Make more code work with no_std. (#407)

* Make more code work with no_std.

no_std support is still incomplete, but this patch takes care of the
bulk of the straightforward parts.

wasmtime-debug/Cargo.toml

@@ -22,11 +22,12 @@ wasmtime-environ = { path = "../wasmtime-environ", default-features = false }
 target-lexicon = { version = "0.8.1", default-features = false }
 failure = { version = "0.1.3", default-features = false }
 failure_derive = { version = "0.1.3", default-features = false }
+hashbrown = { version = "0.6.0", optional = true }
 
 [features]
 default = ["std"]
 std = ["cranelift-codegen/std", "cranelift-wasm/std", "wasmtime-environ/std"]
-core = ["cranelift-codegen/core", "cranelift-wasm/core"]
+core = ["hashbrown/nightly", "cranelift-codegen/core", "cranelift-wasm/core"]
 
 [badges]
 maintenance = { status = "experimental" }

wasmtime-debug/src/gc.rs

@@ -1,9 +1,9 @@
 use crate::transform::AddressTransform;
+use crate::{HashMap, HashSet};
+use alloc::vec::Vec;
 use gimli::constants;
 use gimli::read;
 use gimli::{Reader, UnitSectionOffset};
-use std::collections::{HashMap, HashSet};
-use std::vec::Vec;
 
 #[derive(Debug)]
 pub struct Dependencies {
@@ -20,7 +20,7 @@ impl Dependencies {
     }
 
     fn add_edge(&mut self, a: UnitSectionOffset, b: UnitSectionOffset) {
-        use std::collections::hash_map::Entry;
+        use crate::hash_map::Entry;
         match self.edges.entry(a) {
             Entry::Occupied(mut o) => {
                 o.get_mut().insert(b);

wasmtime-debug/src/lib.rs

@@ -1,10 +1,18 @@
 //! Debug utils for WebAssembly using Cranelift.
+
+use alloc::string::String;
+use alloc::vec::Vec;
 use cranelift_codegen::isa::TargetFrontendConfig;
 use faerie::{Artifact, Decl};
 use failure::Error;
 use target_lexicon::{BinaryFormat, Triple};
 use wasmtime_environ::{ModuleAddressMap, ModuleVmctxInfo, ValueLabelsRanges};
 
+#[cfg(not(feature = "std"))]
+use hashbrown::{hash_map, HashMap, HashSet};
+#[cfg(feature = "std")]
+use std::collections::{hash_map, HashMap, HashSet};
+
 pub use crate::read_debuginfo::{read_debuginfo, DebugInfoData, WasmFileInfo};
 pub use crate::transform::transform_dwarf;
 pub use crate::write_debuginfo::{emit_dwarf, ResolvedSymbol, SymbolResolver};
@@ -16,6 +24,7 @@ mod write_debuginfo;
 
 #[macro_use]
 extern crate failure_derive;
+extern crate alloc;
 
 struct FunctionRelocResolver {}
 impl SymbolResolver for FunctionRelocResolver {
@@ -71,12 +80,12 @@ pub fn emit_debugsections_image(
     assert!(funcs.len() > 0);
     let mut segment_body: (usize, usize) = (!0, 0);
     for (body_ptr, body_len) in funcs.iter() {
-        segment_body.0 = ::std::cmp::min(segment_body.0, *body_ptr as usize);
-        segment_body.1 = ::std::cmp::max(segment_body.1, *body_ptr as usize + body_len);
+        segment_body.0 = ::core::cmp::min(segment_body.0, *body_ptr as usize);
+        segment_body.1 = ::core::cmp::max(segment_body.1, *body_ptr as usize + body_len);
     }
     let segment_body = (segment_body.0 as *const u8, segment_body.1 - segment_body.0);
 
-    let body = unsafe { ::std::slice::from_raw_parts(segment_body.0, segment_body.1) };
+    let body = unsafe { ::core::slice::from_raw_parts(segment_body.0, segment_body.1) };
     obj.declare_with("all", Decl::function(), body.to_vec())?;
 
     emit_dwarf(&mut obj, dwarf, &resolver)?;

wasmtime-debug/src/read_debuginfo.rs

@@ -1,3 +1,6 @@
+use alloc::boxed::Box;
+use alloc::string::String;
+use alloc::vec::Vec;
 use std::collections::HashMap;
 use std::path::PathBuf;
 use wasmparser::{self, ModuleReader, SectionCode};

wasmtime-debug/src/transform/address_transform.rs

@@ -1,12 +1,13 @@
+use crate::HashMap;
 use crate::WasmFileInfo;
+use alloc::boxed::Box;
+use alloc::collections::BTreeMap;
+use alloc::vec::Vec;
+use core::iter::FromIterator;
 use cranelift_codegen::ir::SourceLoc;
 use cranelift_entity::{EntityRef, PrimaryMap};
 use cranelift_wasm::DefinedFuncIndex;
 use gimli::write;
-use std::boxed::Box;
-use std::collections::{BTreeMap, HashMap};
-use std::iter::FromIterator;
-use std::vec::Vec;
 use wasmtime_environ::{FunctionAddressMap, ModuleAddressMap};
 
