[llvm] r185872 - Stop emitting weak symbols into the "coal" sections.

Bill Wendling isanbard at gmail.com
Mon Jul 8 14:34:52 PDT 2013


Author: void
Date: Mon Jul  8 16:34:52 2013
New Revision: 185872

URL: http://llvm.org/viewvc/llvm-project?rev=185872&view=rev
Log:
Stop emitting weak symbols into the "coal" sections.

The Mach-O linker has been able to support the weak-def bit on any symbol for
quite a while now. The compiler however continued to place these symbols into a
"coal" section, which required the linker to map them back to the base section
name.

Replace the sections like this:

  __TEXT/__textcoal_nt   instead use  __TEXT/__text
  __TEXT/__const_coal    instead use  __TEXT/__const
  __DATA/__datacoal_nt   instead use  __DATA/__data

<rdar://problem/14265330>

Added:
    llvm/trunk/test/CodeGen/X86/no-coal-sections.ll
Modified:
    llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
    llvm/trunk/test/CodeGen/X86/global-sections.ll

Modified: llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp?rev=185872&r1=185871&r2=185872&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp (original)
+++ llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp Mon Jul  8 16:34:52 2013
@@ -524,14 +524,14 @@ const MCSection *TargetLoweringObjectFil
 SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
                        Mangler *Mang, const TargetMachine &TM) const {
   if (Kind.isText())
-    return GV->isWeakForLinker() ? TextCoalSection : TextSection;
-
-  // If this is weak/linkonce, put this in a coalescable section, either in text
-  // or data depending on if it is writable.
+    return TextSection;
+ 
+  // If this is weak/linkonce, put this in a read only or data section depending
+  // on whether or not it's writable.
   if (GV->isWeakForLinker()) {
     if (Kind.isReadOnly())
-      return ConstTextCoalSection;
-    return DataCoalSection;
+      return ReadOnlySection;
+    return DataSection;
   }
 
   // FIXME: Alignment check should be handled by section classifier.

Modified: llvm/trunk/test/CodeGen/X86/global-sections.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/global-sections.ll?rev=185872&r1=185871&r2=185872&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/global-sections.ll (original)
+++ llvm/trunk/test/CodeGen/X86/global-sections.ll Mon Jul  8 16:34:52 2013
@@ -20,7 +20,7 @@
 
 ; TODO: linux drops this into .rodata, we drop it into ".gnu.linkonce.r.G2"
 
-; DARWIN: .section __TEXT,__const_coal,coalesced
+; DARWIN: .section __TEXT,__const
 ; DARWIN: _G2:
 ; DARWIN:    .long 42
 
@@ -70,7 +70,6 @@
 ; LINUX: .weak	foo_20_bar
 ; LINUX: foo_20_bar:
 
-; DARWIN: .section		__DATA,__datacoal_nt,coalesced
 ; DARWIN: .globl	"_foo bar"
 ; DARWIN:	.weak_definition "_foo bar"
 ; DARWIN: "_foo bar":
@@ -85,7 +84,7 @@
 ; LINUX:   .byte	1
 ; LINUX:   .size	G6, 1
 
-; DARWIN:  .section __TEXT,__const_coal,coalesced
+; DARWIN:  .section __TEXT,__const
 ; DARWIN:  .globl _G6
 ; DARWIN:  .weak_definition _G6
 ; DARWIN:_G6:
@@ -131,7 +130,7 @@
 @G10 = weak global [100 x i32] zeroinitializer, align 32 ; <[100 x i32]*> [#uses=0]
 
 
-; DARWIN: 	.section	__DATA,__datacoal_nt,coalesced
+; DARWIN: 	.section	__DATA,__data
 ; DARWIN: .globl _G10
 ; DARWIN:	.weak_definition _G10
 ; DARWIN:	.align	5

