Use the new method for specifying garbage collection metadata in the module.

The garbage collection metadata needs to be merged "intelligently", when two or
more modules are linked together, and not merely appended. (Appending creates a
section which is too large.) The module flags metadata method is the way to do
this.
<rdar://problem/8198537>

llvm-svn: 150648

4 files changed, 52 insertions, 30 deletions

diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index edef754b158..b4896920b49 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -3568,33 +3568,48 @@ enum ImageInfoFlags {
 
 void CGObjCCommonMac::EmitImageInfo() {
   unsigned version = 0; // Version is unused?
-  unsigned flags = 0;
-
-  // FIXME: Fix and continue?
-  if (CGM.getLangOptions().getGC() != LangOptions::NonGC)
-    flags |= eImageInfo_GarbageCollected;
-  if (CGM.getLangOptions().getGC() == LangOptions::GCOnly)
-    flags |= eImageInfo_GCOnly;
-
-  // We never allow @synthesize of a superclass property.
-  flags |= eImageInfo_CorrectedSynthesize;
-
-  // Emitted as int[2];
-  uint32_t Values[2] = { version, flags };
-
-  const char *Section;
-  if (ObjCABI == 1)
-    Section = "__OBJC, __image_info,regular";
-  else
-    Section = "__DATA, __objc_imageinfo, regular, no_dead_strip";
-  llvm::GlobalVariable *GV =
-    CreateMetadataVar("\01L_OBJC_IMAGE_INFO",
-                      llvm::ConstantDataArray::get(VMContext, Values),
-                      Section, 0, true);
-  GV->setConstant(true);
+  const char *Section = (ObjCABI == 1) ?
+    "__OBJC, __image_info,regular" :
+    "__DATA, __objc_imageinfo, regular, no_dead_strip";
+
+  // Generate module-level named metadata to convey this information to the
+  // linker and code-gen.
+  llvm::Module &Mod = CGM.getModule();
+
+  // Add the ObjC ABI version to the module flags.
+  Mod.addModuleFlag(llvm::Module::Error, "Objective-C Version", ObjCABI);
+  Mod.addModuleFlag(llvm::Module::Error, "Objective-C Image Info Version",
+                    version);
+  Mod.addModuleFlag(llvm::Module::Error, "Objective-C Image Info Section",
+                    llvm::MDString::get(VMContext,Section));
+
+  if (CGM.getLangOptions().getGC() == LangOptions::NonGC) {
+    // Non-GC overrides those files which specify GC.
+    Mod.addModuleFlag(llvm::Module::Override,
+                      "Objective-C Garbage Collection", (uint32_t)0);
+  } else {
+    // Add the ObjC garbage collection value.
+    Mod.addModuleFlag(llvm::Module::Error,
+                      "Objective-C Garbage Collection",
+                      eImageInfo_GarbageCollected);
+
+    if (CGM.getLangOptions().getGC() == LangOptions::GCOnly) {
+      // Add the ObjC GC Only value.
+      Mod.addModuleFlag(llvm::Module::Error, "Objective-C GC Only",
+                        eImageInfo_GCOnly);
+
+      // Require that GC be specified and set to eImageInfo_GarbageCollected.
+      llvm::Value *Ops[2] = {
+        llvm::MDString::get(VMContext, "Objective-C Garbage Collection"),
+        llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
+                               eImageInfo_GarbageCollected)
+      };
+      Mod.addModuleFlag(llvm::Module::Require, "Objective-C GC Only",
+                        llvm::MDNode::get(VMContext, Ops));
+    }
+  }
 }
 
-
 // struct objc_module {
 //   unsigned long version;
 //   unsigned long size;
diff --git a/clang/test/CodeGenObjC/debug-info-block-helper.m b/clang/test/CodeGenObjC/debug-info-block-helper.m
index 59086a568f2..8f88eb58a8b 100644
--- a/clang/test/CodeGenObjC/debug-info-block-helper.m
+++ b/clang/test/CodeGenObjC/debug-info-block-helper.m
@@ -2,7 +2,7 @@
 // RUN: %clang_cc1 -emit-llvm -fblocks -g -triple x86_64-apple-darwin10 -fobjc-fragile-abi %s -o - | FileCheck %s
 extern void foo(void(^)(void));
 
-// CHECK: !36 = metadata !{i32 {{.*}}, i32 0, metadata !6, metadata !"__destroy_helper_block_", metadata !"__destroy_helper_block_", metadata !"", metadata !6, i32 24, metadata !37, i1 true, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (i8*)* @__destroy_helper_block_, null, null, metadata !39} ; [ DW_TAG_subprogram ]
+// CHECK: !40 = metadata !{i32 {{.*}}, i32 0, metadata !10, metadata !"__destroy_helper_block_", metadata !"__destroy_helper_block_", metadata !"", metadata !10, i32 24, metadata !41, i1 true, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (i8*)* @__destroy_helper_block_, null, null, metadata !43} ; [ DW_TAG_subprogram ]
 
