nicolas/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

This patch causes clang to reject alias attributes that point to undefined

Browse Source 
names. For example, with this patch we now reject

void f1(void) __attribute__((alias("g1")));

This patch is implemented in CodeGen. It is quiet a bit simpler and more
compatible with gcc than implementing it in Sema. The downside is that the
errors only fire during -emit-llvm.

llvm-svn: 193161
This commit is contained in:
Rafael Espindola
2013-10-22 13:51:06 +00:00
parent acf49f31b6
commit 0fad0d7724
6 changed files with 71 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
clang/lib/CodeGen/CodeGenModule.cpp
View File

@@ -37,6 +37,7 @@
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/Version.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "clang/Sema/SemaDiagnostic.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/CallingConv.h"
@@ -933,6 +934,12 @@ void CodeGenModule::EmitDeferred() {
GlobalDecl D = DeferredDeclsToEmit.back();
DeferredDeclsToEmit.pop_back();
const ValueDecl *Global = cast<ValueDecl>(D.getDecl());
if (Global->hasAttr<AliasAttr>()) {
EmitAliasDefinition(D);
continue;
}
// Check to see if we've already emitted this. This is necessary
// for a couple of reasons: first, decls can end up in the
// deferred-decls queue multiple times, and second, decls can end
@@ -1098,7 +1105,7 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
// If this is an alias definition (which otherwise looks like a declaration)
// emit it now.
if (Global->hasAttr<AliasAttr>())
return EmitAliasDefinition(GD);
return scheduleAliasDefinitionEmission(GD);
// If this is CUDA, be selective about which declarations we emit.
if (LangOpts.CUDA) {
@@ -2075,6 +2082,24 @@ void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
AddGlobalAnnotations(D, Fn);
}
void CodeGenModule::scheduleAliasDefinitionEmission(GlobalDecl GD) {
const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
const AliasAttr *AA = D->getAttr<AliasAttr>();
assert(AA && "Not an alias?");
// Schedule it.
DeferredDeclsToEmit.push_back(GD);
llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
// Cause the aliasee emission to be scheduled.
if (isa<llvm::FunctionType>(DeclTy))
GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, /*ForVTable=*/false);
else
GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy), 0);
}
void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
const AliasAttr *AA = D->getAttr<AliasAttr>();
@@ -2100,6 +2125,18 @@ void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
llvm::PointerType::getUnqual(DeclTy), 0);
llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Aliasee);
if (!GV) {
llvm::ConstantExpr *CE = cast<llvm::ConstantExpr>(Aliasee);
assert(CE->getOpcode() == llvm::Instruction::BitCast ||
CE->getOpcode() == llvm::Instruction::GetElementPtr);
GV = cast<llvm::GlobalValue>(CE->getOperand(0));
}
if (GV->isDeclaration()) {
getDiags().Report(AA->getLocation(), diag::err_alias_to_undefined);
return;
}
// Create the new alias itself, but don't set a name yet.
llvm::GlobalValue *GA =
new llvm::GlobalAlias(Aliasee->getType(),