Remove the linker_private and linker_private_weak linkages.

These linkages were introduced some time ago, but it was never very
clear what exactly their semantics were or what they should be used
for. Some investigation found these uses:

* utf-16 strings in clang.
* non-unnamed_addr strings produced by the sanitizers.

It turns out they were just working around a more fundamental problem.
For some sections a MachO linker needs a symbol in order to split the
section into atoms, and llvm had no idea that was the case. I fixed
that in r201700 and it is now safe to use the private linkage. When
the object ends up in a section that requires symbols, llvm will use a
'l' prefix instead of a 'L' prefix and things just work.

With that, these linkages were already dead, but there was a potential
future user in the objc metadata information. I am still looking at
CGObjcMac.cpp, but at this point I am convinced that linker_private
and linker_private_weak are not what they need.

The objc uses are currently split in

* Regular symbols (no '\01' prefix). LLVM already directly provides
whatever semantics they need.
* Uses of a private name (start with "\01L" or "\01l") and private
linkage. We can drop the "\01L" and "\01l" prefixes as soon as llvm
agrees with clang on L being ok or not for a given section. I have two
patches in code review for this.
* Uses of private name and weak linkage.

The last case is the one that one could think would fit one of these
linkages. That is not the case. The semantics are

* the linker will merge these symbol by *name*.
* the linker will hide them in the final DSO.

Given that the merging is done by name, any of the private (or
internal) linkages would be a bad match. They allow llvm to rename the
symbols, and that is really not what we want. From the llvm point of
view, these objects should really be (linkonce|weak)(_odr)?.

For now, just keeping the "\01l" prefix is probably the best for these
symbols. If we one day want to have a more direct support in llvm,
IMHO what we should add is not a linkage, it is just a hidden_symbol
attribute. It would be applicable to multiple linkages. For example,
on weak it would produce the current behavior we have for objc
metadata. On internal, it would be equivalent to private (and we
should then remove private).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203866 91177308-0d34-0410-b5e6-96231b3b80d8

13 files changed, 17 insertions, 80 deletions

diff --git a/test/Bitcode/linkage-types-3.2.ll b/test/Bitcode/linkage-types-3.2.ll
index 8bacb124ee..fd070efbd4 100644
--- a/test/Bitcode/linkage-types-3.2.ll
+++ b/test/Bitcode/linkage-types-3.2.ll
@@ -17,10 +17,10 @@
 ; CHECK: @private.var = private constant i32 0
 
 @linker_private.var = linker_private constant i32 0
-; CHECK: @linker_private.var = linker_private constant i32 0
+; CHECK: @linker_private.var = private constant i32 0
 
 @linker_private_weak.var = linker_private_weak constant i32 0
-; CHECK: @linker_private_weak.var = linker_private_weak constant i32 0
+; CHECK: @linker_private_weak.var = private constant i32 0
 
 @linker_private_weak_def_auto.var = linker_private_weak_def_auto constant i32 0
 ; CHECK: @linker_private_weak_def_auto.var = constant i32 0
@@ -59,13 +59,13 @@ define private void @private()
 }
 
 define linker_private void @linker_private()
-; CHECK: define linker_private void @linker_private
+; CHECK: define private void @linker_private
 {
   ret void;
 }
 
 define linker_private_weak void @linker_private_weak()
-; CHECK: define linker_private_weak void @linker_private_weak
+; CHECK: define private void @linker_private_weak
 {
   ret void;
 }
diff --git a/test/CodeGen/ARM/2009-08-23-linkerprivate.ll b/test/CodeGen/ARM/2009-08-23-linkerprivate.ll
deleted file mode 100644
index 392c70a9fd..0000000000
--- a/test/CodeGen/ARM/2009-08-23-linkerprivate.ll
+++ /dev/null
@@ -1,8 +0,0 @@
-; RUN: llc < %s -march=arm -mtriple=arm-apple-darwin | FileCheck %s
-
-; ModuleID = '/Volumes/MacOS9/tests/WebKit/JavaScriptCore/profiler/ProfilerServer.mm'
-
-@"\01l_objc_msgSend_fixup_alloc" = linker_private_weak hidden global i32 0, section "__DATA, __objc_msgrefs, coalesced", align 16
-
-; CHECK: .globl l_objc_msgSend_fixup_alloc
-; CHECK: .weak_definition l_objc_msgSend_fixup_alloc
diff --git a/test/CodeGen/ARM/2011-04-12-AlignBug.ll b/test/CodeGen/ARM/2011-04-12-AlignBug.ll
index 317be94e86..97297f78c7 100644
--- a/test/CodeGen/ARM/2011-04-12-AlignBug.ll
+++ b/test/CodeGen/ARM/2011-04-12-AlignBug.ll
@@ -3,9 +3,9 @@ target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-
 target triple = "thumbv7-apple-darwin10.0.0"
 
