[SPIRV] Emit DebugScope in wrapper (microsoft#7341) (microsoft#7529)

Legalization and optimization will produce inaccurate NS100 debug info
if there is no DebugScope emitted in the wrapper function. This PR
corrects this oversight and renames the wrapper to "__dxc_setup". This
may cause a stack frame named __dxc_setup to appear in an HLSL debugger,
however, users should be familiar with this type of thing. A C debugger
might show crt0, or a debugger can filter this frame out of the user's
view. This PR addresses
[7341](https://github.com/microsoft/DirectXShaderCompiler/issues//7341)

Author: SteveUrquhart

tools/clang/lib/SPIRV/EmitVisitor.cpp

@@ -1635,12 +1635,6 @@ bool EmitVisitor::visit(SpirvDebugLexicalBlock *inst) {
 }
 
 bool EmitVisitor::visit(SpirvDebugScope *inst) {
-  // Technically entry function wrappers do not exist in HLSL. They
-  // are just created by DXC. We do not want to emit DebugScope for
-  // it.
-  if (inEntryFunctionWrapper)
-    return true;
-
   initInstruction(inst);
   curInst.push_back(inst->getResultTypeId());
   curInst.push_back(getOrAssignResultId<SpirvInstruction>(inst));

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -14050,8 +14050,8 @@ bool SpirvEmitter::processTessellationShaderAttributes(
 }
 
 bool SpirvEmitter::emitEntryFunctionWrapperForRayTracing(
-    const FunctionDecl *decl, SpirvDebugFunction *debugFunction,
-    SpirvFunction *entryFuncInstr) {
+    const FunctionDecl *decl, RichDebugInfo **info,
+    SpirvDebugFunction *debugFunction, SpirvFunction *entryFuncInstr) {
   // The entry basic block.
   auto *entryLabel = spvBuilder.createBasicBlock();
   spvBuilder.setInsertPoint(entryLabel);
@@ -14160,6 +14160,10 @@ bool SpirvEmitter::emitEntryFunctionWrapperForRayTracing(
   spvBuilder.createReturn(decl->getBody()->getLocEnd());
   spvBuilder.endFunction();
 
+  if (spirvOptions.debugInfoRich && decl->hasBody()) {
+    spvContext.popDebugLexicalScope(*info);
+  }
+
   return true;
 }
 
@@ -14374,7 +14378,9 @@ SpirvFunction *SpirvEmitter::emitEntryFunctionWrapper(
       astContext.VoidTy, decl->getLocStart(), decl->getName());
 
   if (spirvOptions.debugInfoRich && decl->hasBody()) {
-    *debugFunction = emitDebugFunction(decl, entryFunction, info, "wrapper");
+    *debugFunction =
+        emitDebugFunction(decl, entryFunction, info, "__dxc_setup");
+    spvContext.pushDebugLexicalScope(*info, *debugFunction);
   }
 
   // Specify that entryFunction is an entry function wrapper.
@@ -14391,7 +14397,7 @@ SpirvFunction *SpirvEmitter::emitEntryFunctionWrapper(
   entryInfo->entryFunction = entryFunction;
 
   if (spvContext.isRay()) {
-    return emitEntryFunctionWrapperForRayTracing(decl, *debugFunction,
+    return emitEntryFunctionWrapperForRayTracing(decl, info, *debugFunction,
                                                  entryFuncInstr)
                ? entryFunction
                : nullptr;
@@ -14632,6 +14638,10 @@ SpirvFunction *SpirvEmitter::emitEntryFunctionWrapper(
   if (spvContext.isHS())
     doDecl(patchConstFunc);
 
+  if (spirvOptions.debugInfoRich && decl->hasBody()) {
+    spvContext.popDebugLexicalScope(*info);
+  }
+
   return entryFunction;
 }
 

tools/clang/lib/SPIRV/SpirvEmitter.h

@@ -958,6 +958,7 @@ class SpirvEmitter : public ASTConsumer {
   /// The wrapper function is also responsible for initializing global static
   /// variables for some cases.
   bool emitEntryFunctionWrapperForRayTracing(const FunctionDecl *entryFunction,
+                                             RichDebugInfo **info,
                                              SpirvDebugFunction *debugFunction,
                                              SpirvFunction *entryFuncId);
 

tools/clang/test/CodeGenSPIRV/rich.debug.function.param.hlsl

@@ -9,7 +9,7 @@
 // CHECK:               [[x:%[0-9]+]] = OpString "x"
 // CHECK:     [[srcMainName:%[0-9]+]] = OpString "main"
 // CHECK:           [[color:%[0-9]+]] = OpString "color"
-// CHECK:        [[mainName:%[0-9]+]] = OpString "wrapper"
+// CHECK:        [[mainName:%[0-9]+]] = OpString "__dxc_setup"
 
 // CHECK: [[int:%[0-9]+]] = OpExtInst %void [[set]] DebugTypeBasic {{%[0-9]+}} %uint_32 Signed
 // CHECK: [[float:%[0-9]+]] = OpExtInst %void [[set]] DebugTypeBasic {{%[0-9]+}} %uint_32 Float

tools/clang/test/CodeGenSPIRV/shader.debug.function.hlsl

@@ -6,7 +6,7 @@
 // CHECK:         [[fooName:%[0-9]+]] = OpString "foo"
 // CHECK:        [[emptyStr:%[0-9]+]] = OpString ""
 // CHECK:     [[srcMainName:%[0-9]+]] = OpString "main"
-// CHECK:        [[mainName:%[0-9]+]] = OpString "wrapper"
+// CHECK:        [[mainName:%[0-9]+]] = OpString "__dxc_setup"
 // CHECK:          [[clOpts:%[0-9]+]] = OpString " -E main -T ps_6_0 -spirv -fcgl -fspv-debug=vulkan
 
 // CHECK:    [[int:%[0-9]+]] = OpExtInst %void [[set]] DebugTypeBasic {{%[0-9]+}} %uint_32 %uint_4 %uint_0