc)
    }
@@ -174,20 +213,17 @@ impl CodeMemory {
    fn push_current(&mut self, new_size: usize) -> Result<(), String> {
        let previous = mem::replace(
            &mut self.current,
-            (
            if new_size == 0 {
-                    Mmap::new()
+                CodeMemoryEntry::new()
            } else {
-                    Mmap::with_at_least(cmp::max(0x10000, new_size))?
+                CodeMemoryEntry::with_capacity(cmp::max(0x10000, new_size))?
            },
-                FunctionTable::new(),
-            ),
        );

-        if !previous.0.is_empty() {
-            self.mmaps.push(previous);
+        if !previous.mmap.is_empty() {
+            self.entries.push(previous);
        } else {
-            assert_eq!(previous.1.len(), 0);
+            assert_eq!(previous.table.len(), 0);
        }

        self.position = 0;
--- a/crates/jit/src/compiler.rs
+++ b/crates/jit/src/compiler.rs
@@ -16,12 +16,12 @@ use wasmtime_environ::entity::{EntityRef, PrimaryMap};
 use wasmtime_environ::isa::{TargetFrontendConfig, TargetIsa};
 use wasmtime_environ::wasm::{DefinedFuncIndex, DefinedMemoryIndex};
 use wasmtime_environ::{
-    Compilation, CompileError, CompiledFunction, Compiler as _C, FunctionBodyData, Module,
-    ModuleVmctxInfo, Relocations, Traps, Tunables, VMOffsets,
+    Compilation, CompileError, CompiledFunction, CompiledFunctionUnwindInfo, Compiler as _C,
+    FunctionBodyData, Module, ModuleVmctxInfo, Relocations, Traps, Tunables, VMOffsets,
 };
 use wasmtime_runtime::{
-    get_mut_trap_registry, InstantiationError, SignatureRegistry, TrapRegistrationGuard,
-    VMFunctionBody,
+    get_mut_trap_registry, jit_function_registry, InstantiationError, SignatureRegistry,
+    TrapRegistrationGuard, VMFunctionBody,
 };

 /// Select which kind of compilation to use.
@@ -51,6 +51,7 @@ pub struct Compiler {

    code_memory: CodeMemory,
    trap_registration_guards: Vec<TrapRegistrationGuard>,
+    jit_function_ranges: Vec<(usize, usize)>,
    trampoline_park: HashMap<*const VMFunctionBody, *const VMFunctionBody>,
    signatures: SignatureRegistry,
    strategy: CompilationStrategy,
@@ -66,6 +67,7 @@ impl Compiler {
            isa,
            code_memory: CodeMemory::new(),
            trap_registration_guards: Vec::new(),
+            jit_function_ranges: Vec::new(),
            trampoline_park: HashMap::new(),
            signatures: SignatureRegistry::new(),
            fn_builder_ctx: FunctionBuilderContext::new(),
@@ -85,6 +87,10 @@ impl Drop for Compiler {
        // Having a custom drop implementation we are independent from the field order
        // in the struct what reduces potential human error.
        self.trap_registration_guards.clear();
+
+        for (start, end) in self.jit_function_ranges.iter() {
+            jit_function_registry::unregister(*start, *end);
+        }
    }
 }

@@ -155,6 +161,18 @@ impl Compiler {
            &mut self.trap_registration_guards,
        );

+        for (i, allocated) in allocated_functions.iter() {
+            let ptr = (*allocated) as *const VMFunctionBody;
+            let body_len = compilation.get(i).body.len();
+            self.jit_function_ranges
+                .push((ptr as usize, ptr as usize + body_len));
+            let tag = jit_function_registry::JITFunctionTag {
+                module_id: module.name.clone(),
+                func_index: i.index(),
+            };
+            jit_function_registry::register(ptr as usize, ptr as usize + body_len, tag);
+        }
+
        let dbg = if let Some(debug_data) = debug_data {
            let target_config = self.isa.frontend_config();
            let ofs = VMOffsets::new(target_config.pointer_bytes(), &module);
@@ -215,6 +233,7 @@ impl Compiler {
                    signature,
                    value_size,
                )?;
+
                entry.insert(body);
                body
            }
@@ -266,6 +285,7 @@ fn make_trampoline(

    let mut context = Context::new();
    context.func = ir::Function::with_name_signature(ir::ExternalName::user(0, 0), wrapper_sig);
+    context.func.collect_frame_layout_info();