 ; CHECK: align 3
-@.v = linker_private unnamed_addr constant <4 x i32> <i32 1, i32 2, i32 3, i32 4>, align 8
+@.v = private unnamed_addr constant <4 x i32> <i32 1, i32 2, i32 3, i32 4>, align 8
 ; CHECK: align 2
-@.strA = linker_private unnamed_addr constant [4 x i8] c"bar\00"
+@.strA = private unnamed_addr constant [4 x i8] c"bar\00"
 ; CHECK-NOT: align
-@.strB = linker_private unnamed_addr constant [4 x i8] c"foo\00", align 1
-@.strC = linker_private unnamed_addr constant [4 x i8] c"baz\00", section "__TEXT,__cstring,cstring_literals", align 1
+@.strB = private unnamed_addr constant [4 x i8] c"foo\00", align 1
+@.strC = private unnamed_addr constant [4 x i8] c"baz\00", section "__TEXT,__cstring,cstring_literals", align 1
diff --git a/test/CodeGen/NVPTX/bug17709.ll b/test/CodeGen/NVPTX/bug17709.ll
index 92f0fcb11e..076c446845 100644
--- a/test/CodeGen/NVPTX/bug17709.ll
+++ b/test/CodeGen/NVPTX/bug17709.ll
@@ -4,7 +4,7 @@
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"
 target triple = "nvptx64-nvidia-cuda"
 
-define linker_private ptx_device { double, double } @__utils1_MOD_trace(%"struct.array2_complex(kind=8).43.5.57"* noalias %m) {
+define private ptx_device { double, double } @__utils1_MOD_trace(%"struct.array2_complex(kind=8).43.5.57"* noalias %m) {
 entry:
   ;unreachable
   %t0 = insertvalue {double, double} undef, double 1.0, 0
diff --git a/test/CodeGen/PowerPC/2009-08-23-linkerprivate.ll b/test/CodeGen/PowerPC/2009-08-23-linkerprivate.ll
deleted file mode 100644
index ae2acd43e9..0000000000
--- a/test/CodeGen/PowerPC/2009-08-23-linkerprivate.ll
+++ /dev/null
@@ -1,8 +0,0 @@
-; RUN: llc < %s -march=ppc32 -mtriple=powerpc-apple-darwin | FileCheck %s
-
-; ModuleID = '/Volumes/MacOS9/tests/WebKit/JavaScriptCore/profiler/ProfilerServer.mm'
-
-@"\01l_objc_msgSend_fixup_alloc" = linker_private_weak hidden global i32 0, section "__DATA, __objc_msgrefs, coalesced", align 16
-
-; CHECK: .globl l_objc_msgSend_fixup_alloc
-; CHECK: .weak_definition l_objc_msgSend_fixup_alloc
diff --git a/test/CodeGen/SPARC/exception.ll b/test/CodeGen/SPARC/exception.ll
index b45d998a9c..3a3f59f138 100644
--- a/test/CodeGen/SPARC/exception.ll
+++ b/test/CodeGen/SPARC/exception.ll
@@ -11,8 +11,8 @@
 
 @_ZTIi = external constant %struct.__fundamental_type_info_pseudo
 @_ZTIf = external constant %struct.__fundamental_type_info_pseudo
-@.cst = linker_private unnamed_addr constant [12 x i8] c"catched int\00", align 64
-@.cst1 = linker_private unnamed_addr constant [14 x i8] c"catched float\00", align 64
+@.cst = private unnamed_addr constant [12 x i8] c"catched int\00", align 64
+@.cst1 = private unnamed_addr constant [14 x i8] c"catched float\00", align 64
 
