Reapply Allow system header to provide their own implementation of some builtin
This reverts commit 3d210ed3d1880c615776b07d1916edb400c245a6.
See https://reviews.llvm.org/D71082 for the patch and discussion that make it
possible to reapply this patch.
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index b23d9df..8e06041 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -4621,8 +4621,15 @@
}
static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
+
if (auto builtinID = FD->getBuiltinID()) {
- return CGCallee::forBuiltin(builtinID, FD);
+ // Replaceable builtin provide their own implementation of a builtin. Unless
+ // we are in the builtin implementation itself, don't call the actual
+ // builtin. If we are in the builtin implementation, avoid trivial infinite
+ // recursion.
+ if (!FD->isInlineBuiltinDeclaration() ||
+ CGF.CurFn->getName() == FD->getName())
+ return CGCallee::forBuiltin(builtinID, FD);
}
llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index e347f3b..4b9d56e 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1840,6 +1840,11 @@
else if (const auto *SA = FD->getAttr<SectionAttr>())
F->setSection(SA->getName());
+ if (FD->isInlineBuiltinDeclaration()) {
+ F->addAttribute(llvm::AttributeList::FunctionIndex,
+ llvm::Attribute::NoBuiltin);
+ }
+
if (FD->isReplaceableGlobalAllocationFunction()) {
// A replaceable global allocation function does not act like a builtin by
// default, only if it is invoked by a new-expression or delete-expression.