    {
        let mut builder = FunctionBuilder::new(&mut context.func, fn_builder_ctx);
@@ -326,7 +346,6 @@ fn make_trampoline(
    }

    let mut code_buf = Vec::new();
-    let mut unwind_info = Vec::new();
    let mut reloc_sink = RelocSink {};
    let mut trap_sink = binemit::NullTrapSink {};
    let mut stackmap_sink = binemit::NullStackmapSink {};
@@ -346,7 +365,7 @@ fn make_trampoline(
            )))
        })?;

-    context.emit_unwind_info(isa, &mut unwind_info);
+    let unwind_info = CompiledFunctionUnwindInfo::new(isa, &context);

    Ok(code_memory
        .allocate_for_function(&CompiledFunction {
--- a/crates/jit/src/function_table.rs
+++ b/crates/jit/src/function_table.rs
@@ -2,42 +2,7 @@
 //!
 //! This module is primarily used to track JIT functions on Windows for stack walking and unwind.

-/// Represents a runtime function table.
-///
-/// The runtime function table is not implemented for non-Windows target platforms.
-#[cfg(not(target_os = "windows"))]
-pub(crate) struct FunctionTable;
-
-#[cfg(not(target_os = "windows"))]
-impl FunctionTable {
-    /// Creates a new function table.
-    pub fn new() -> Self {
-        Self
-    }
-
-    /// Returns the number of functions in the table, also referred to as its 'length'.
-    ///
-    /// For non-Windows platforms, the table will always be empty.
-    pub fn len(&self) -> usize {
-        0
-    }
-
-    /// Adds a function to the table based off of the start offset, end offset, and unwind offset.
-    ///
-    /// The offsets are from the "module base", which is provided when the table is published.
-    ///
-    /// For non-Windows platforms, this is a no-op.
-    pub fn add_function(&mut self, _start: u32, _end: u32, _unwind: u32) {}
-
-    /// Publishes the function table using the given base address.
-    ///
-    /// A published function table will automatically be deleted when it is dropped.
-    ///
-    /// For non-Windows platforms, this is a no-op.
-    pub fn publish(&mut self, _base_address: u64) -> Result<(), String> {
-        Ok(())
-    }
-}
+type FunctionTableReloc = wasmtime_environ::CompiledFunctionUnwindInfoReloc;

 /// Represents a runtime function table.
 ///
@@ -66,7 +31,14 @@ impl FunctionTable {
    /// Adds a function to the table based off of the start offset, end offset, and unwind offset.
    ///
    /// The offsets are from the "module base", which is provided when the table is published.
-    pub fn add_function(&mut self, start: u32, end: u32, unwind: u32) {
+    pub fn add_function(
+        &mut self,
+        start: u32,
+        end: u32,
+        unwind: u32,
+        _relocs: &[FunctionTableReloc],
+    ) {
+        assert_eq!(_relocs.len(), 0);
        use winapi::um::winnt;