 ; V8ABS-LABEL: main:
 ; V8ABS:        .cfi_startproc
diff --git a/test/CodeGen/SPARC/setjmp.ll b/test/CodeGen/SPARC/setjmp.ll
index 39984fb14b..a31cd70167 100644
--- a/test/CodeGen/SPARC/setjmp.ll
+++ b/test/CodeGen/SPARC/setjmp.ll
@@ -7,7 +7,7 @@
 %struct.__jmp_buf_tag = type { [3 x i32], i32, %0 }
 
 @jenv = common unnamed_addr global %struct.jmpbuf_env* null
-@.cst = linker_private unnamed_addr constant [30 x i8] c"in bar with jmp_buf's id: %d\0A\00", align 64
+@.cst = private unnamed_addr constant [30 x i8] c"in bar with jmp_buf's id: %d\0A\00", align 64
 
 ; CHECK-LABEL: foo
 ; CHECK-DAG:   st {{.+}}, [%i0]
diff --git a/test/CodeGen/X86/2009-08-23-linkerprivate.ll b/test/CodeGen/X86/2009-08-23-linkerprivate.ll
deleted file mode 100644
index 90fac15442..0000000000
--- a/test/CodeGen/X86/2009-08-23-linkerprivate.ll
+++ /dev/null
@@ -1,8 +0,0 @@
-; RUN: llc < %s -march=x86 -mtriple=i686-apple-darwin | FileCheck %s
-
-; ModuleID = '/Volumes/MacOS9/tests/WebKit/JavaScriptCore/profiler/ProfilerServer.mm'
-
-@"\01l_objc_msgSend_fixup_alloc" = linker_private_weak hidden global i32 0, section "__DATA, __objc_msgrefs, coalesced", align 16
-
-; CHECK: .globl l_objc_msgSend_fixup_alloc
-; CHECK: .weak_definition l_objc_msgSend_fixup_alloc
diff --git a/test/CodeGen/X86/cfstring.ll b/test/CodeGen/X86/cfstring.ll
index 8cdd59e9ae..cae4320989 100644
--- a/test/CodeGen/X86/cfstring.ll
+++ b/test/CodeGen/X86/cfstring.ll
@@ -7,7 +7,7 @@
 ; Make sure that the string ends up the correct section.
 
 ; CHECK:        .section __TEXT,__cstring
-; CHECK-NEXT: l_.str3:
+; CHECK-NEXT: L_.str3:
 
 ; CHECK:        .section  __DATA,__cfstring
 ; CHECK-NEXT:   .align  4
@@ -15,13 +15,13 @@
 ; CHECK-NEXT:   .quad  ___CFConstantStringClassReference
 ; CHECK-NEXT:   .long  1992
 ; CHECK-NEXT:   .space  4
-; CHECK-NEXT:   .quad  l_.str3
+; CHECK-NEXT:   .quad  L_.str3
 ; CHECK-NEXT:   .long  0
 ; CHECK-NEXT:   .space  4
 
 @isLogVisible = global i8 0, align 1
 @__CFConstantStringClassReference = external global [0 x i32]
-@.str3 = linker_private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+@.str3 = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
 @_unnamed_cfstring_4 = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr inbounds ([1 x i8]* @.str3, i32 0, i32 0), i32 0 }, section "__DATA,__cfstring"
 @null.array = weak_odr constant [1 x i8] zeroinitializer, align 1
 
