Add lldb smoke test (#1241)

* add lldb runner

* don't build wasmtime

* use brew's lldb

* disable for macos

* set LLDB on linux

* re-org gh actions and cfg

* address feedback

.github/actions/define-dwarfdump-env/README.md

@@ -1,3 +0,0 @@
-# define-dwarfdump-env
-
-Defines `DWARFDUMP` path executable.

.github/actions/define-llvm-env/README.md

@@ -0,0 +1,3 @@
+# define-llvm-env
+
+Defines `DWARFDUMP` and `LLDB` path executable.

.github/actions/define-llvm-env/main.js

@@ -3,9 +3,11 @@
 // On OSX pointing to brew's LLVM location.
 if (process.platform == 'darwin') {
   console.log("::set-env name=DWARFDUMP::/usr/local/opt/llvm/bin/llvm-dwarfdump");
+  console.log("::set-env name=LLDB::/usr/local/opt/llvm/bin/lldb");
 }
 
 // On Linux pointing to specific version
 if (process.platform == 'linux') {
   console.log("::set-env name=DWARFDUMP::/usr/bin/llvm-dwarfdump-9");
+  console.log("::set-env name=LLDB::/usr/bin/lldb-9");
 }

.github/workflows/main.yml

@@ -164,7 +164,7 @@ jobs:
     - uses: ./.github/actions/install-rust
       with:
         toolchain: ${{ matrix.rust }}
-    - uses: ./.github/actions/define-dwarfdump-env
+    - uses: ./.github/actions/define-llvm-env
 
     - name: Install libclang
       # Note: libclang is pre-installed on the macOS and linux images.
@@ -202,6 +202,7 @@ jobs:
 
     # Test debug (DWARF) related functionality.
     - run: cargo test test_debug_dwarf_ -- --ignored --nocapture --test-threads 1
+      if: matrix.os == 'ubuntu-latest' 
       env:
         RUST_BACKTRACE: 1
         RUSTFLAGS: "-D warnings"

tests/debug/lldb.rs

@@ -0,0 +1,94 @@
+#![allow(dead_code)]
+
+use anyhow::{bail, format_err, Result};
+use filecheck::{CheckerBuilder, NO_VARIABLES};
+use std::env;
+use std::io::Write;
+use std::process::Command;
+use tempfile::NamedTempFile;
+
+fn lldb_with_script(args: &[&str], script: &str) -> Result<String> {
+    let lldb_path = env::var("LLDB").unwrap_or("lldb".to_string());
+    let mut cmd = Command::new(&lldb_path);
+
+    cmd.arg("--batch");
+    if cfg!(target_os = "macos") {
+        cmd.args(&["-o", "settings set plugin.jit-loader.gdb.enable on"]);
+    }
+    let mut script_file = NamedTempFile::new()?;
+    script_file.write(script.as_bytes())?;
+    let script_path = script_file.path().to_str().unwrap();
+    cmd.args(&["-s", &script_path]);
+
+    let mut me = std::env::current_exe().expect("current_exe specified");
+    me.pop(); // chop off the file name
+    me.pop(); // chop off `deps`
+    me.push("wasmtime");
+    cmd.arg(me);
+
+    cmd.arg("--");
+    cmd.args(args);
+
+    let output = cmd.output().expect("success");
+    if !output.status.success() {
+        bail!(
+            "failed to execute {:?}: {}",
+            cmd,
+            String::from_utf8_lossy(&output.stderr),
+        );
+    }
+    Ok(String::from_utf8(output.stdout)?)
+}
+
+fn check_lldb_output(output: &str, directives: &str) -> Result<()> {
+    let mut builder = CheckerBuilder::new();
+    builder
+        .text(directives)
+        .map_err(|e| format_err!("unable to build checker: {:?}", e))?;
+    let checker = builder.finish();
+    let check = checker
+        .explain(output, NO_VARIABLES)
+        .map_err(|e| format_err!("{:?}", e))?;
+    assert!(check.0, "didn't pass check {}", check.1);
+    Ok(())
+}
+
+#[test]
+#[ignore]
+#[cfg(all(
+    any(target_os = "linux", target_os = "macos"),
+    target_pointer_width = "64"
+))]
+pub fn test_debug_dwarf_lldb() -> Result<()> {
+    let output = lldb_with_script(
+        &[
+            "-g",
+            "tests/debug/testsuite/fib-wasm.wasm",
+            "--invoke",
+            "fib",
+            "3",
+        ],
+        r#"b fib
+r
+fr v
+c"#,
+    )?;
+
+    check_lldb_output(
+        &output,
+        r#"
+check: Breakpoint 1: no locations (pending)
+check: Unable to resolve breakpoint to any actual locations.
+check: 1 location added to breakpoint 1
+check: stop reason = breakpoint 1.1
+check: frame #0
+sameln: JIT
+sameln: fib(n=3)
+check: n = 3
+check: a = 0
+check: resuming
+check: exited with status
+"#,
+    )?;
+    Ok(())
+}

tests/debug/main.rs

@@ -1,4 +1,5 @@
 mod dump;
+mod lldb;
 mod obj;
 mod simulate;
 mod translate;