        assert!(!self.published, "table has already been published");
@@ -133,3 +105,106 @@ impl Drop for FunctionTable {
        }
    }
 }
+
+/// Represents a runtime function table.
+///
+/// This is used to register JIT code with the operating system to enable stack walking and unwinding.
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+pub(crate) struct FunctionTable {
+    functions: Vec<u32>,
+    relocs: Vec<FunctionTableReloc>,
+    published: Option<Vec<usize>>,
+}
+
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+impl FunctionTable {
+    /// Creates a new function table.
+    pub fn new() -> Self {
+        Self {
+            functions: Vec::new(),
+            relocs: Vec::new(),
+            published: None,
+        }
+    }
+
+    /// Returns the number of functions in the table, also referred to as its 'length'.
+    pub fn len(&self) -> usize {
+        self.functions.len()
+    }
+
+    /// Adds a function to the table based off of the start offset, end offset, and unwind offset.
+    ///
+    /// The offsets are from the "module base", which is provided when the table is published.
+    pub fn add_function(
+        &mut self,
+        _start: u32,
+        _end: u32,
+        unwind: u32,
+        relocs: &[FunctionTableReloc],
+    ) {
+        assert!(self.published.is_none(), "table has already been published");
+        self.functions.push(unwind);
+        self.relocs.extend_from_slice(relocs);
+    }
+
+    /// Publishes the function table using the given base address.
+    ///
+    /// A published function table will automatically be deleted when it is dropped.
+    pub fn publish(&mut self, base_address: u64) -> Result<(), String> {
+        if self.published.is_some() {
+            return Err("function table was already published".into());
+        }
+
+        if self.functions.is_empty() {
+            assert_eq!(self.relocs.len(), 0);
+            self.published = Some(vec![]);
+            return Ok(());
+        }
+
+        extern "C" {
+            // libunwind import
+            fn __register_frame(fde: *const u8);
+        }
+
+        for reloc in self.relocs.iter() {
+            let addr = base_address + (reloc.offset as u64);
+            let target = base_address + (reloc.addend as u64);
+            unsafe {
+                std::ptr::write(addr as *mut u64, target);
+            }
+        }
+
+        let mut fdes = Vec::with_capacity(self.functions.len());
+        for unwind_offset in self.functions.iter() {
+            let addr = base_address + (*unwind_offset as u64);
+            let off = unsafe { std::ptr::read::<u32>(addr as *const u32) } as usize + 4;
+
+            let fde = (addr + off as u64) as usize;
+            unsafe {
+                __register_frame(fde as *const _);
+            }
+            fdes.push(fde);
+        }
+
+        self.published = Some(fdes);
+        Ok(())
+    }
+}
+
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+impl Drop for FunctionTable {
+    fn drop(&mut self) {
+        extern "C" {
+            // libunwind import
+            fn __deregister_frame(fde: *const u8);
+        }
+
+        if self.published.is_some() {
+            unsafe {
+                for fde in self.published.as_ref().unwrap() {
+                    __deregister_frame(*fde as *const _);
+                }
+            }
+        }
+    }
+}
--- a/crates/lightbeam/Cargo.toml
+++ b/crates/lightbeam/Cargo.toml
@@ -19,7 +19,7 @@ memoffset = "0.5.3"
 itertools = "0.8.2"
 capstone = "0.6.0"
 thiserror = "1.0.9"
-cranelift-codegen = "0.54"
+cranelift-codegen = "0.55"
 multi_mut = "0.1"
 either = "1.5"
 typemap = "0.3"
--- a/crates/misc/dotnet/Directory.Build.props
+++ b/crates/misc/dotnet/Directory.Build.props
@@ -2,5 +2,6 @@
  <PropertyGroup>
    <WasmtimeVersion>0.8.0</WasmtimeVersion>
    <WasmtimeLibraryName>wasmtime</WasmtimeLibraryName>
+    <WasmtimePackageName>wasmtime-c-api</WasmtimePackageName>
  </PropertyGroup>
 </Project>
--- a/crates/misc/dotnet/Directory.Build.targets
+++ b/crates/misc/dotnet/Directory.Build.targets
@@ -6,7 +6,7 @@
    <LibraryExtension Condition="'$(LibraryExtension)' == ''">.so</LibraryExtension>
    <WasmtimeLibraryFilename>$(LibraryPrefix)$(WasmtimeLibraryName)$(LibraryExtension)</WasmtimeLibraryFilename>
    <WasmtimeOutputPath>$(MSBuildThisFileDirectory)../../../target/$(Configuration.ToLower())</WasmtimeOutputPath>
-    <BuildWasmtimeCommand Condition="'$(Configuration)' == 'Release'">cargo build --release -p $(WasmtimeLibraryName)</BuildWasmtimeCommand> 
-    <BuildWasmtimeCommand Condition="'$(BuildWasmtimeCommand)' == ''">cargo build -p $(WasmtimeLibraryName)</BuildWasmtimeCommand> 
+    <BuildWasmtimeCommand Condition="'$(Configuration)' == 'Release'">cargo build --release -p $(WasmtimePackageName)</BuildWasmtimeCommand>
+    <BuildWasmtimeCommand Condition="'$(BuildWasmtimeCommand)' == ''">cargo build -p $(WasmtimePackageName)</BuildWasmtimeCommand>
  </PropertyGroup>
 </Project>
--- a/crates/runtime/Cargo.toml
+++ b/crates/runtime/Cargo.toml
@@ -20,6 +20,7 @@ indexmap = "1.0.2"
 thiserror = "1.0.4"
 more-asserts = "0.2.1"
 cfg-if = "0.1.9"
+backtrace = "0.3.42"

