Unconditionally support block introspection data in a new field at the end

of the block descriptor field.  This field is the ObjC style @encode
signature of the implementation function, and was to this point
conditionally provided in the block literal data structure.  That
provisional support is removed.

Additionally, eliminate unused enumerations for the block literal flags field.
The first shipping ABI unconditionally set (1<<29) but this bit is unused
by the runtime, so the second ABI will unconditionally have (1<<30) set so
that the runtime can in fact distinguish whether the additional data is
present or not.

llvm-svn: 96989

7 files changed, 140 insertions, 59 deletions

diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index d909f83e74d..edff4847719 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -59,7 +59,6 @@ public:
   unsigned POSIXThreads      : 1; // Compiling with POSIX thread support
                                   // (-pthread)
   unsigned Blocks            : 1; // block extension to C
-  unsigned BlockIntrospection: 1; // block have ObjC type encodings.
   unsigned EmitAllDecls      : 1; // Emit all declarations, even if
                                   // they are unused.
   unsigned MathErrno         : 1; // Math functions must respect errno
@@ -143,7 +142,6 @@ public:
     ThreadsafeStatics = 1;
     POSIXThreads = 0;
     Blocks = 0;
-    BlockIntrospection = 0;
     EmitAllDecls = 0;
     MathErrno = 1;
 
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 4693e5c1433..1f5f154fb8f 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -235,7 +235,6 @@ def fastcp : Flag<"-fastcp">, Group<f_Group>;
 def fastf : Flag<"-fastf">, Group<f_Group>;
 def fast : Flag<"-fast">, Group<f_Group>;
 def fasynchronous_unwind_tables : Flag<"-fasynchronous-unwind-tables">, Group<f_Group>;
-def fblock_introspection : Flag<"-fblock-introspection">, Group<f_Group>;
 def fblocks : Flag<"-fblocks">, Group<f_Group>;
 def fbootclasspath_EQ : Joined<"-fbootclasspath=">, Group<f_Group>;
 def fbuiltin_strcat : Flag<"-fbuiltin-strcat">, Group<f_Group>;
diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp
index c6c5d5a230c..7076067e438 100644
--- a/clang/lib/CodeGen/CGBlocks.cpp
+++ b/clang/lib/CodeGen/CGBlocks.cpp
@@ -24,7 +24,7 @@ using namespace clang;
 using namespace CodeGen;
 
 llvm::Constant *CodeGenFunction::
-BuildDescriptorBlockDecl(bool BlockHasCopyDispose, CharUnits Size,
+BuildDescriptorBlockDecl(const BlockExpr *BE, bool BlockHasCopyDispose, CharUnits Size,
                          const llvm::StructType* Ty,
                          std::vector<HelperInfo> *NoteForHelper) {
   const llvm::Type *UnsignedLongTy
@@ -43,6 +43,7 @@ BuildDescriptorBlockDecl(bool BlockHasCopyDispose, CharUnits Size,
   C = llvm::ConstantInt::get(UnsignedLongTy, Size.getQuantity());
   Elts.push_back(C);
 
+  // optional copy/dispose helpers
   if (BlockHasCopyDispose) {
     // copy_func_helper_decl
     Elts.push_back(BuildCopyHelper(Ty, NoteForHelper));
@@ -51,6 +52,17 @@ BuildDescriptorBlockDecl(bool BlockHasCopyDispose, CharUnits Size,
     Elts.push_back(BuildDestroyHelper(Ty, NoteForHelper));
   }
 
+  // Signature.  non-optional ObjC-style method descriptor @encode sequence
+  std::string BlockTypeEncoding;
+  CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
+
+  Elts.push_back(llvm::ConstantExpr::getBitCast(
+          CGM.GetAddrOfConstantCString(BlockTypeEncoding), PtrToInt8Ty));
+  
+  // Layout.
+  C = llvm::ConstantInt::get(UnsignedLongTy, 0);
+  Elts.push_back(C);
+
   C = llvm::ConstantStruct::get(VMContext, Elts, false);
 
   C = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true,
@@ -135,30 +147,14 @@ llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
 
   size_t BlockFields = 5;
 
-  bool hasIntrospection  = CGM.getContext().getLangOptions().BlockIntrospection;
-
-  if (hasIntrospection) {
-    BlockFields++;
-  }
   std::vector<llvm::Constant*> Elts(BlockFields);
 