Added: llvm/trunk/test/CodeGen/X86/no-coal-sections.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/no-coal-sections.ll?rev=185872&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/no-coal-sections.ll (added)
+++ llvm/trunk/test/CodeGen/X86/no-coal-sections.ll Mon Jul  8 16:34:52 2013
@@ -0,0 +1,74 @@
+; RUN: llc < %s -mtriple x86_64-apple-macosx10 | FileCheck %s
+; <rdar://problem/14265330>
+
+; CHECK:     .section __TEXT,__text
+; CHECK-NOT: .section __TEXT,__textcoal_nt
+; CHECK:     .globl __ZN6TrickyIiLi0EEC1Ev
+
+; CHECK:     .section __DATA,__data
+; CHECK-NOT: .section __DATA,__datacoal_nt
+; CHECK:     .globl __ZTV6TrickyIiLi0EE
+
+; CHECK:     .section __TEXT,__const
+; CHECK-NOT: .section __TEXT,__const_coal
+; CHECK:     .globl __ZTS6TrickyIiLi0EE
+
+; CHECK:     .section __DATA,__data
+; CHECK-NOT: .section __DATA,__datacoal_nt
+; CHECK:     .globl __ZTI6TrickyIiLi0EE
+
+%class.Tricky = type { i32 (...)**, %union.anon }
+%union.anon = type { i32 }
+
+ at _ZTV6TrickyIiLi0EE = linkonce_odr unnamed_addr constant [4 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @_ZTI6TrickyIiLi0EE to i8*), i8* bitcast (void (%class.Tricky*)* @_ZN6TrickyIiLi0EED1Ev to i8*), i8* bitcast (void (%class.Tricky*)* @_ZN6TrickyIiLi0EED0Ev to i8*)]
+ at _ZTVN10__cxxabiv117__class_type_infoE = external global i8*
+ at _ZTS6TrickyIiLi0EE = linkonce_odr constant [15 x i8] c"6TrickyIiLi0EE\00"
+ at _ZTI6TrickyIiLi0EE = linkonce_odr unnamed_addr constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([15 x i8]* @_ZTS6TrickyIiLi0EE, i32 0, i32 0) }
+
+; Function Attrs: nounwind ssp uwtable
+define i32 @main() {
+entry:
+  %ok = alloca %class.Tricky, align 8
+  call void @_ZN6TrickyIiLi0EEC1Ev(%class.Tricky* %ok)
+  ret i32 0
+}
+
+; Function Attrs: inlinehint nounwind ssp uwtable
+define linkonce_odr void @_ZN6TrickyIiLi0EEC1Ev(%class.Tricky* nocapture %this) unnamed_addr align 2 {
+entry:
+  tail call void @_ZN6TrickyIiLi0EEC2Ev(%class.Tricky* %this)
+  ret void
+}
+
+; Function Attrs: nounwind readnone ssp uwtable
+define linkonce_odr void @_ZN6TrickyIiLi0EED1Ev(%class.Tricky* nocapture %this) unnamed_addr align 2 {
+entry:
+  ret void
+}
+
+; Function Attrs: nounwind readnone ssp uwtable
+define linkonce_odr void @_ZN6TrickyIiLi0EED2Ev(%class.Tricky* nocapture %this) unnamed_addr align 2 {
+entry:
+  ret void
+}
+
+; Function Attrs: inlinehint nounwind ssp uwtable
+define linkonce_odr void @_ZN6TrickyIiLi0EEC2Ev(%class.Tricky* nocapture %this) unnamed_addr align 2 {
+entry:
+  %0 = getelementptr inbounds %class.Tricky* %this, i64 0, i32 0
+  store i32 (...)** bitcast (i8** getelementptr inbounds ([4 x i8*]* @_ZTV6TrickyIiLi0EE, i64 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
+  ret void
+}
+
+; Function Attrs: nounwind ssp uwtable
+define linkonce_odr void @_ZN6TrickyIiLi0EED0Ev(%class.Tricky* %this) unnamed_addr align 2 {
+invoke.cont:
+  %0 = bitcast %class.Tricky* %this to i8*
+  tail call void @_ZdlPv(i8* %0)
+  ret void
+}
+
+declare i32 @__gxx_personality_v0(...)
+
+; Function Attrs: nounwind
+declare void @_ZdlPv(i8*)





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