Give explicit sections for string constants used in NSStrings.

Without them they can be merged with non unnamed_addr constants during LTO.
The resulting constant is not unnamed_addr and goes in a different section,
which causes ld64 to crash.

A testcase that would crash before:

* file1.mm:
void g(id notification) {
  [notification valueForKey:@"name"];
}

* file2.cpp:
extern const char js_name_str[] = "name";

* file3.cpp
extern bool JS_GetProperty(const char *name);
extern const char js_name_str[];
bool js_ReportUncaughtException() { JS_GetProperty(js_name_str); }

run

clang file1.mm  -o file1.o -c -w -emit-llvm
clang file2.cpp -o file2.o -c -w -emit-llvm
clang file3.cpp -o file3.o -c -w

ld -dylib -o XUL file1.o file2.o file3.o -undefined dynamic_lookup.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199688 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 88e6e66f9c0b3821fa963f2ddfb3a8d2907a8309..12edab7cd67755287cb18eabb75a88be28038b6e 100644 (file)
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -2396,12 +2396,17 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   GV->setUnnamedAddr(true);
   // Don't enforce the target's minimum global alignment, since the only use
   // of the string is via this class initializer.
+  // FIXME: We set the section explicitly to avoid a bug in ld64 224.1. Without
+  // it LLVM can merge the string with a non unnamed_addr one during LTO. Doing
+  // that changes the section it ends in, which surprises ld64.
   if (isUTF16) {
     CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy);
     GV->setAlignment(Align.getQuantity());
+    GV->setSection("__TEXT,__ustring");
   } else {
     CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
     GV->setAlignment(Align.getQuantity());
+    GV->setSection("__TEXT,__cstring,cstring_literals");
   }
 
   // String.

diff --git a/test/CodeGen/cfstring.c b/test/CodeGen/cfstring.c
index 9d98b56e6b843296c5faf43d38d62e20c1986dbb..f73ffc60826820bef086bb8cd14a1708ffd14fd8 100644 (file)
--- a/test/CodeGen/cfstring.c
+++ b/test/CodeGen/cfstring.c
@@ -5,9 +5,9 @@
 //
 // RUN: %clang_cc1 -fwritable-strings -emit-llvm %s -o - | FileCheck %s
 //
-// CHECK: @.str = linker_private unnamed_addr constant [14 x i8] c"Hello, World!\00", align 1
-// CHECK: @.str1 = linker_private unnamed_addr constant [7 x i8] c"yo joe\00", align 1
-// CHECK: @.str3 = linker_private unnamed_addr constant [16 x i8] c"Goodbye, World!\00", align 1
+// CHECK: @.str = linker_private unnamed_addr constant [14 x i8] c"Hello, World!\00", section "__TEXT,__cstring,cstring_literals", align 1
+// CHECK: @.str1 = linker_private unnamed_addr constant [7 x i8] c"yo joe\00", section "__TEXT,__cstring,cstring_literals", align 1
+// CHECK: @.str3 = linker_private unnamed_addr constant [16 x i8] c"Goodbye, World!\00", section "__TEXT,__cstring,cstring_literals", align 1
 
 #define CFSTR __builtin___CFStringMakeConstantString
 

diff --git a/test/CodeGen/darwin-string-literals.c b/test/CodeGen/darwin-string-literals.c
index c7d9ff916000fcbe9f87c9150137b08de6e9fb7f..621a46eb36fe70f7b04d7d8012e4ce9199d6661c 100644 (file)
--- a/test/CodeGen/darwin-string-literals.c
+++ b/test/CodeGen/darwin-string-literals.c
@@ -2,16 +2,16 @@
 
 // CHECK-LSB: @.str = private unnamed_addr constant [8 x i8] c"string0\00"
 // CHECK-LSB: @.str1 = linker_private unnamed_addr constant [8 x i8] c"string1\00"
-// CHECK-LSB: @.str2 = internal unnamed_addr constant [18 x i16] [i16 104, i16 101, i16 108, i16 108, i16 111, i16 32, i16 8594, i16 32, i16 9731, i16 32, i16 8592, i16 32, i16 119, i16 111, i16 114, i16 108, i16 100, i16 0], align 2
-// CHECK-LSB: @.str4 = internal unnamed_addr constant [6 x i16] [i16 116, i16 101, i16 115, i16 116, i16 8482, i16 0], align 2
+// CHECK-LSB: @.str2 = internal unnamed_addr constant [18 x i16] [i16 104, i16 101, i16 108, i16 108, i16 111, i16 32, i16 8594, i16 32, i16 9731, i16 32, i16 8592, i16 32, i16 119, i16 111, i16 114, i16 108, i16 100, i16 0], section "__TEXT,__ustring", align 2
+// CHECK-LSB: @.str4 = internal unnamed_addr constant [6 x i16] [i16 116, i16 101, i16 115, i16 116, i16 8482, i16 0], section "__TEXT,__ustring", align 2
 
 
 // RUN: %clang_cc1 -triple powerpc-apple-darwin9 -emit-llvm %s -o - | FileCheck -check-prefix CHECK-MSB %s
 
