[clang] [llvm] [Clang][OpenMP] Support for dispatch construct (Sema & Codegen) support (PR #131838)

[via cfe-commits]

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@@ -4529,6 +4529,191 @@ void CodeGenFunction::EmitOMPMasterDirective(const OMPMasterDirective &S) {
   emitMaster(*this, S);
 }
 
+static Expr *replaceWithNewTraitsOrDirectCall(CapturedDecl *CDecl,
+                                              Expr *NewExpr) {
+  Expr *CurrentCallExpr = nullptr;
+  Stmt *CallExprStmt = CDecl->getBody();
+
+  if (BinaryOperator *BinaryCopyOpr = dyn_cast<BinaryOperator>(CallExprStmt)) {
+    CurrentCallExpr = BinaryCopyOpr->getRHS();
+    BinaryCopyOpr->setRHS(NewExpr);
+  } else {
+    CurrentCallExpr = dyn_cast<Expr>(CallExprStmt);
+    CDecl->setBody(NewExpr);
+  }
+
+  return CurrentCallExpr;
+}
+
+static Expr *transformCallInStmt(Stmt *StmtP, bool NoContext = false) {
+  Expr *CurrentExpr = nullptr;
+  if (auto *CptStmt = dyn_cast<CapturedStmt>(StmtP)) {
+    CapturedDecl *CDecl = CptStmt->getCapturedDecl();
+
+    CallExpr *NewCallExpr = nullptr;
+    for (const auto *attr : CDecl->attrs()) {
+      if (NoContext) {
+        if (const auto *annotateAttr =
+                llvm::dyn_cast<clang::AnnotateAttr>(attr);
+            annotateAttr && annotateAttr->getAnnotation() == "NoContextAttr") {
+          NewCallExpr = llvm::dyn_cast<CallExpr>(*annotateAttr->args_begin());
+        }
+      } else {
+        if (const auto *annotateAttr =
+                llvm::dyn_cast<clang::AnnotateAttr>(attr);
+            annotateAttr && annotateAttr->getAnnotation() == "NoVariantsAttr") {
+          NewCallExpr = llvm::dyn_cast<CallExpr>(*annotateAttr->args_begin());
+        }
+      }
+    }
+
+    CurrentExpr = replaceWithNewTraitsOrDirectCall(CDecl, NewCallExpr);
+  }
+  return CurrentExpr;
+}
+
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SunilKuravinakop wrote:

Can you please clarify your comment based on my following points?
1) There is a pre-computed call trait stored in AnnotateAttr. I am using those AnnotateAttrs in `transformCallInStmt`. In `replaceWithNewTraitsOrDirectCall` I am trying to set the call based on BinaryExpr under the dispatch directive.  
2) If you want me to pre-compute and store it in Sema I will have to clone the CDecl and store it. Earlier, in the helper functions (in Sema), I created new AST attributes, but according to your suggestion now I will have to store it in AnnotateAttr. 
3) An OpaqueValueExpr node copies the pointer of the SourceExpr. This does not help in noting the alternative call trait.

https://github.com/llvm/llvm-project/pull/131838