Implement ReadyToRunHelperNode for WASM

[Copilot]

Adds WASM code emission for ReadyToRun static-base, delegate-construction, and virtual-function helpers.

• Registers WASM function signatures with dependency analysis.
• Emits architecture-equivalent WASM helper bodies.
• Preserves shadow-stack and portable-entrypoint arguments across managed tail calls.

Note

This description was generated by GitHub Copilot.

• Fixes Implement ReadyToRunHelperNode for WASM #133738

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[Copilot]

🟡 Changes recommended

One or more issues must be addressed before approval.

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Review details

Suppressed comments (1)

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/Target_Wasm/WasmReadyToRunHelperNode.cs:71

• These ReturnCall targets are managed entry points (HelperEntrypoint and target.Constructor). In ReadyToRun, WasmLowering gives every managed call the layout $sp, visible args, pep_ptr, but these sequences forward only $sp and the visible arguments, so the generated calls have the wrong arity and cannot preserve the incoming portable entrypoint. The NativeAOT reply does not address the ReadyToRun build of this shared file; append the final incoming local under #if READYTORUN to each managed tail call in this switch.

                            expressions.Add(ControlFlow.ReturnCall(helper));

• Files reviewed: 4/4 changed files
• Comments generated: 1
• Review effort level: Lite

[Copilot]

🟡 Changes recommended

Unresolved critical and moderate issues include a compile-time regression and incorrect WASM relocation handling.

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Review details

Suppressed comments (2)

src/coreclr/tools/Common/JitInterface/WasmLowering.cs:563

• Removing the MethodDesc overloads here breaks existing READYTORUN callers that still invoke WasmLowering.GetSignature(MethodDesc) and GetLoweringFlags(MethodDesc) (for example ReadyToRunCodegenNodeFactory.cs:1517, CorInfoImpl.ReadyToRun.cs, and WasmImportThunkPortableEntrypoint.cs). This is a compile-time regression; keep those overloads or update every caller in the same change.

        public static WasmSignature GetSignature(INodeWithTypeSignature node)
        {
            return GetSignature(node.Signature, GetLoweringFlags(node));
        }

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/Target_Wasm/WasmReadyToRunHelperNode.cs:160

• I32.ConstRVA encodes a linear-memory address, but target.GetTargetNode(factory) is a method entry/function pointer for the CanonicalEntrypoint and ExactCallableAddress delegate cases. The WASM ABI uses WASM_TABLE_INDEX_SLEB for function pointers (see CorInfoTypes.cs:516-519 and emitwasm.cpp:1031-1035), so these delegates receive an image/data address rather than a callable table index; target.Thunk on line 165 has the same problem. Keep DispatchCell as a memory address, but emit method/thunk symbols with a table-index relocation.

[!NOTE] This review comment was created by GitHub Copilot.

                            expressions.Add(I32.ConstRVA(target.GetTargetNode(factory)));
                        }

• Files reviewed: 8/8 changed files
• Comments generated: 2
• Review effort level: Lite

[Copilot]

🟡 Changes recommended

Critical unresolved overload and duplicate-declaration issues remain.

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Review details

• Files reviewed: 9/9 changed files
• Comments generated: 2
• Review effort level: Lite

[Copilot]

🔵 Needs a closer look

One or more issues must be addressed before approval.

Review details

Suppressed comments (2)

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/Target_Wasm/WasmReadyToRunHelperNode.cs:159

• target.GetTargetNode(factory) is a method entrypoint, but I32.ConstRVA emits WASM_MEMORY_ADDR_REL_SLEB. Function pointers in the Wasm ABI require a table-index relocation (WASM_TABLE_INDEX_SLEB); the JIT uses that relocation for IF_FUNCPTR, and the current value will not identify the delegate target in the function table. Emit a table-index constant for this method pointer (and use the same fix for the thunk below).

                            expressions.Add(I32.ConstRVA(target.GetTargetNode(factory)));

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/Target_Wasm/WasmReadyToRunHelperNode.cs:50

• The new hand-authored helper bodies have no focused regression coverage for the static-base cctor paths or virtual-function resolution. The existing WASM tests cover signature/argument-layout calculations and interpreter-transition thunks, so a wrong local/stack sequence or helper relocation here could still pass those tests; add a WASM NativeAOT test that exercises these helper paths.

        protected override void EmitCode(NodeFactory factory, ref WasmEmitter encoder, bool relocsOnly)
        {
            Debug.Assert(!encoder.Is64Bit);

            List<WasmExpr> expressions = new List<WasmExpr>();

• Files reviewed: 6/6 changed files
• Comments generated: 0 new
• Review effort level: Lite

[Copilot]

🟡 Changes recommended

One or more issues must be addressed before approval.

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Review details

Suppressed comments (1)

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/Target_Wasm/WasmReadyToRunHelperNode.cs:203

• This adds several independent WASM helper paths, but no test exercises the generated static-base, delegate-constructor, or virtual/interface helper bodies. The existing browser WASM test covers R2R/interpreter transition signatures and does not reach these helpers, so malformed function signatures, tail-call argument lists, and helper relocations can regress without detection. Add focused WASM coverage for at least lazy statics, delegate construction, and interface/non-interface dispatch.

            encoder.FunctionBody = new WasmFunctionBody(WasmLowering.GetSignature(this).FuncType, expressions.ToArray());

• Files reviewed: 6/6 changed files
• Comments generated: 1
• Review effort level: Lite