-  if (hasIntrospection) {
-    std::string BlockTypeEncoding;
-    CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
-
-    Elts[5] = llvm::ConstantExpr::getBitCast(
-            CGM.GetAddrOfConstantCString(BlockTypeEncoding), PtrToInt8Ty);
-  }
-
   llvm::Constant *C;
   llvm::Value *V;
 
   {
     // C = BuildBlockStructInitlist();
-    unsigned int flags = BLOCK_HAS_DESCRIPTOR;
-
-    if (hasIntrospection)
-      flags |= BLOCK_HAS_OBJC_TYPE;
+    unsigned int flags = BLOCK_HAS_OBJC_TYPE;
 
     // We run this first so that we set BlockHasCopyDispose from the entire
     // block literal.
@@ -199,7 +195,7 @@ llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
 
     if (subBlockDeclRefDecls.size() == 0) {
       // __descriptor
-      Elts[4] = BuildDescriptorBlockDecl(subBlockHasCopyDispose, subBlockSize,
+      Elts[4] = BuildDescriptorBlockDecl(BE, subBlockHasCopyDispose, subBlockSize,
                                          0, 0);
 
       // Optimize to being a global block.
@@ -221,8 +217,6 @@ llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
     for (int i=0; i<4; ++i)
       Types[i] = Elts[i]->getType();
     Types[4] = PtrToInt8Ty;
-    if (hasIntrospection)
-      Types[5] = PtrToInt8Ty;
 
     for (unsigned i=0; i < subBlockDeclRefDecls.size(); ++i) {
       const Expr *E = subBlockDeclRefDecls[i];
@@ -245,8 +239,6 @@ llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
 
     for (unsigned i=0; i<4; ++i)
       Builder.CreateStore(Elts[i], Builder.CreateStructGEP(V, i, "block.tmp"));
-    if (hasIntrospection)
-      Builder.CreateStore(Elts[5], Builder.CreateStructGEP(V, 5, "block.tmp"));
 
     for (unsigned i=0; i < subBlockDeclRefDecls.size(); ++i)
       {
@@ -335,7 +327,8 @@ llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
     NoteForHelper.resize(helpersize);
 
     // __descriptor
-    llvm::Value *Descriptor = BuildDescriptorBlockDecl(subBlockHasCopyDispose,
+    llvm::Value *Descriptor = BuildDescriptorBlockDecl(BE,
+                                                       subBlockHasCopyDispose,
                                                        subBlockSize, Ty,
                                                        &NoteForHelper);
     Descriptor = Builder.CreateBitCast(Descriptor, PtrToInt8Ty);
@@ -371,6 +364,16 @@ const llvm::Type *BlockModule::getBlockDescriptorType() {
   // struct __block_descriptor {
   //   unsigned long reserved;
   //   unsigned long block_size;
+  //
+  //   // later, the following will be added
+  //
+  //   struct {
+  //     void (*copyHelper)();
+  //     void (*copyHelper)();
+  //   } helpers;                // !!! optional
+  //
+  //   const char *signature;   // the block signature
+  //   const char *layout;      // reserved
   // };
   BlockDescriptorType = llvm::StructType::get(UnsignedLongTy->getContext(),
                                               UnsignedLongTy,
@@ -399,20 +402,8 @@ const llvm::Type *BlockModule::getGenericBlockLiteralType() {
   //   int __reserved;
   //   void (*__invoke)(void *);
   //   struct __block_descriptor *__descriptor;
-  //   // GNU runtime only:
-  //   const char *types;
   // };
-  if (CGM.getContext().getLangOptions().BlockIntrospection)
-    GenericBlockLiteralType = llvm::StructType::get(IntTy->getContext(),
-                                                  PtrToInt8Ty,
-                                                  IntTy,
-                                                  IntTy,
-                                                  PtrToInt8Ty,
-                                                  BlockDescPtrTy,
-                                                  PtrToInt8Ty,
-                                                  NULL);
-  else
-    GenericBlockLiteralType = llvm::StructType::get(IntTy->getContext(),
+  GenericBlockLiteralType = llvm::StructType::get(IntTy->getContext(),
                                                   PtrToInt8Ty,
                                                   IntTy,
                                                   IntTy,
@@ -556,7 +547,7 @@ BlockModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
   const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
     getTypes().ConvertType(getContext().IntTy));
 
-  llvm::Constant *DescriptorFields[2];
+  llvm::Constant *DescriptorFields[4];
 