 // CHECK-MSB: @.str = private unnamed_addr constant [8 x i8] c"string0\00"
 // CHECK-MSB: @.str1 = linker_private unnamed_addr constant [8 x i8] c"string1\00"
-// CHECK-MSB: @.str2 = internal unnamed_addr constant [18 x i16] [i16 104, i16 101, i16 108, i16 108, i16 111, i16 32, i16 8594, i16 32, i16 9731, i16 32, i16 8592, i16 32, i16 119, i16 111, i16 114, i16 108, i16 100, i16 0], align 2
-// CHECK-MSB: @.str4 = internal unnamed_addr constant [6 x i16] [i16 116, i16 101, i16 115, i16 116, i16 8482, i16 0], align 2
+// CHECK-MSB: @.str2 = internal unnamed_addr constant [18 x i16] [i16 104, i16 101, i16 108, i16 108, i16 111, i16 32, i16 8594, i16 32, i16 9731, i16 32, i16 8592, i16 32, i16 119, i16 111, i16 114, i16 108, i16 100, i16 0], section "__TEXT,__ustring", align 2
+// CHECK-MSB: @.str4 = internal unnamed_addr constant [6 x i16] [i16 116, i16 101, i16 115, i16 116, i16 8482, i16 0], section "__TEXT,__ustring", align 2
 
 const char *g0 = "string0";
 const void *g1 = __builtin___CFStringMakeConstantString("string1");

diff --git a/test/CodeGen/utf16-cfstrings.c b/test/CodeGen/utf16-cfstrings.c
index d4f214b0d644a8776ea1df82326ba1a0aa959fc6..3ac84b353732024741d495fa42cf3dde27b6cf5c 100644 (file)
--- a/test/CodeGen/utf16-cfstrings.c
+++ b/test/CodeGen/utf16-cfstrings.c
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm %s -o - | FileCheck %s
 // <rdar://problem/10655949>
 
-// CHECK: @.str = internal unnamed_addr constant [9 x i16] [i16 252, i16 98, i16 101, i16 114, i16 104, i16 117, i16 110, i16 100, i16 0], align 2
+// CHECK: @.str = internal unnamed_addr constant [9 x i16] [i16 252, i16 98, i16 101, i16 114, i16 104, i16 117, i16 110, i16 100, i16 0], section "__TEXT,__ustring", align 2
 
 #define CFSTR __builtin___CFStringMakeConstantString
 

diff --git a/test/CodeGenObjC/2009-08-05-utf16.m b/test/CodeGenObjC/2009-08-05-utf16.m
index 06458e730ae2a873ae24d91dae70785d6874e0cd..76927c08e2513c851c9512897beacae9e4ccf379 100644 (file)
--- a/test/CodeGenObjC/2009-08-05-utf16.m
+++ b/test/CodeGenObjC/2009-08-05-utf16.m
@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 -emit-llvm -w -x objective-c %s -o - | FileCheck %s
 // rdar://7095855 rdar://7115749
 
-// CHECK: internal unnamed_addr constant [6 x i16] [i16 105, i16 80, i16 111, i16 100, i16 8482, i16 0], align 2
+// CHECK: internal unnamed_addr constant [6 x i16] [i16 105, i16 80, i16 111, i16 100, i16 8482, i16 0], section "__TEXT,__ustring", align 2
 void *P = @"iPod™";

diff --git a/test/CodeGenObjC/2010-02-01-utf16-with-null.m b/test/CodeGenObjC/2010-02-01-utf16-with-null.m
index 284548000702755588cfe7e75b72445733630678..f40552a8ad8eef29c8012a7428fca8ca18a92745 100644 (file)
--- a/test/CodeGenObjC/2010-02-01-utf16-with-null.m
+++ b/test/CodeGenObjC/2010-02-01-utf16-with-null.m
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -triple i686-apple-darwin -emit-llvm %s -o - | FileCheck %s
 // rdar://7589850
 
-// CHECK: @.str = internal unnamed_addr constant [9 x i16] [i16 103, i16 111, i16 111, i16 100, i16 0, i16 98, i16 121, i16 101, i16 0], align 2
+// CHECK: @.str = internal unnamed_addr constant [9 x i16] [i16 103, i16 111, i16 111, i16 100, i16 0, i16 98, i16 121, i16 101, i16 0], section "__TEXT,__ustring", align 2
 // CHECK: @_unnamed_cfstring_ = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 2000, i8* bitcast ([9 x i16]* @.str to i8*), i32 8 }, section "__DATA,__cfstring"
 // CHECK: @P = global i8* bitcast (%struct.NSConstantString* @_unnamed_cfstring_ to i8*), align 4
 void *P = @"good\0bye";

diff --git a/test/CodeGenObjC/constant-strings.m b/test/CodeGenObjC/constant-strings.m
index cad634a4b10395bf489591e5e146be84e692352c..0a65496373580fc80f084c47d7259a17699f7764 100644 (file)
--- a/test/CodeGenObjC/constant-strings.m
+++ b/test/CodeGenObjC/constant-strings.m
@@ -3,7 +3,7 @@
 
 // Check that we set alignment 1 on the string.
 //
-// CHECK-NEXT: @.str = {{.*}}constant [13 x i8] c"Hello World!\00", align 1
+// CHECK-NEXT: @.str = {{.*}}constant [13 x i8] c"Hello World!\00", section "__TEXT,__cstring,cstring_literals", align 1
 
 // RUN: %clang_cc1 -fobjc-runtime=gcc -emit-llvm -o %t %s
 // RUN: FileCheck --check-prefix=CHECK-GNU < %t %s