commit 34771b594ca8cdf8cd2e40b27170efa4ed2833c5
author Daniel Dunbar <daniel@zuster.org> Mon Sep 14 04:33:21 2009 +0000
committer Daniel Dunbar <daniel@zuster.org> Mon Sep 14 04:33:21 2009 +0000
tree 59529dd83c3bbeffdf83247e1579f581157202dc
parent b0d58196808aba4b3d1a7488bd5566f3c0a83e89

Fix subtle bug in generating LLVM function declarations for builtin functions.

The decl wasn't being passed down, which meant that function attributes were not
being set correctly. This is particularly important for ARM, since it wants to
override the calling convention. Instead we would emit the builtin with the
wrong calling convention, and instcombine would come along and merrily shred all
the calls to it. :)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@81756 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGBuiltin.cpp

diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 77c408a..e049cc8 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -556,7 +556,7 @@
   // that function.
   if (getContext().BuiltinInfo.isLibFunction(BuiltinID) ||
       getContext().BuiltinInfo.isPredefinedLibFunction(BuiltinID))
-    return EmitCall(CGM.getBuiltinLibFunction(BuiltinID),
+    return EmitCall(CGM.getBuiltinLibFunction(FD, BuiltinID),
                     E->getCallee()->getType(), E->arg_begin(),
                     E->arg_end());
 

lib/CodeGen/CodeGenModule.cpp

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 05f1468..fca6ebe 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1256,7 +1256,8 @@
 
 /// getBuiltinLibFunction - Given a builtin id for a function like
 /// "__builtin_fabsf", return a Function* for "fabsf".
-llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) {
+llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD,
+                                                  unsigned BuiltinID) {
   assert((Context.BuiltinInfo.isLibFunction(BuiltinID) ||
           Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) &&
          "isn't a lib fn");
@@ -1276,8 +1277,7 @@
 
   // Unique the name through the identifier table.
   Name = getContext().Idents.get(Name).getName();
-  // FIXME: param attributes for sext/zext etc.
-  return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
+  return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD));
 }
 
 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys,

lib/CodeGen/CodeGenModule.h

diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index f115feb..ff8ffb3 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -303,7 +303,8 @@
 
   /// getBuiltinLibFunction - Given a builtin id for a function like
   /// "__builtin_fabsf", return a Function* for "fabsf".
-  llvm::Value *getBuiltinLibFunction(unsigned BuiltinID);
+  llvm::Value *getBuiltinLibFunction(const FunctionDecl *FD,
+                                     unsigned BuiltinID);
 
   llvm::Function *getMemCpyFn();
   llvm::Function *getMemMoveFn();

test/CodeGen/builtin-attributes.c

diff --git a/test/CodeGen/builtin-attributes.c b/test/CodeGen/builtin-attributes.c
new file mode 100644
index 0000000..184e967
--- /dev/null
+++ b/test/CodeGen/builtin-attributes.c
@@ -0,0 +1,12 @@
+// RUN: clang-cc -triple arm-unknown-unknown -emit-llvm -o - %s | FileCheck %s
+
+// CHECK: declare arm_aapcscc i32 @printf(i8*, ...)
+void f0() {
+  printf("a\n");
+}
+
+// CHECK: call arm_aapcscc void @exit
+// CHECK: unreachable
+void f1() {
+  exit(1);
+}