 [target.'cfg(target_os = "windows")'.dependencies]
 winapi = { version = "0.3.7", features = ["winbase", "memoryapi"] }
--- a/crates/runtime/src/instance.rs
+++ b/crates/runtime/src/instance.rs
@@ -9,7 +9,7 @@ use crate::memory::LinearMemory;
 use crate::mmap::Mmap;
 use crate::signalhandlers::{wasmtime_init_eager, wasmtime_init_finish};
 use crate::table::Table;
-use crate::traphandlers::wasmtime_call;
+use crate::traphandlers::{wasmtime_call, Trap};
 use crate::vmcontext::{
    VMBuiltinFunctionsArray, VMCallerCheckedAnyfunc, VMContext, VMFunctionBody, VMFunctionImport,
    VMGlobalDefinition, VMGlobalImport, VMMemoryDefinition, VMMemoryImport, VMSharedSignatureIndex,
@@ -1398,6 +1398,6 @@ pub enum InstantiationError {
    Link(#[from] LinkError),

    /// A compilation error occured.
-    #[error("Trap occurred while invoking start function: {0}")]
-    StartTrap(String),
+    #[error("Trap occurred while invoking start function")]
+    StartTrap(#[source] Trap),
 }
--- a/crates/runtime/src/jit_function_registry.rs
+++ b/crates/runtime/src/jit_function_registry.rs
@@ -0,0 +1,83 @@
+#![allow(missing_docs)]
+
+use lazy_static::lazy_static;
+use std::collections::BTreeMap;
+use std::sync::{Arc, RwLock};
+
+lazy_static! {
+    static ref REGISTRY: RwLock<JITFunctionRegistry> = RwLock::new(JITFunctionRegistry::default());
+}
+
+#[derive(Clone)]
+pub struct JITFunctionTag {
+    pub module_id: Option<String>,
+    pub func_index: usize,
+}
+
+impl std::fmt::Debug for JITFunctionTag {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if let Some(ref module_id) = self.module_id {
+            write!(f, "{}", module_id)?;
+        } else {
+            write!(f, "(module)")?;
+        }
+        write!(f, ":{}", self.func_index)
+    }
+}
+
+struct JITFunctionRegistry {
+    ranges: BTreeMap<usize, (usize, Arc<JITFunctionTag>)>,
+}
+
+impl Default for JITFunctionRegistry {
+    fn default() -> Self {
+        Self {
+            ranges: Default::default(),
+        }
+    }
+}
+
+impl JITFunctionRegistry {
+    fn register(&mut self, fn_start: usize, fn_end: usize, tag: JITFunctionTag) {
+        self.ranges.insert(fn_end, (fn_start, Arc::new(tag)));
+    }
+
+    fn unregister(&mut self, fn_end: usize) {
+        self.ranges.remove(&fn_end);
+    }
+
+    fn find(&self, pc: usize) -> Option<&Arc<JITFunctionTag>> {
+        self.ranges
+            .range(pc..)
+            .next()
+            .and_then(|(end, (start, s))| {
+                if *start <= pc && pc < *end {
+                    Some(s)
+                } else {
+                    None
+                }
+            })
+    }
+}
+
+pub fn register(fn_start: usize, fn_end: usize, tag: JITFunctionTag) {
+    REGISTRY
+        .write()
+        .expect("jit function registry lock got poisoned")
+        .register(fn_start, fn_end, tag);
+}
+
+pub fn unregister(_fn_start: usize, fn_end: usize) {
+    REGISTRY
+        .write()
+        .expect("jit function registry lock got poisoned")
+        .unregister(fn_end);
+}
+
+pub fn find(pc: usize) -> Option<Arc<JITFunctionTag>> {
+    REGISTRY
+        .read()
+        .expect("jit function registry lock got poisoned")
+        .find(pc)
+        .cloned()
+}
--- a/crates/runtime/src/lib.rs
+++ b/crates/runtime/src/lib.rs
@@ -34,6 +34,7 @@ mod trap_registry;
 mod traphandlers;
 mod vmcontext;