 pub type GeneratedAddress = usize;
@@ -160,7 +161,7 @@ fn build_function_lookup(
                 active_ranges.clone().into_boxed_slice(),
             );
         }
-        active_ranges.retain(|r| ranges[*r].wasm_end.cmp(&wasm_start) != std::cmp::Ordering::Less);
+        active_ranges.retain(|r| ranges[*r].wasm_end.cmp(&wasm_start) != core::cmp::Ordering::Less);
         active_ranges.push(range_index);
         last_wasm_pos = Some(wasm_start);
     }
@@ -491,10 +492,10 @@ impl AddressTransform {
 mod tests {
     use super::{build_function_lookup, get_wasm_code_offset, AddressTransform};
     use crate::read_debuginfo::WasmFileInfo;
+    use core::iter::FromIterator;
     use cranelift_codegen::ir::SourceLoc;
     use cranelift_entity::PrimaryMap;
     use gimli::write::Address;
-    use std::iter::FromIterator;
     use wasmtime_environ::{FunctionAddressMap, InstructionAddressMap, ModuleAddressMap};
 
     #[test]

wasmtime-debug/src/transform/attr.rs

@@ -1,5 +1,6 @@
+use crate::HashMap;
+use alloc::vec::Vec;
 use failure::Error;
-use std::collections::HashMap;
 
 use gimli;
 

wasmtime-debug/src/transform/expression.rs

@@ -1,3 +1,5 @@
+use crate::{HashMap, HashSet};
+use alloc::vec::Vec;
 use cranelift_codegen::ir::{StackSlots, ValueLabel, ValueLoc};
 use cranelift_codegen::isa::RegUnit;
 use cranelift_codegen::ValueLabelsRanges;
@@ -6,7 +8,6 @@ use cranelift_wasm::{get_vmctx_value_label, DefinedFuncIndex};
 use failure::Error;
 use gimli::write;
 use gimli::{self, Expression, Operation, Reader, ReaderOffset, Register, X86_64};
-use std::collections::{HashMap, HashSet};
 
 use super::address_transform::AddressTransform;
 
@@ -193,7 +194,7 @@ impl CompiledExpression {
         addr_tr: &AddressTransform,
         frame_info: Option<&FunctionFrameInfo>,
         endian: gimli::RunTimeEndian,
-    ) -> std::vec::Vec<(write::Address, u64, write::Expression)> {
+    ) -> alloc::vec::Vec<(write::Address, u64, write::Expression)> {
         if scope.len() == 0 {
             return vec![];
         }

wasmtime-debug/src/transform/line_program.rs

@@ -1,7 +1,8 @@
+use alloc::collections::BTreeMap;
+use alloc::vec::Vec;
+use core::iter::FromIterator;
 use cranelift_entity::EntityRef;
 use failure::Error;
-use std::collections::BTreeMap;
-use std::iter::FromIterator;
 
 use gimli;
 

wasmtime-debug/src/transform/mod.rs

@@ -1,9 +1,9 @@
 use crate::gc::build_dependencies;
 use crate::DebugInfoData;
+use crate::HashSet;
 use cranelift_codegen::isa::TargetFrontendConfig;
 use failure::Error;
 use simulate::generate_simulated_dwarf;
-use std::collections::HashSet;
 use wasmtime_environ::{ModuleAddressMap, ModuleVmctxInfo, ValueLabelsRanges};
 
 use gimli;

wasmtime-debug/src/transform/range_info_builder.rs

@@ -1,3 +1,4 @@
+use alloc::vec::Vec;
 use cranelift_entity::EntityRef;
 use cranelift_wasm::DefinedFuncIndex;
 use failure::Error;

wasmtime-debug/src/transform/simulate.rs

@@ -1,9 +1,11 @@
 use crate::read_debuginfo::WasmFileInfo;
 pub use crate::read_debuginfo::{DebugInfoData, FunctionMetadata, WasmType};
+use crate::{HashMap, HashSet};
+use alloc::string::String;
+use alloc::vec::Vec;
 use cranelift_entity::EntityRef;
 use cranelift_wasm::get_vmctx_value_label;
 use failure::Error;
-use std::collections::{HashMap, HashSet};
 use std::path::PathBuf;
 use wasmtime_environ::{ModuleVmctxInfo, ValueLabelsRanges};
 

wasmtime-debug/src/transform/unit.rs

@@ -1,6 +1,8 @@
+use crate::{HashMap, HashSet};
+use alloc::string::String;
+use alloc::vec::Vec;
 use cranelift_entity::EntityRef;
 use failure::Error;
-use std::collections::{HashMap, HashSet};
 use wasmtime_environ::{ModuleVmctxInfo, ValueLabelsRanges};
 
 use gimli;

wasmtime-debug/src/transform/utils.rs

@@ -1,3 +1,4 @@
+use alloc::vec::Vec;
 use cranelift_wasm::DefinedFuncIndex;
 use failure::Error;
 use wasmtime_environ::{ModuleVmctxInfo, ValueLabelsRanges};

wasmtime-debug/src/write_debuginfo.rs

@@ -1,9 +1,11 @@
+use alloc::string::String;
+use alloc::vec::Vec;
 use gimli::write::{Address, Dwarf, EndianVec, Result, Sections, Writer};
 use gimli::{RunTimeEndian, SectionId};
 
+use core::result;
 use faerie::artifact::{Decl, SectionKind};
 use faerie::*;
-use std::result;
 
 #[derive(Clone)]
 struct DebugReloc {