[llvm] [DirectX] Infrastructure to collect shader flags for each function (PR #112967)

[S. Bharadwaj Yadavalli via llvm-commits]

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@@ -63,20 +106,64 @@ void ComputedShaderFlags::print(raw_ostream &OS) const {
   OS << ";\n";
 }
 
+/// Get the combined shader flag mask of all module functions.
+const ComputedShaderFlags DXILModuleShaderFlagsInfo::getCombinedFlags() const {
+  return CombinedSFMask;
+}
+
+/// Return the shader flags mask of the specified function Func, if one exists.
+/// else an error
+Expected<const ComputedShaderFlags &>
+DXILModuleShaderFlagsInfo::getShaderFlagsMask(const Function *Func) const {
+  std::pair<Function const *, ComputedShaderFlags> V{Func, {}};
+  const auto Iter = llvm::lower_bound(FunctionFlags, V);
+  if (Iter == FunctionFlags.end() || Iter->first != Func) {
+    return createStringError("Shader Flags information of Function '" +
+                             Func->getName() + "' not found");
+  }
+  return Iter->second;
+}
+
+//===----------------------------------------------------------------------===//
+// ShaderFlagsAnalysis and ShaderFlagsAnalysisPrinterPass
+
+// Provide an explicit template instantiation for the static ID.
 AnalysisKey ShaderFlagsAnalysis::Key;
 
-ComputedShaderFlags ShaderFlagsAnalysis::run(Module &M,
-                                             ModuleAnalysisManager &AM) {
-  return ComputedShaderFlags::computeFlags(M);
+DXILModuleShaderFlagsInfo ShaderFlagsAnalysis::run(Module &M,
+                                                   ModuleAnalysisManager &AM) {
+  DXILModuleShaderFlagsInfo MSFI(M);
+  return MSFI;
 }
 
 PreservedAnalyses ShaderFlagsAnalysisPrinter::run(Module &M,
                                                   ModuleAnalysisManager &AM) {
-  ComputedShaderFlags Flags = AM.getResult<ShaderFlagsAnalysis>(M);
-  Flags.print(OS);
+  DXILModuleShaderFlagsInfo FlagsInfo = AM.getResult<ShaderFlagsAnalysis>(M);
+  for (const auto &F : M.getFunctionList()) {
+    if (F.isDeclaration())
+      continue;
+    OS << "; Shader Flags mask for Function: " << F.getName() << "\n";
+    auto SFMask = FlagsInfo.getShaderFlagsMask(&F);
+    if (Error E = SFMask.takeError()) {
+      M.getContext().diagnose(
+          DiagnosticInfoShaderFlags(M, toString(std::move(E))));
+    }
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bharadwajy wrote:

> This should be done through a call to `llvm::handleAllErrors`. Something like:
> 
> This handles arrays of errors so that your function can return more than one error.

Deleted this error-handling code as a result of the assertion added in `getShaderFlagsmask()`. 

https://github.com/llvm/llvm-project/pull/112967