From 356347b58d18b5b7984fbc5487532f49c7e98237 Mon Sep 17 00:00:00 2001 From: Adrian Prantl Date: Thu, 26 Oct 2017 20:08:52 +0000 Subject: [PATCH] Simplify codegen and debug info generation for block context parameters. The exisiting code goes out of its way to put block parameters into an alloca only at -O0, and then describes the funciton argument with a dbg.declare, which is undocumented in the LLVM-CFE contract and does not actually behave as intended after LLVM r642022. This patch just generates the alloca unconditionally, the mem2reg pass will eliminate it at -O1 and up anyway and points the dbg.declare to the alloca as intended (which mem2reg will then correctly rewrite into a dbg.value). This reapplies r316684 with some dead code removed. rdar://problem/35043980 Differential Revision: https://reviews.llvm.org/D39305 llvm-svn: 316689 --- clang/lib/CodeGen/CGBlocks.cpp | 17 ++--- clang/lib/CodeGen/CGDebugInfo.cpp | 16 ++--- clang/lib/CodeGen/CGDebugInfo.h | 4 +- clang/test/CodeGen/debug-info-block-vars.c | 20 ++++++ .../debug-info-block-captured-self.m | 72 ------------------- 5 files changed, 33 insertions(+), 96 deletions(-) create mode 100644 clang/test/CodeGen/debug-info-block-vars.c delete mode 100644 clang/test/CodeGenObjC/debug-info-block-captured-self.m diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp index 2915dabe5414..0bd9d7c506cf 100644 --- a/clang/lib/CodeGen/CGBlocks.cpp +++ b/clang/lib/CodeGen/CGBlocks.cpp @@ -1293,20 +1293,17 @@ void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D, llvm::Value *arg) { assert(BlockInfo && "not emitting prologue of block invocation function?!"); - llvm::Value *localAddr = nullptr; - if (CGM.getCodeGenOpts().OptimizationLevel == 0) { - // Allocate a stack slot to let the debug info survive the RA. - Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr"); - Builder.CreateStore(arg, alloc); - localAddr = Builder.CreateLoad(alloc); - } - + // Allocate a stack slot like for any local variable to guarantee optimal + // debug info at -O0. The mem2reg pass will eliminate it when optimizing. + Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr"); + Builder.CreateStore(arg, alloc); if (CGDebugInfo *DI = getDebugInfo()) { if (CGM.getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo) { DI->setLocation(D->getLocation()); - DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, arg, argNum, - localAddr, Builder); + DI->EmitDeclareOfBlockLiteralArgVariable( + *BlockInfo, D->getName(), argNum, + cast(alloc.getPointer()), Builder); } } diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index a73e4a98b3c3..3e4acd208f67 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -3694,9 +3694,9 @@ bool operator<(const BlockLayoutChunk &l, const BlockLayoutChunk &r) { } void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block, - llvm::Value *Arg, + StringRef Name, unsigned ArgNo, - llvm::Value *LocalAddr, + llvm::AllocaInst *Alloca, CGBuilderTy &Builder) { assert(DebugKind >= codegenoptions::LimitedDebugInfo); ASTContext &C = CGM.getContext(); @@ -3828,19 +3828,11 @@ void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block, // Create the descriptor for the parameter. auto *debugVar = DBuilder.createParameterVariable( - scope, Arg->getName(), ArgNo, tunit, line, type, + scope, Name, ArgNo, tunit, line, type, CGM.getLangOpts().Optimize, flags); - if (LocalAddr) { - // Insert an llvm.dbg.value into the current block. - DBuilder.insertDbgValueIntrinsic( - LocalAddr, debugVar, DBuilder.createExpression(), - llvm::DebugLoc::get(line, column, scope, CurInlinedAt), - Builder.GetInsertBlock()); - } - // Insert an llvm.dbg.declare into the current block. - DBuilder.insertDeclare(Arg, debugVar, DBuilder.createExpression(), + DBuilder.insertDeclare(Alloca, debugVar, DBuilder.createExpression(), llvm::DebugLoc::get(line, column, scope, CurInlinedAt), Builder.GetInsertBlock()); } diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h index 36de231f05fd..4f7b7f2a0d9c 100644 --- a/clang/lib/CodeGen/CGDebugInfo.h +++ b/clang/lib/CodeGen/CGDebugInfo.h @@ -398,8 +398,8 @@ public: /// Emit call to \c llvm.dbg.declare for the block-literal argument /// to a block invocation function. void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block, - llvm::Value *Arg, unsigned ArgNo, - llvm::Value *LocalAddr, + StringRef Name, unsigned ArgNo, + llvm::AllocaInst *LocalAddr, CGBuilderTy &Builder); /// Emit information about a global variable. diff --git a/clang/test/CodeGen/debug-info-block-vars.c b/clang/test/CodeGen/debug-info-block-vars.c new file mode 100644 index 000000000000..e0bb61e5e85f --- /dev/null +++ b/clang/test/CodeGen/debug-info-block-vars.c @@ -0,0 +1,20 @@ +// RUN: %clang_cc1 -x c -fblocks -debug-info-kind=standalone -emit-llvm -O0 \ +// RUN: -triple x86_64-apple-darwin -o - %s | FileCheck %s +// RUN: %clang_cc1 -x c -fblocks -debug-info-kind=standalone -emit-llvm -O1 \ +// RUN: -triple x86_64-apple-darwin -o - %s \ +// RUN: | FileCheck --check-prefix=CHECK-OPT %s + +// CHECK: define internal void @__f_block_invoke(i8* %.block_descriptor) +// CHECK: %.block_descriptor.addr = alloca i8*, align 8 +// CHECK: %block.addr = alloca <{ i8*, i32, i32, i8*, %struct.__block_descriptor* }>*, align 8 +// CHECK: store i8* %.block_descriptor, i8** %.block_descriptor.addr, align 8 +// CHECK: call void @llvm.dbg.declare(metadata i8** %.block_descriptor.addr, +// CHECK-SAME: metadata !DIExpression()) +// CHECK-OPT-NOT: alloca +// CHECK-OPT: call void @llvm.dbg.value(metadata i8* %.block_descriptor, +// CHECK-OPT-SAME: metadata !DIExpression()) +void f() { + a(^{ + b(); + }); +} diff --git a/clang/test/CodeGenObjC/debug-info-block-captured-self.m b/clang/test/CodeGenObjC/debug-info-block-captured-self.m deleted file mode 100644 index 302a01134252..000000000000 --- a/clang/test/CodeGenObjC/debug-info-block-captured-self.m +++ /dev/null @@ -1,72 +0,0 @@ -// RUN: %clang_cc1 -fblocks -debug-info-kind=limited -emit-llvm -triple x86_64-apple-darwin -o - %s | FileCheck %s -// -// Test that debug location is generated for a captured "self" inside -// a block. -// -// This test is split into two parts, this one for the frontend, and -// then llvm/test/DebugInfo/debug-info-block-captured-self.ll to -// ensure that DW_AT_location is generated for the captured self. -@class T; -@interface S -@end -@interface Mode --(int) count; -@end -@interface Context -@end -@interface ViewController -@property (nonatomic, readwrite, strong) Context *context; -@end -typedef enum { - Unknown = 0, -} State; -@interface Main : ViewController -{ - T * t1; - T * t2; -} -@property(readwrite, nonatomic) State state; -@end -@implementation Main -- (id) initWithContext:(Context *) context -{ - t1 = [self.context withBlock:^(id obj){ - id *mode1; - t2 = [mode1 withBlock:^(id object){ - Mode *mode2 = object; - if ([mode2 count] != 0) { - self.state = 0; - } - }]; - }]; -} -@end -// The important part of this test is that there is a dbg.value -// intrinsic associated with the implicit .block_descriptor argument -// of the block. We also test that this value gets alloca'd, so the -// register llocator won't accidentally kill it. - -// outer block: -// CHECK: define internal void {{.*}}_block_invoke{{.*}} - -// inner block: -// CHECK: define internal void {{.*}}_block_invoke{{.*}} -// CHECK: %[[MEM1:.*]] = alloca i8*, align 8 -// CHECK-NEXT: %[[MEM2:.*]] = alloca i8*, align 8 -// CHECK-NEXT: [[DBGADDR:%.*]] = alloca [[BLOCK_T:<{.*}>]]*, align 8 -// CHECK: store i8* [[BLOCK_DESC:%.*]], i8** %[[MEM1]], align 8 -// CHECK: %[[TMP0:.*]] = load i8*, i8** %[[MEM1]] -// CHECK: call void @llvm.dbg.value(metadata i8* %[[TMP0]], metadata ![[BDMD:[0-9]+]], metadata !{{.*}}) -// CHECK: call void @llvm.dbg.declare(metadata i8* [[BLOCK_DESC]], metadata ![[BDMD:[0-9]+]], metadata !{{.*}}) -// CHECK: store [[BLOCK_T]]* {{%.*}}, [[BLOCK_T]]** [[DBGADDR]], align 8 -// CHECK: call void @llvm.dbg.declare(metadata [[BLOCK_T]]** [[DBGADDR]], metadata ![[SELF:.*]], metadata !{{.*}}) -// make sure we are still in the same function -// CHECK: define {{.*}}__copy_helper_block_ -// Metadata -// CHECK: ![[MAIN:.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Main" -// CHECK-SAME: line: 23, -// CHECK: ![[PMAIN:.*]] = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: ![[MAIN]], -// CHECK: ![[BDMD]] = !DILocalVariable(name: ".block_descriptor", arg: -// CHECK: ![[SELF]] = !DILocalVariable(name: "self" -// CHECK-NOT: arg: -// CHECK-SAME: line: 40,