diff --git a/test/CodeGen/X86/linker-private.ll b/test/CodeGen/X86/linker-private.ll
deleted file mode 100644
index ecea34235d..0000000000
--- a/test/CodeGen/X86/linker-private.ll
+++ /dev/null
@@ -1,10 +0,0 @@
-; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck --check-prefix=ELF %s
-; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck --check-prefix=MACHO %s
-
-@foo = linker_private global i32 42
-;ELF: {{^}}.Lfoo:
-;MACHO: {{^}}l_foo:
-
-define i32* @f() {
-  ret i32* @foo
-}
diff --git a/test/Feature/linker_private_linkages.ll b/test/Feature/linker_private_linkages.ll
deleted file mode 100644
index 19bcbb40aa..0000000000
--- a/test/Feature/linker_private_linkages.ll
+++ /dev/null
@@ -1,6 +0,0 @@
-; RUN: llvm-as < %s | llvm-dis > %t1.ll
-; RUN: llvm-as %t1.ll -o - | llvm-dis > %t2.ll
-; RUN: diff %t1.ll %t2.ll
-
-@foo = linker_private hidden global i32 0
-@bar = linker_private_weak hidden global i32 0
diff --git a/test/Transforms/ConstantMerge/linker-private.ll b/test/Transforms/ConstantMerge/linker-private.ll
deleted file mode 100644
index eba7880e8a..0000000000
--- a/test/Transforms/ConstantMerge/linker-private.ll
+++ /dev/null
@@ -1,23 +0,0 @@
-; RUN: opt < %s -constmerge -S | FileCheck %s
-; <rdar://problem/10564621>
-
-%0 = type opaque
-%struct.NSConstantString = type { i32*, i32, i8*, i32 }
-
-; CHECK: @.str3 = linker_private unnamed_addr constant [1 x i8] zeroinitializer, align 1
-
-@isLogVisible = global i8 0, align 1
-@__CFConstantStringClassReference = external global [0 x i32]
-@.str3 = linker_private unnamed_addr constant [1 x i8] zeroinitializer, align 1
-@_unnamed_cfstring_4 = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr inbounds ([1 x i8]* @.str3, i32 0, i32 0), i32 0 }, section "__DATA,__cfstring"
-@null.array = weak_odr constant [1 x i8] zeroinitializer, align 1
-
-define linkonce_odr void @bar() nounwind ssp align 2 {
-entry:
-  %stack = alloca i8*, align 4
-  %call = call %0* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to %0* (i8*, i8*, %0*)*)(i8* null, i8* null, %0* bitcast (%struct.NSConstantString* @_unnamed_cfstring_4 to %0*))
-  store i8* getelementptr inbounds ([1 x i8]* @null.array, i32 0, i32 0), i8** %stack, align 4
-  ret void
-}
-
-declare i8* @objc_msgSend(i8*, i8*, ...) nonlazybind
diff --git a/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll b/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll
index 072861720e..79e300cb6b 100644
--- a/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll
+++ b/test/Transforms/ObjCARC/ensure-that-exception-unwind-path-is-visited.ll
@@ -24,11 +24,11 @@ target triple = "x86_64-apple-macosx10.9.0"
 @"\01L_OBJC_METH_VAR_NAME_" = internal global [4 x i8] c"new\00", section "__TEXT,__objc_methname,cstring_literals", align 1
 @"\01L_OBJC_SELECTOR_REFERENCES_" = internal global i8* getelementptr inbounds ([4 x i8]* @"\01L_OBJC_METH_VAR_NAME_", i64 0, i64 0), section "__DATA, __objc_selrefs, literal_pointers, no_dead_strip"
 @__CFConstantStringClassReference = external global [0 x i32]
-@.str = linker_private unnamed_addr constant [11 x i8] c"Failed: %@\00", align 1
+@.str = private unnamed_addr constant [11 x i8] c"Failed: %@\00", align 1
 @_unnamed_cfstring_ = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i64 10 }, section "__DATA,__cfstring"
 @"OBJC_CLASS_$_NSException" = external global %struct._class_t
 @"\01L_OBJC_CLASSLIST_REFERENCES_$_1" = internal global %struct._class_t* @"OBJC_CLASS_$_NSException", section "__DATA, __objc_classrefs, regular, no_dead_strip", align 8
-@.str2 = linker_private unnamed_addr constant [4 x i8] c"Foo\00", align 1
+@.str2 = private unnamed_addr constant [4 x i8] c"Foo\00", align 1
 @_unnamed_cfstring_3 = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr inbounds ([4 x i8]* @.str2, i32 0, i32 0), i64 3 }, section "__DATA,__cfstring"
 @"\01L_OBJC_METH_VAR_NAME_4" = internal global [14 x i8] c"raise:format:\00", section "__TEXT,__objc_methname,cstring_literals", align 1
 @"\01L_OBJC_SELECTOR_REFERENCES_5" = internal global i8* getelementptr inbounds ([14 x i8]* @"\01L_OBJC_METH_VAR_NAME_4", i64 0, i64 0), section "__DATA, __objc_selrefs, literal_pointers, no_dead_strip"