 @interface NSObject {
   struct objc_object *isa;
diff --git a/clang/test/CodeGenObjC/image-info.m b/clang/test/CodeGenObjC/image-info.m
index 22f7229b695..613b272bdea 100644
--- a/clang/test/CodeGenObjC/image-info.m
+++ b/clang/test/CodeGenObjC/image-info.m
@@ -4,5 +4,14 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o %t %s
 // RUN: FileCheck --check-prefix CHECK-NONFRAGILE < %t %s
 
-// CHECK-FRAGILE: @"\01L_OBJC_IMAGE_INFO" = internal constant [2 x i32] [i32 0, i32 16], section "__OBJC, __image_info,regular"
-// CHECK-NONFRAGILE: @"\01L_OBJC_IMAGE_INFO" = internal constant [2 x i32] [i32 0, i32 16], section "__DATA, __objc_imageinfo, regular, no_dead_strip"
+// CHECK-FRAGILE:      !llvm.module.flags = !{!0, !1, !2, !3}
+// CHECK-FRAGILE:      !0 = metadata !{i32 1, metadata !"Objective-C Version", i32 1}
+// CHECK-FRAGILE-NEXT: !1 = metadata !{i32 1, metadata !"Objective-C Image Info Version", i32 0}
+// CHECK-FRAGILE-NEXT: !2 = metadata !{i32 1, metadata !"Objective-C Image Info Section", metadata !"__OBJC, __image_info,regular"}
+// CHECK-FRAGILE-NEXT: !3 = metadata !{i32 4, metadata !"Objective-C Garbage Collection", i32 0}
+
+// CHECK-NONFRAGILE:      !llvm.module.flags = !{!0, !1, !2, !3}
+// CHECK-NONFRAGILE:      !0 = metadata !{i32 1, metadata !"Objective-C Version", i32 2}
+// CHECK-NONFRAGILE-NEXT: !1 = metadata !{i32 1, metadata !"Objective-C Image Info Version", i32 0}
+// CHECK-NONFRAGILE-NEXT: !2 = metadata !{i32 1, metadata !"Objective-C Image Info Section", metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip"}
+// CHECK-NONFRAGILE-NEXT: !3 = metadata !{i32 4, metadata !"Objective-C Garbage Collection", i32 0}
diff --git a/clang/test/CodeGenObjC/objc-align.m b/clang/test/CodeGenObjC/objc-align.m
index f07272516f1..f3c586eeb21 100644
--- a/clang/test/CodeGenObjC/objc-align.m
+++ b/clang/test/CodeGenObjC/objc-align.m
@@ -6,7 +6,6 @@
 // RUN: grep '@"\\01L_OBJC_CLASS_A" = internal global .*, section "__OBJC,__class,regular,no_dead_strip", align 4' %t
 // RUN: grep '@"\\01L_OBJC_CLASS_C" = internal global .*, section "__OBJC,__class,regular,no_dead_strip", align 4' %t
 // RUN: grep '@"\\01L_OBJC_CLASS_PROTOCOLS_C" = internal global .*, section "__OBJC,__cat_cls_meth,regular,no_dead_strip", align 4' %t
-// RUN: grep '@"\\01L_OBJC_IMAGE_INFO" = internal constant .*, section "__OBJC, __image_info,regular"' %t
 // RUN: grep '@"\\01L_OBJC_METACLASS_A" = internal global .*, section "__OBJC,__meta_class,regular,no_dead_strip", align 4' %t
 // RUN: grep '@"\\01L_OBJC_METACLASS_C" = internal global .*, section "__OBJC,__meta_class,regular,no_dead_strip", align 4' %t
 // RUN: grep '@"\\01L_OBJC_MODULES" = internal global .*, section "__OBJC,__module_info,regular,no_dead_strip", align 4' %t
@@ -20,7 +19,6 @@
 // RUNX: grep '@"OBJC_METACLASS_$_A" = global' %t &&
 // RUNX: grep '@"OBJC_METACLASS_$_C" = global' %t &&
 // RUNX: grep '@"\\01L_OBJC_CLASSLIST_REFERENCES_$_0" = internal global .*, section "__DATA, __objc_classrefs, regular, no_dead_strip", align 8' %t &&
-// RUNX: grep '@"\\01L_OBJC_IMAGE_INFO" = internal constant .*, section "__DATA, __objc_imageinfo, regular, no_dead_strip"' %t &&
 // RUNX: grep '@"\\01L_OBJC_LABEL_CATEGORY_$" = internal global .*, section "__DATA, __objc_catlist, regular, no_dead_strip", align 8' %t &&
 // RUNX: grep '@"\\01L_OBJC_LABEL_CLASS_$" = internal global .*, section "__DATA, __objc_classlist, regular, no_dead_strip", align 8' %t &&
 // RUNX: grep '@"\\01l_OBJC_$_CATEGORY_A_$_Cat" = internal global .*, section "__DATA, __objc_const", align 8' %t &&