Commit 3d210ed3 authored by Amy Huang's avatar Amy Huang
Browse files

Revert "Allow system header to provide their own implementation of some builtin" 

This reverts commit 921f871a because it
causes libc++ code to trigger __warn_memset_zero_len.

See https://reviews.llvm.org/D71082.
parent 7ce2de2c

clang/include/clang/AST/Decl.h

+0 −3
Original line number Diff line number Diff line
@@ -2309,9 +2309,6 @@ public: 
  /// true through IsAligned.

  bool isReplaceableGlobalAllocationFunction(bool *IsAligned = nullptr) const;



  /// Determine if this function provides an inline implementation of a builtin.

  bool isInlineBuiltinDeclaration() const;



  /// Determine whether this is a destroying operator delete.

  bool isDestroyingOperatorDelete() const;

clang/lib/AST/Decl.cpp

+0 −8
Original line number Diff line number Diff line
@@ -3046,14 +3046,6 @@ bool FunctionDecl::isReplaceableGlobalAllocationFunction(bool *IsAligned) const 
  return Params == FPT->getNumParams();

}



bool FunctionDecl::isInlineBuiltinDeclaration() const {

  if (!getBuiltinID())

    return false;



  const FunctionDecl *Definition;

  return hasBody(Definition) && Definition->isInlineSpecified();

}



bool FunctionDecl::isDestroyingOperatorDelete() const {

  // C++ P0722:

  //   Within a class C, a single object deallocation function with signature

clang/lib/CodeGen/CGExpr.cpp

+1 −8
Original line number Diff line number Diff line
@@ -4621,14 +4621,7 @@ RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E, 
}



static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {



  if (auto builtinID = FD->getBuiltinID()) {

    // 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);

  }

clang/lib/CodeGen/CodeGenModule.cpp

+0 −5
Original line number Diff line number Diff line
@@ -1840,11 +1840,6 @@ void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F, 
  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.

clang/test/CodeGen/memcpy-nobuiltin.c

deleted100644 → 0
+0 −15
Original line number Diff line number Diff line 
// RUN: %clang_cc1 -verify -S -emit-llvm -o- %s -isystem %S -DWITH_DECL | FileCheck --check-prefix=CHECK-WITH-DECL %s

// RUN: %clang_cc1 -verify -S -emit-llvm -o- %s -isystem %S -UWITH_DECL | FileCheck --check-prefix=CHECK-NO-DECL %s

// RUN: %clang_cc1 -verify -S -emit-llvm -o- %s -isystem %S -DWITH_SELF_REFERENCE_DECL | FileCheck --check-prefix=CHECK-SELF-REF-DECL %s

//

// CHECK-WITH-DECL-NOT: @llvm.memcpy

// CHECK-NO-DECL: @llvm.memcpy

// CHECK-SELF-REF-DECL: @llvm.memcpy

//

#include <memcpy-nobuiltin.inc>

void test(void *dest, void const *from, size_t n) {

  memcpy(dest, from, n);



  static char buffer[1];

  memcpy(buffer, from, 2); // expected-warning {{'memcpy' will always overflow; destination buffer has size 1, but size argument is 2}}

}