+pub mod jit_function_registry;
 pub mod libcalls;

 pub use crate::export::Export;
@@ -44,7 +45,7 @@ pub use crate::mmap::Mmap;
 pub use crate::sig_registry::SignatureRegistry;
 pub use crate::signalhandlers::{wasmtime_init_eager, wasmtime_init_finish};
 pub use crate::trap_registry::{get_mut_trap_registry, get_trap_registry, TrapRegistrationGuard};
-pub use crate::traphandlers::{wasmtime_call, wasmtime_call_trampoline};
+pub use crate::traphandlers::{wasmtime_call, wasmtime_call_trampoline, Trap};
 pub use crate::vmcontext::{
    VMCallerCheckedAnyfunc, VMContext, VMFunctionBody, VMFunctionImport, VMGlobalDefinition,
    VMGlobalImport, VMInvokeArgument, VMMemoryDefinition, VMMemoryImport, VMSharedSignatureIndex,
--- a/crates/runtime/src/traphandlers.rs
+++ b/crates/runtime/src/traphandlers.rs
@@ -4,7 +4,9 @@
 use crate::trap_registry::get_trap_registry;
 use crate::trap_registry::TrapDescription;
 use crate::vmcontext::{VMContext, VMFunctionBody};
+use backtrace::Backtrace;
 use std::cell::Cell;
+use std::fmt;
 use std::ptr;
 use wasmtime_environ::ir;

@@ -18,7 +20,7 @@ extern "C" {
 }

 thread_local! {
-    static RECORDED_TRAP: Cell<Option<TrapDescription>> = Cell::new(None);
+    static RECORDED_TRAP: Cell<Option<Trap>> = Cell::new(None);
    static JMP_BUF: Cell<*const u8> = Cell::new(ptr::null());
    static RESET_GUARD_PAGE: Cell<bool> = Cell::new(false);
 }
@@ -43,24 +45,26 @@ pub extern "C" fn CheckIfTrapAtAddress(_pc: *const u8) -> i8 {
 pub extern "C" fn RecordTrap(pc: *const u8, reset_guard_page: bool) {
    // TODO: please see explanation in CheckIfTrapAtAddress.
    let registry = get_trap_registry();
-    let trap_desc = registry
+    let trap = Trap {
+        desc: registry
            .get_trap(pc as usize)
            .unwrap_or_else(|| TrapDescription {
                source_loc: ir::SourceLoc::default(),
                trap_code: ir::TrapCode::StackOverflow,
-        });
+            }),
+        backtrace: Backtrace::new_unresolved(),
+    };

    if reset_guard_page {
        RESET_GUARD_PAGE.with(|v| v.set(true));
    }

    RECORDED_TRAP.with(|data| {
-        assert_eq!(
-            data.get(),
-            None,
+        let prev = data.replace(Some(trap));
+        assert!(
+            prev.is_none(),
            "Only one trap per thread can be recorded at a moment!"
        );
-        data.set(Some(trap_desc))
    });
 }

@@ -108,17 +112,34 @@ fn reset_guard_page() {
 #[cfg(not(target_os = "windows"))]
 fn reset_guard_page() {}

