[WebAssembly] Added Debug Fixup pass

This pass changes debug_value instructions referring to stackified registers into TI_OPERAND_STACK with correct stack depth.

1 files changed, 17 insertions, 1 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 8a92abd..ca098427 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -45,6 +45,16 @@ static cl::opt<bool> EnableEmSjLj(
     cl::desc("WebAssembly Emscripten-style setjmp/longjmp handling"),
     cl::init(false));
 
+// A command-line option to keep implicit locals
+// for the purpose of testing with lit/llc ONLY.
+// This produces output which is not valid WebAssembly, and is not supported
+// by assemblers/disassemblers and other MC based tools.
+static cl::opt<bool> WasmDisableExplicitLocals(
+    "wasm-disable-explicit-locals", cl::Hidden,
+    cl::desc("WebAssembly: output implicit locals in"
+             " instruction output for test purposes only."),
+    cl::init(false));
+
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeWebAssemblyTarget() {
   // Register the target.
   RegisterTargetMachine<WebAssemblyTargetMachine> X(
@@ -75,6 +85,7 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeWebAssemblyTarget() {
   initializeWebAssemblyExplicitLocalsPass(PR);
   initializeWebAssemblyLowerBrUnlessPass(PR);
   initializeWebAssemblyRegNumberingPass(PR);
+  initializeWebAssemblyDebugFixupPass(PR);
   initializeWebAssemblyPeepholePass(PR);
 }
 
@@ -467,7 +478,8 @@ void WebAssemblyPassConfig::addPreEmitPass() {
   addPass(createWebAssemblyCFGStackify());
 
   // Insert explicit local.get and local.set operators.
-  addPass(createWebAssemblyExplicitLocals());
+  if (!WasmDisableExplicitLocals)
+    addPass(createWebAssemblyExplicitLocals());
 
   // Lower br_unless into br_if.
   addPass(createWebAssemblyLowerBrUnless());
@@ -478,6 +490,10 @@ void WebAssemblyPassConfig::addPreEmitPass() {
 
   // Create a mapping from LLVM CodeGen virtual registers to wasm registers.
   addPass(createWebAssemblyRegNumbering());
+
+  // Fix debug_values whose defs have been stackified.
+  if (!WasmDisableExplicitLocals)
+    addPass(createWebAssemblyDebugFixup());
 }
 
 yaml::MachineFunctionInfo *