[PATCH][darwin] revert to .weak_definition on darwin<10

[David Fang]

It seems I am not very good at attaching patches.
How does this look?

David

> Hi,
> 	On darwin8 and 9, -no-integrated-as fails to assemble with the system 
> assembler (Apple's GNU as, 1.38) on the .weak_def_can_be_hidden directive, 
> which use to emit .weak_definition.
>
> http://llvm.org/bugs/show_bug.cgi?id=18100
>
> 	Attached is a patch that brings back the old behavior for darwin<10, 
> which is applicable to both darwin8 and 9, PPC and X86. The more correct 
> thing to do is to characterize the non-integrated assembler being used and 
> decide behavior that way, but currently there's no good way to propagate that 
> information at runtime, so the assumed OS/tool version pairing is the next 
> best thing.
>
> Would this be acceptable?
>
> David
>
>

-- 
David Fang
http://www.csl.cornell.edu/~fang/
-------------- next part --------------
diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index 24e2145..1f42ce6 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -20,6 +20,7 @@
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/ADT/Triple.h"
 
 namespace llvm {
   class AsmPrinterHandler;
@@ -62,6 +63,10 @@ namespace llvm {
     ///
     TargetMachine &TM;
 
+    /// Triple information - computed once from TargetMachine
+    ///
+    const Triple Tr;
+
     /// Target Asm Printer information.
     ///
     const MCAsmInfo *MAI;
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 7422988..24a82e1 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -95,7 +95,8 @@ static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
 
 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
   : MachineFunctionPass(ID),
-    TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
+    TM(tm), Tr(Twine(getTargetTriple())),
+    MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
     OutContext(Streamer.getContext()),
     OutStreamer(Streamer),
     LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
@@ -232,7 +233,12 @@ void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
 
       bool CanBeHidden = false;
 
-      if (Linkage == GlobalValue::LinkOnceODRLinkage) {
+      // -no-integrated-as: 
+      // old system assembler doesn't understand .weak_def_can_be_hidden
+      // FIXME: this should really be a check on the assembler characteristics
+      // rather than OS version
+      if (Linkage == GlobalValue::LinkOnceODRLinkage &&
+          !(Tr.isMacOSX() && Tr.isMacOSXVersionLT(10, 6))) {
         if (GV->hasUnnamedAddr()) {
           CanBeHidden = true;
         } else {
diff --git a/test/CodeGen/PowerPC/weak_def_can_be_hidden.ll b/test/CodeGen/PowerPC/weak_def_can_be_hidden.ll
new file mode 100644
index 0000000..130d8fa
--- /dev/null
+++ b/test/CodeGen/PowerPC/weak_def_can_be_hidden.ll
@@ -0,0 +1,38 @@
+; taken from X86 version of the same test
+; RUN: llc -mtriple=powerpc-apple-darwin10 -O0 < %s | FileCheck %s
+; RUN: llc -mtriple=powerpc-apple-darwin9 -O0 < %s | FileCheck --check-prefix=CHECK-D89 %s
+; RUN: llc -mtriple=powerpc-apple-darwin8 -O0 < %s | FileCheck --check-prefix=CHECK-D89 %s
+
+ at v1 = linkonce_odr global i32 32
+; CHECK: .globl  _v1
+; CHECK: .weak_def_can_be_hidden _v1
+
+; CHECK-D89: .globl  _v1
+; CHECK-D89: .weak_definition _v1
+
+define i32 @f1() {
+  %x = load i32 * @v1
+  ret i32 %x
+}
+
+ at v2 = linkonce_odr global i32 32
+; CHECK: .globl  _v2
+; CHECK: .weak_definition _v2
+
+; CHECK-D89: .globl  _v2
+; CHECK-D89: .weak_definition _v2
+
+ at v3 = linkonce_odr unnamed_addr global i32 32
+; CHECK: .globl  _v3
+; CHECK: .weak_def_can_be_hidden _v3
+
+; CHECK-D89: .globl  _v3
+; CHECK-D89: .weak_definition _v3
+
+define i32* @f2() {
+  ret i32* @v2
+}
+
+define i32* @f3() {
+  ret i32* @v3
+}
diff --git a/test/CodeGen/X86/weak_def_can_be_hidden.ll b/test/CodeGen/X86/weak_def_can_be_hidden.ll
index f78f357..22aa135 100644
--- a/test/CodeGen/X86/weak_def_can_be_hidden.ll
+++ b/test/CodeGen/X86/weak_def_can_be_hidden.ll
@@ -1,9 +1,16 @@
-; RUN: llc -mtriple=x86_64-apple-darwin  -O0 < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-apple-darwin11 -O0 < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-apple-darwin10 -O0 < %s | FileCheck %s
+; RUN: llc -mtriple=x86_64-apple-darwin9 -O0 < %s | FileCheck --check-prefix=CHECK-D89 %s
+; RUN: llc -mtriple=i686-apple-darwin9 -O0 < %s | FileCheck --check-prefix=CHECK-D89 %s
+; RUN: llc -mtriple=i686-apple-darwin8 -O0 < %s | FileCheck --check-prefix=CHECK-D89 %s
 
 @v1 = linkonce_odr global i32 32
 ; CHECK: .globl  _v1
 ; CHECK: .weak_def_can_be_hidden _v1
 
+; CHECK-D89: .globl  _v1
+; CHECK-D89: .weak_definition _v1
+
 define i32 @f1() {
   %x = load i32 * @v1
   ret i32 %x
@@ -13,10 +20,16 @@ define i32 @f1() {
 ; CHECK: .globl  _v2
 ; CHECK: .weak_definition _v2
 
+; CHECK-D89: .globl  _v2
+; CHECK-D89: .weak_definition _v2
+
 @v3 = linkonce_odr unnamed_addr global i32 32
 ; CHECK: .globl  _v3
 ; CHECK: .weak_def_can_be_hidden _v3
 
+; CHECK-D89: .globl  _v3
+; CHECK-D89: .weak_definition _v3
+
 define i32* @f2() {
   ret i32* @v2
 }