   // Reserved
   DescriptorFields[0] = llvm::Constant::getNullValue(UnsignedLongTy);
@@ -567,9 +558,21 @@ BlockModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
     CGM.GetTargetTypeStoreSize(getGenericBlockLiteralType());
   DescriptorFields[1] =
     llvm::ConstantInt::get(UnsignedLongTy,BlockLiteralSize.getQuantity());
+  
+  // signature.  non-optional ObjC-style method descriptor @encode sequence
+  std::string BlockTypeEncoding;
+  CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
+
+  DescriptorFields[2] = llvm::ConstantExpr::getBitCast(
+          CGM.GetAddrOfConstantCString(BlockTypeEncoding), PtrToInt8Ty);
+  
+  // layout
+  DescriptorFields[3] =
+    llvm::ConstantInt::get(UnsignedLongTy,0);
 
+  // build the structure from the 4 elements
   llvm::Constant *DescriptorStruct =
-    llvm::ConstantStruct::get(VMContext, &DescriptorFields[0], 2, false);
+    llvm::ConstantStruct::get(VMContext, &DescriptorFields[0], 4, false);
 
   llvm::GlobalVariable *Descriptor =
     new llvm::GlobalVariable(getModule(), DescriptorStruct->getType(), true,
@@ -578,8 +581,6 @@ BlockModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
 
   int FieldCount = 5;
   // Generate the constants for the block literal.
-  if (CGM.getContext().getLangOptions().BlockIntrospection)
-    FieldCount = 6;
 
   std::vector<llvm::Constant*> LiteralFields(FieldCount);
 
@@ -602,10 +603,8 @@ BlockModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
   LiteralFields[0] = getNSConcreteGlobalBlock();
 
   // Flags
-  LiteralFields[1] = CGM.getContext().getLangOptions().BlockIntrospection ?
-    llvm::ConstantInt::get(IntTy, BLOCK_IS_GLOBAL | BLOCK_HAS_DESCRIPTOR |
-            BLOCK_HAS_OBJC_TYPE) :
-    llvm::ConstantInt::get(IntTy, BLOCK_IS_GLOBAL | BLOCK_HAS_DESCRIPTOR);
+  LiteralFields[1] =
+    llvm::ConstantInt::get(IntTy, BLOCK_IS_GLOBAL | BLOCK_HAS_OBJC_TYPE);
 
   // Reserved
   LiteralFields[2] = llvm::Constant::getNullValue(IntTy);
@@ -616,14 +615,6 @@ BlockModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
   // Descriptor
   LiteralFields[4] = Descriptor;
   
-  // Type encoding
-  if (CGM.getContext().getLangOptions().BlockIntrospection) {
-    std::string BlockTypeEncoding;
-    CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
-
-    LiteralFields[5] = CGM.GetAddrOfConstantCString(BlockTypeEncoding);
-  }
-
   llvm::Constant *BlockLiteralStruct =
     llvm::ConstantStruct::get(VMContext, LiteralFields, false);
 
diff --git a/clang/lib/CodeGen/CGBlocks.h b/clang/lib/CodeGen/CGBlocks.h
index fc18c7cc564..39f26f8b136 100644
--- a/clang/lib/CodeGen/CGBlocks.h
+++ b/clang/lib/CodeGen/CGBlocks.h
@@ -54,7 +54,6 @@ public:
         BLOCK_HAS_COPY_DISPOSE =  (1 << 25),
         BLOCK_HAS_CXX_OBJ =       (1 << 26),
         BLOCK_IS_GLOBAL =         (1 << 28),
-        BLOCK_HAS_DESCRIPTOR =    (1 << 29),
         BLOCK_HAS_OBJC_TYPE  =    (1 << 30)
     };
 };
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index c4f0a9fcfff..64d5cbdb01a 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -465,7 +465,8 @@ public:
   //===--------------------------------------------------------------------===//
 
   llvm::Value *BuildBlockLiteralTmp(const BlockExpr *);
-  llvm::Constant *BuildDescriptorBlockDecl(bool BlockHasCopyDispose,
+  llvm::Constant *BuildDescriptorBlockDecl(const BlockExpr *,
+                                           bool BlockHasCopyDispose,
                                            CharUnits Size,
                                            const llvm::StructType *,
                                            std::vector<HelperInfo> *);
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index d2391b391cd..145e29e7979 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1011,7 +1011,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   // -fblocks=0 is default.
   if (Args.hasFlag(options::OPT_fblocks, options::OPT_fno_blocks,
                    getToolChain().IsBlocksDefault())) {
-    Args.AddLastArg(CmdArgs, options::OPT_fblock_introspection);
     CmdArgs.push_back("-fblocks");
   }
 
