From: Chris Lattner <sabre@nondot.org>
Date: Wed, 14 Oct 2009 05:55:45 +0000 (+0000)
Subject: fix some cfstring related issues:
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=278b9f06933c385ffbccc15f8491787470cb4a1b;p=clang

fix some cfstring related issues:
1) -fwritable-string does affect the non-utf16 version of cfstrings
   just not the utf16 ones.
2) utf16 strings should always be marked constant, as the __TEXT segment
   is readonly.
3) The name of the global doesn't matter, remove it from TargetInfo.
4) Trust the asmprinter to drop cstrings into the right section, like llvmgcc does now.

This fixes rdar://7115750



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84077 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index 8ce85cf6bb..a1e0a17c88 100644
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -300,12 +300,6 @@ public:
 
   virtual bool useGlobalsForAutomaticVariables() const { return false; }
 
-  /// getUnicodeStringSymbolPrefix - Get the default symbol prefix to
-  /// use for string literals.
-  virtual const char *getUnicodeStringSymbolPrefix() const {
-    return ".str";
-  }
-
   /// getUnicodeStringSection - Return the section to use for unicode
   /// string literals, or 0 if no special section is used.
   virtual const char *getUnicodeStringSection() const {
@@ -318,14 +312,6 @@ public:
     return "__DATA,__cfstring";
   }
 
-  /// getCFStringDataSection - Return the section to use for the
-  /// constant string data associated with a CFString literal, or 0 if
-  /// no special section is used.
-  virtual const char *getCFStringDataSection() const {
-    return "__TEXT,__cstring,cstring_literals";
-  }
-
-
   /// isValidSectionSpecifier - This is an optional hook that targets can
   /// implement to perform semantic checking on attribute((section("foo")))
   /// specifiers.  In this case, "foo" is passed in to be checked.  If the
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 6e670c58c6..1d4d1235c9 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -197,10 +197,6 @@ public:
       this->TLSSupported = false;
     }
 
-  virtual const char *getUnicodeStringSymbolPrefix() const {
-    return "__utf16_string_";
-  }
-
   virtual const char *getUnicodeStringSection() const {
     return "__TEXT,__ustring";
   }
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 4c8ef58367..a7658e5e14 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1434,27 +1434,24 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   // String pointer.
   llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str());
 
-  const char *Sect, *Prefix;
-  bool isConstant;
+  const char *Sect = 0;
   llvm::GlobalValue::LinkageTypes Linkage;
+  bool isConstant;
   if (isUTF16) {
-    Prefix = getContext().Target.getUnicodeStringSymbolPrefix();
     Sect = getContext().Target.getUnicodeStringSection();
-    // FIXME: why do utf strings get "l" labels instead of "L" labels?
+    // FIXME: why do utf strings get "_" labels instead of "L" labels?
     Linkage = llvm::GlobalValue::InternalLinkage;
-    // FIXME: Why does GCC not set constant here?
-    isConstant = false;
+    // Note: -fwritable-strings doesn't make unicode CFStrings writable, but
+    // does make plain ascii ones writable.
+    isConstant = true;
   } else {
-    Prefix = ".str";
-    Sect = getContext().Target.getCFStringDataSection();
     Linkage = llvm::GlobalValue::PrivateLinkage;
-    // FIXME: -fwritable-strings should probably affect this, but we
-    // are following gcc here.
-    isConstant = true;
+    isConstant = !Features.WritableStrings;
   }
+  
   llvm::GlobalVariable *GV =
-    new llvm::GlobalVariable(getModule(), C->getType(), isConstant,
-                             Linkage, C, Prefix);
+    new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C,
+                             ".str");
   if (Sect)
     GV->setSection(Sect);
   if (isUTF16) {
diff --git a/test/CodeGen/darwin-string-literals.c b/test/CodeGen/darwin-string-literals.c
index 3be24b1bce..04e43a234d 100644
--- a/test/CodeGen/darwin-string-literals.c
+++ b/test/CodeGen/darwin-string-literals.c
@@ -1,14 +1,14 @@
 // RUN: clang-cc -triple i386-apple-darwin9 -emit-llvm %s -o - | FileCheck -check-prefix LSB %s &&
 
 // CHECK-LSB: @.str = private constant [8 x i8] c"string0\00"
-// CHECK-LSB: @.str1 = private constant [8 x i8] c"string1\00", section "__TEXT,__cstring,cstring_literals"
-// CHECK-LSB: @__utf16_string_ = internal global [36 x i8] c"h\00e\00l\00l\00o\00 \00\92! \00\03& \00\90! \00w\00o\00r\00l\00d\00\00\00", section "__TEXT,__ustring", align 2
+// CHECK-LSB: @.str1 = private constant [8 x i8] c"string1\00"
+// CHECK-LSB: @.str2 = internal constant [36 x i8] c"h\00e\00l\00l\00o\00 \00\92! \00\03& \00\90! \00w\00o\00r\00l\00d\00\00\00", section "__TEXT,__ustring", align 2
 
 // RUN: clang-cc -triple powerpc-apple-darwin9 -emit-llvm %s -o - | FileCheck -check-prefix MSB %s
 
 // CHECK-MSB: @.str = private constant [8 x i8] c"string0\00"
-// CHECK-MSB: @.str1 = private constant [8 x i8] c"string1\00", section "__TEXT,__cstring,cstring_literals"
-// CHECK-MSB: @__utf16_string_ = internal global [36 x i8] c"\00h\00e\00l\00l\00o\00 !\92\00 &\03\00 !\90\00 \00w\00o\00r\00l\00d\00\00", section "__TEXT,__ustring", align 2
+// CHECK-MSB: @.str1 = private constant [8 x i8] c"string1\00"
+// CHECK-MSB: @.str2 = internal constant [36 x i8] c"\00h\00e\00l\00l\00o\00 !\92\00 &\03\00 !\90\00 \00w\00o\00r\00l\00d\00\00", section "__TEXT,__ustring", align 2
 
 const char *g0 = "string0";
 const void *g1 = __builtin___CFStringMakeConstantString("string1");