-fn trap_message() -> String {
-    let trap_desc = RECORDED_TRAP
-        .with(|data| data.replace(None))
-        .expect("trap_message must be called after trap occurred");
+/// Stores trace message with backtrace.
+#[derive(Debug)]
+pub struct Trap {
+    /// What sort of trap happened, as well as where in the original wasm module
+    /// it happened.
+    pub desc: TrapDescription,
+    /// Native stack backtrace at the time the trap occurred
+    pub backtrace: Backtrace,
+}

-    format!(
+impl fmt::Display for Trap {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
            "wasm trap: {}, source location: {}",
-        trap_code_to_expected_string(trap_desc.trap_code),
-        trap_desc.source_loc,
+            trap_code_to_expected_string(self.desc.trap_code),
+            self.desc.source_loc
        )
    }
+}
+
+impl std::error::Error for Trap {}
+
+fn last_trap() -> Trap {
+    RECORDED_TRAP
+        .with(|data| data.replace(None))
+        .expect("trap_message must be called after trap occurred")
+}

 fn trap_code_to_expected_string(trap_code: ir::TrapCode) -> String {
    use ir::TrapCode::*;
@@ -146,9 +167,9 @@ pub unsafe extern "C" fn wasmtime_call_trampoline(
    vmctx: *mut VMContext,
    callee: *const VMFunctionBody,
    values_vec: *mut u8,
-) -> Result<(), String> {
+) -> Result<(), Trap> {
    if WasmtimeCallTrampoline(vmctx as *mut u8, callee, values_vec) == 0 {
-        Err(trap_message())
+        Err(last_trap())
    } else {
        Ok(())
    }
@@ -160,9 +181,9 @@ pub unsafe extern "C" fn wasmtime_call_trampoline(
 pub unsafe extern "C" fn wasmtime_call(
    vmctx: *mut VMContext,
    callee: *const VMFunctionBody,
-) -> Result<(), String> {
+) -> Result<(), Trap> {
    if WasmtimeCall(vmctx as *mut u8, callee) == 0 {
-        Err(trap_message())
+        Err(last_trap())
    } else {
        Ok(())
    }
--- a/crates/wasi-c/Cargo.toml
+++ b/crates/wasi-c/Cargo.toml
@@ -14,9 +14,9 @@ edition = "2018"
 wasmtime-runtime = { path = "../runtime", version = "0.9.0" }
 wasmtime-environ = { path = "../environ", version = "0.9.0" }
 wasmtime-jit = { path = "../jit", version = "0.9.0" }
-cranelift-codegen = { version = "0.54", features = ["enable-serde"] }
-cranelift-entity = { version = "0.54", features = ["enable-serde"] }
-cranelift-wasm = { version = "0.54", features = ["enable-serde"] }
+cranelift-codegen = { version = "0.55", features = ["enable-serde"] }
+cranelift-entity = { version = "0.55", features = ["enable-serde"] }
+cranelift-wasm = { version = "0.55", features = ["enable-serde"] }
 target-lexicon = "0.10.0"
 log = { version = "0.4.8", default-features = false }
 libc = "0.2.60"
--- a/crates/wasi-common/src/sandboxed_tty_writer.rs
+++ b/crates/wasi-common/src/sandboxed_tty_writer.rs
@@ -1,4 +1,4 @@
-use std::io::{Result, Write};
+use std::io::{IoSlice, Result, Write};

 /// An adapter around a `Write` stream that guarantees that its output
 /// is valid UTF-8 and contains no control characters. It does this by
@@ -124,6 +124,27 @@ where
        return Ok(result);
    }

