Revert "This patch causes clang to reject alias attributes that point to undefined...

This reverts commit r193161.

It broke

void foo() __attribute__((alias("bar")));
void bar() {}
void zed() __attribute__((alias("foo")));

Looks like we have to fix pr17639 first :-(

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193162 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 08240d1568cad6b5d9043272249908db4cbc7f0a..415c4b29633a84d5ef211811e57d3673bfbe6e3d 100644 (file)
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2015,8 +2015,6 @@ def err_attribute_weakref_without_alias : Error<
   "weakref declaration of '%0' must also have an alias attribute">;
 def err_alias_not_supported_on_darwin : Error <
   "only weak aliases are supported on darwin">;
-def err_alias_to_undefined : Error<
-  "alias must point to a defined variable or function">;
 def warn_attribute_wrong_decl_type : Warning<
   "%0 attribute only applies to %select{functions|unions|"
   "variables and functions|functions and methods|parameters|"

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 2311e084b72ab8ff32794f03b6dfdb7a72d70e71..567444253c9af3975f4bf995184a674c6257d237 100644 (file)
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -929,8 +929,9 @@ static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
   ///   to a replaceable global allocation function.
   ///
   /// We model such elidable calls with the 'builtin' attribute.
+  llvm::Function *Fn = dyn_cast<llvm::Function>(CalleeAddr);
   if (Callee->isReplaceableGlobalAllocationFunction() &&
-      !Callee->hasAttr<AliasAttr>()) {
+      Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
     // FIXME: Add addAttribute to CallSite.
     if (llvm::CallInst *CI = dyn_cast<llvm::CallInst>(CallOrInvoke))
       CI->addAttribute(llvm::AttributeSet::FunctionIndex,

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 2939b4a3d2ce026e20c061e2f9668471fc5c31aa..96ae437ff46f948d2ba251bd313e81a8c3bd0eda 100644 (file)
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -37,7 +37,6 @@
 #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"
@@ -934,12 +933,6 @@ 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
@@ -1105,7 +1098,7 @@ 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 scheduleAliasDefinitionEmission(GD);
+    return EmitAliasDefinition(GD);
 
   // If this is CUDA, be selective about which declarations we emit.
   if (LangOpts.CUDA) {
@@ -2082,24 +2075,6 @@ 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>();
@@ -2125,18 +2100,6 @@ 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(),

diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index d2dc8358eaff9ce09987c70a85d44df843d5c19c..066009ca7df81aa5f85abecb948129f6d8aaa177 100644 (file)
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -1024,7 +1024,6 @@ private:
 
   void EmitGlobalFunctionDefinition(GlobalDecl GD);
   void EmitGlobalVarDefinition(const VarDecl *D);
-  void scheduleAliasDefinitionEmission(GlobalDecl GD);
   void EmitAliasDefinition(GlobalDecl GD);
   void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);
   void EmitObjCIvarInitializations(ObjCImplementationDecl *D);

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index a08abd9efcf94fb6ebd52d3ebc03de5ed246298c..a71d3c0d7b5aebf527f55db99c71338b7cee51f7 100644 (file)
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -5020,13 +5020,6 @@ void Sema::DeclApplyPragmaWeak(Scope *S, NamedDecl *ND, WeakInfo &W) {
   W.setUsed(true);
   if (W.getAlias()) { // clone decl, impersonate __attribute(weak,alias(...))
     IdentifierInfo *NDId = ND->getIdentifier();
-
-    // FIXME: we should reject this (pr17640).
-    NamedDecl *Aliasee = LookupSingleName(TUScope, W.getAlias(),
-                                          W.getLocation(), LookupOrdinaryName);
-    if (Aliasee && Aliasee->hasAttr<AliasAttr>())
-      return;
-
     NamedDecl *NewD = DeclClonePragmaWeak(ND, W.getAlias(), W.getLocation());
     NewD->addAttr(::new (Context) AliasAttr(W.getLocation(), Context,
                                             NDId->getName()));

diff --git a/test/Sema/attr-alias-elf.c b/test/Sema/attr-alias-elf.c
deleted file mode 100644 (file)
index 32e4102..0000000
--- a/test/Sema/attr-alias-elf.c
+++ /dev/null
@@ -1,22 +0,0 @@
-// RUN: %clang_cc1 -triple x86_64-pc-linux  -fsyntax-only -verify -emit-llvm-only %s
-
-void f1(void) __attribute__((alias("g1")));
-void g1(void) {
-}
-
-void f2(void) __attribute__((alias("g2"))); // expected-error {{alias must point to a defined variable or function}}
-
-
-void f3(void) __attribute__((alias("g3"))); // expected-error {{alias must point to a defined variable or function}}
-void g3(void);
-
-extern int a1 __attribute__((alias("b1")));
-int b1 = 42;
-
-extern int a2 __attribute__((alias("b2"))); // expected-error {{alias must point to a defined variable or function}}
-
-extern int a3 __attribute__((alias("b3"))); // expected-error {{alias must point to a defined variable or function}}
-extern int b3;
-
-extern int a4 __attribute__((alias("b4"))); // expected-error {{alias must point to a defined variable or function}}
-typedef int b4;