From 27cac9536ccbba20d1c0580aa9e62416e06441e8 Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Tue, 7 Jul 2015 00:49:35 +0000
Subject: [PATCH] Debug info: Emit distinct __block_literal_generic types for
 blocks with different function signatures. (Previously clang would emit all
 block pointer types with the type of the first block pointer in the compile
 unit.)

rdar://problem/21602473

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241534 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGDebugInfo.cpp     | 12 ++++++------
 lib/CodeGen/CGDebugInfo.h       |  1 -
 test/CodeGen/debug-info-block.c | 27 ++++++++++++++++++++++-----
 3 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 959c80632a..ca02313bf5 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -705,9 +705,6 @@ llvm::DIType *CGDebugInfo::getOrCreateStructPtrType(StringRef Name,
 
 llvm::DIType *CGDebugInfo::CreateType(const BlockPointerType *Ty,
                                       llvm::DIFile *Unit) {
-  if (BlockLiteralGeneric)
-    return BlockLiteralGeneric;
-
   SmallVector<llvm::Metadata *, 8> EltTys;
   QualType FType;
   uint64_t FieldSize, FieldOffset;
@@ -753,12 +750,15 @@ llvm::DIType *CGDebugInfo::CreateType(const BlockPointerType *Ty,
   FieldOffset += FieldSize;
   Elements = DBuilder.getOrCreateArray(EltTys);
 
+  // The __block_literal_generic structs are marked with a special
+  // DW_AT_APPLE_BLOCK attribute and are an implementation detail only
+  // the debugger needs to know about. To allow type uniquing, emit
+  // them without a name or a location.
   EltTy =
-      DBuilder.createStructType(Unit, "__block_literal_generic", nullptr, LineNo,
+      DBuilder.createStructType(Unit, "", nullptr, LineNo,
                                 FieldOffset, 0, Flags, nullptr, Elements);
 
-  BlockLiteralGeneric = DBuilder.createPointerType(EltTy, Size);
-  return BlockLiteralGeneric;
+  return DBuilder.createPointerType(EltTy, Size);
 }
 
 llvm::DIType *CGDebugInfo::CreateType(const TemplateSpecializationType *Ty,
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index 10d3b0d9ab..d4a5bc80ca 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -65,7 +65,6 @@ class CGDebugInfo {
   llvm::DIType *OCLImage2dArrayDITy = nullptr;
   llvm::DIType *OCLImage3dDITy = nullptr;
   llvm::DIType *OCLEventDITy = nullptr;
-  llvm::DIType *BlockLiteralGeneric = nullptr;
 
   /// \brief Cache of previously constructed Types.
   llvm::DenseMap<const void *, llvm::TrackingMDRef> TypeCache;
diff --git a/test/CodeGen/debug-info-block.c b/test/CodeGen/debug-info-block.c
index 697ed9ce7d..48a9f66877 100644
--- a/test/CodeGen/debug-info-block.c
+++ b/test/CodeGen/debug-info-block.c
@@ -2,11 +2,28 @@
 // Verify that the desired debugging type is generated for a structure
 // member that is a pointer to a block.
 
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "__block_literal_generic"
-// CHECK-NOT: line
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, scope
+// CHECK-NOT:              line
+// CHECK-SAME:             elements: ![[ELEMS1:.*]])
+// CHECK: ![[ELEMS1]] = {{.*, .*, .*,}} ![[FPEL1:.*]], {{.*}}
+// CHECK: ![[INT:.*]] = !DIBasicType(name: "int"
+// CHECK: ![[FPEL1]] = {{.*}}"__FuncPtr", {{.*}}, baseType: ![[FPTY1:[0-9]+]]
+// CHECK: ![[FPTY1]] = {{.*}}baseType: ![[FNTY1:[0-9]+]]
+// CHECK: ![[FNTY1]] = !DISubroutineType(types: ![[VOIDVOID:[0-9]+]])
+// CHECK: ![[VOIDVOID]] = !{null, null}
 // CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "__block_descriptor"
-// CHECK-NOT: line
+// CHECK-NOT:              line
+// CHECK-SAME:            )
+
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, scope
+// CHECK-NOT:              line
+// CHECK-SAME:             elements: ![[ELEMS2:.*]])
+// CHECK: ![[ELEMS2]] = {{.*,.*,.*}}, ![[FPEL2:.*]], {{.*}}
+// CHECK: ![[FPEL2]] = {{.*}}"__FuncPtr", {{.*}}, baseType: ![[FPTY2:[0-9]+]]
+// CHECK: ![[FPTY2]] = {{.*}}baseType: ![[FNTY2:[0-9]+]]
+// CHECK: ![[FNTY2]] = !DISubroutineType(types: ![[INTINT:[0-9]+]])
+// CHECK: ![[INTINT]] = !{![[INT]], ![[INT]]}
 struct inStruct {
-  void (^genericBlockPtr)();
+  void (^voidBlockPtr)();
+  int (^intBlockPtr)(int);
 } is;
-
-- 
2.40.0