diff --git a/clang/test/CodeGen/blocksignature.c b/clang/test/CodeGen/blocksignature.c
new file mode 100644
index 00000000000..141693f9e4d
--- /dev/null
+++ b/clang/test/CodeGen/blocksignature.c
@@ -0,0 +1,94 @@
+// RUN: %clang_cc1 -fblocks -triple x86_64-apple-darwin9 %s -emit-llvm -o - | FileCheck %s -check-prefix=X64
+// RUN: %clang_cc1 -fblocks -triple i686-apple-darwin9 %s -emit-llvm -o - | FileCheck %s -check-prefix=X32
+
+// X64: @.str = private constant [6 x i8] c"v8@?0\00" 
+// X64: @__block_literal_global = internal constant %1 { i8** @_NSConcreteGlobalBlock, i32 1342177280,
+// X64: @.str1 = private constant [12 x i8] c"i16@?0c8f12\00"
+// X64:   store i32 1073741824, i32* %block.tmp2
+
+// X32: @.str = private constant [6 x i8] c"v4@?0\00" 
+// X32: @__block_literal_global = internal constant %1 { i8** @_NSConcreteGlobalBlock, i32 1342177280,
+// X32: @.str1 = private constant [11 x i8] c"i12@?0c4f8\00"
+// X32:   store i32 1073741824, i32* %block.tmp2
+
+// rdar://7635294
+
+
+int globalInt;
+void (^global)(void) = ^{ ++globalInt; };
+
+    
+void foo(int param) {
+   extern int rand(void);
+   extern void rand_r(int (^b)(char x, float y));   // name a function present at runtime
+   while (param--)
+      rand_r(^(char x, float y){ return x + (int)y + param + rand(); });  // generate a local block binding param
+}
+
+#if 0
+#include <stdio.h>
+enum {
+    BLOCK_HAS_COPY_DISPOSE =  (1 << 25),
+    BLOCK_HAS_CXX_OBJ =       (1 << 26),
+    BLOCK_IS_GLOBAL =         (1 << 28),
+    BLOCK_HAS_DESCRIPTOR =    (1 << 29),
+    BLOCK_HAS_OBJC_TYPE  =    (1 << 30)
+};
+
+struct block_descriptor_big {
+    unsigned long int reserved;
+    unsigned long int size;
+    void (*copy)(void *dst, void *src); // conditional on BLOCK_HAS_COPY_DISPOSE
+    void (*dispose)(void *);            // conditional on BLOCK_HAS_COPY_DISPOSE
+    const char *signature;                  // conditional on BLOCK_HAS_OBJC
+    const char *layout;                 // conditional on BLOCK_HAS_OBJC
+};
+struct block_descriptor_small {
+    unsigned long int reserved;
+    unsigned long int size;
+    const char *signature;              // conditional on BLOCK_HAS_OBJC
+    const char *layout;                 // conditional on BLOCK_HAS_OBJC
+};
+
+struct block_layout_abi { // can't change
+  void *isa;
+  int flags;
+  int reserved; 
+  void (*invoke)(void *, ...);
+  struct block_descriptor_big *descriptor;
+};
+
+const char *getBlockSignature(void *block) {
+   struct block_layout_abi *layout = (struct block_layout_abi *)block;
+   if ((layout->flags & BLOCK_HAS_OBJC_TYPE) != BLOCK_HAS_OBJC_TYPE) return NULL;
+   if (layout->flags & BLOCK_HAS_COPY_DISPOSE) 
+      return layout->descriptor->signature;
+   else
+      return ((struct block_descriptor_small *)layout->descriptor)->signature;
+}
+  
+    
+   
+int main(int argc, char *argv[]) {
+   printf("desired global flags: %d\n", BLOCK_IS_GLOBAL  | BLOCK_HAS_OBJC_TYPE);
+   printf("desired stack flags: %d\n",  BLOCK_HAS_OBJC_TYPE);
+   
+   printf("types for global: %s\n", getBlockSignature(global));
+   printf("types for local: %s\n", getBlockSignature(^int(char x, float y) { return (int)(y + x); }));
+   return 0;
+}
+
+/*
+x86_64
+desired global flags: 1342177280
+desired stack flags: 1073741824
+types for global: v8@?0
+types for local: i16@?0c8f12
+
+i386
+desired global flags: 1342177280
+desired stack flags: 1073741824
+types for global: v4@?0
+types for local: i12@?0c4f8
+*/
+#endif