+    fn write_vectored(&mut self, bufs: &[IoSlice]) -> Result<usize> {
+        // Terminal output is [not expected to be atomic], so just write all the
+        // individual buffers in sequence.
+        //
+        // [not expected to be atomic]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/read.html#tag_16_474_08
+        let mut total_written = 0;
+
+        for buf in bufs {
+            let written = self.write(buf)?;
+
+            total_written += written;
+
+            // Stop at the first point where the OS writes less than we asked.
+            if written < buf.len() {
+                break;
+            }
+        }
+
+        Ok(total_written)
+    }
+
    fn flush(&mut self) -> Result<()> {
        self.inner.flush()
    }
--- a/crates/wasi/Cargo.toml
+++ b/crates/wasi/Cargo.toml
@@ -16,9 +16,9 @@ wasmtime-runtime = { path = "../runtime", version = "0.9.0" }
 wasmtime-environ = { path = "../environ", version = "0.9.0" }
 wasmtime-jit = { path = "../jit", version = "0.9.0" }
 wasi-common = { path = "../wasi-common", version = "0.9.0" }
-cranelift-codegen = { version = "0.54", features = ["enable-serde"] }
-cranelift-entity = { version = "0.54", features = ["enable-serde"] }
-cranelift-wasm = { version = "0.54", features = ["enable-serde"] }
+cranelift-codegen = { version = "0.55", features = ["enable-serde"] }
+cranelift-entity = { version = "0.55", features = ["enable-serde"] }
+cranelift-wasm = { version = "0.55", features = ["enable-serde"] }
 target-lexicon = "0.10.0"
 log = { version = "0.4.8", default-features = false }
 wig = { path = "../wasi-common/wig", version = "0.9.2" }
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -15,7 +15,7 @@ log = "0.4.8"
 wasmtime-fuzzing = { path = "../crates/fuzzing", features = ["env_logger"] }
 wasmtime-jit = { path = "../crates/jit" }
 wasmtime = { path = "../crates/api" }
-libfuzzer-sys = { git = "https://github.com/rust-fuzz/libfuzzer-sys.git" }
+libfuzzer-sys = "0.2.0"

 [[bin]]
 name = "compile"
--- a/scripts/cranelift-version.sh
+++ b/scripts/cranelift-version.sh
@@ -9,7 +9,7 @@ topdir=$(dirname "$0")/..
 cd "$topdir"

 # All the cranelift-* crates have the same version number
-version="0.53"
+version="0.55"

 # Update all of the Cargo.toml files.
 echo "Updating crate versions to $version"
--- a/src/commands/run.rs
+++ b/src/commands/run.rs
@@ -17,8 +17,7 @@ use wasmtime_interface_types::ModuleData;
 use wasmtime_wasi::{
    create_wasi_instance, old::snapshot_0::create_wasi_instance as create_wasi_instance_snapshot_0,
 };
-#[cfg(feature = "wasi-c")]
-use wasmtime_wasi_c::instantiate_wasi_c;
+
 #[cfg(feature = "wasi-c")]
 use wasmtime_wasi_c::instantiate_wasi_c;

@@ -152,7 +151,8 @@ impl RunCommand {
            #[cfg(feature = "wasi-c")]
            {
                let global_exports = store.global_exports().clone();
-                let handle = instantiate_wasi_c(global_exports, &preopen_dirs, &argv, &self.vars)?;
+                let handle =
+                    instantiate_wasi_c("", global_exports, &preopen_dirs, &argv, &self.vars)?;
                Instance::from_handle(&store, handle)
            }
            #[cfg(not(feature = "wasi-c"))]
--- a/tests/custom_signal_handler.rs
+++ b/tests/custom_signal_handler.rs
@@ -128,9 +128,12 @@ mod tests {
        {
            println!("calling read_out_of_bounds...");
            let trap = invoke_export(&instance, "read_out_of_bounds").unwrap_err();
-            assert!(trap
-                .message()
-                .starts_with("call error: wasm trap: out of bounds memory access"));
+            assert!(
+                trap.message()
+                    .starts_with("wasm trap: out of bounds memory access"),
+                "bad trap message: {:?}",
+                trap.message()
+            );
        }

        // these invoke wasmtime_call_trampoline from callable.rs
@@ -151,7 +154,7 @@ mod tests {
            let trap = read_out_of_bounds_func.call(&[]).unwrap_err();
            assert!(trap
                .message()
-                .starts_with("call error: wasm trap: out of bounds memory access"));
+                .starts_with("wasm trap: out of bounds memory access"));
        }
        Ok(())
    }