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

[Justin Bogner via llvm-commits]

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@@ -318,22 +313,39 @@ static void translateMetadata(Module &M, const DXILResourceMap &DRM,
   // See https://github.com/llvm/llvm-project/issues/57928
   MDTuple *Signatures = nullptr;
 
-  if (MMDI.ShaderProfile == Triple::EnvironmentType::Library)
+  if (MMDI.ShaderProfile == Triple::EnvironmentType::Library) {
+    // Create a consolidated shader flag mask of all functions in the library
+    // to be used as shader flags mask value associated with top-level library
+    // entry metadata.
+    uint64_t ConsolidatedMask = ShaderFlags.ModuleFlags;
+    for (const auto &FunFlags : ShaderFlags.FuncShaderFlagsVec) {
+      ConsolidatedMask |= FunFlags.second;
+    }
     EntryFnMDNodes.emplace_back(
-        emitTopLevelLibraryNode(M, ResourceMD, ShaderFlags));
-  else if (MMDI.EntryPropertyVec.size() > 1) {
+        emitTopLevelLibraryNode(M, ResourceMD, ConsolidatedMask));
+  } else if (MMDI.EntryPropertyVec.size() > 1) {
     M.getContext().diagnose(DiagnosticInfoTranslateMD(
         M, "Non-library shader: One and only one entry expected"));
   }
 
   for (const EntryProperties &EntryProp : MMDI.EntryPropertyVec) {
-    // FIXME: ShaderFlagsAnalysis pass needs to collect and provide
-    // ShaderFlags for each entry function. For now, assume shader flags value
-    // of entry functions being compiled for lib_* shader profile viz.,
-    // EntryPro.Entry is 0.
-    uint64_t EntryShaderFlags =
-        (MMDI.ShaderProfile == Triple::EnvironmentType::Library) ? 0
-                                                                 : ShaderFlags;
+    Expected<const ComputedShaderFlags &> ECSF =
+        ShaderFlags.getShaderFlagsMask(EntryProp.Entry);
+    if (Error E = ECSF.takeError()) {
+      M.getContext().diagnose(DiagnosticInfoTranslateMD(
+          M, "Shader Flags information of Function '" +
+                 Twine(EntryProp.Entry->getName()) + "' not found"));
+    }
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bogner wrote:

If we're going to completely ignore the error here it would make more sense to simply have `getShaderFlagsMask` return `nullptr` if it fails. Using `Expected` to return a string that says "not found" is kind of heavy handed anyways.

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