r316689 - Simplify codegen and debug info generation for block context parameters.
Adrian Prantl via cfe-commits
cfe-commits at lists.llvm.org
Thu Oct 26 13:08:53 PDT 2017
Author: adrian
Date: Thu Oct 26 13:08:52 2017
New Revision: 316689
URL: http://llvm.org/viewvc/llvm-project?rev=316689&view=rev
Log:
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
Added:
cfe/trunk/test/CodeGen/debug-info-block-vars.c
Removed:
cfe/trunk/test/CodeGenObjC/debug-info-block-captured-self.m
Modified:
cfe/trunk/lib/CodeGen/CGBlocks.cpp
cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
cfe/trunk/lib/CodeGen/CGDebugInfo.h
Modified: cfe/trunk/lib/CodeGen/CGBlocks.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBlocks.cpp?rev=316689&r1=316688&r2=316689&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGBlocks.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGBlocks.cpp Thu Oct 26 13:08:52 2017
@@ -1293,20 +1293,17 @@ void CodeGenFunction::setBlockContextPar
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<llvm::AllocaInst>(alloc.getPointer()), Builder);
}
}
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=316689&r1=316688&r2=316689&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Thu Oct 26 13:08:52 2017
@@ -3694,9 +3694,9 @@ bool operator<(const BlockLayoutChunk &l
}
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::EmitDeclareOfBlockLite
// 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());
}
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.h?rev=316689&r1=316688&r2=316689&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.h (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.h Thu Oct 26 13:08:52 2017
@@ -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.
Added: cfe/trunk/test/CodeGen/debug-info-block-vars.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/debug-info-block-vars.c?rev=316689&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/debug-info-block-vars.c (added)
+++ cfe/trunk/test/CodeGen/debug-info-block-vars.c Thu Oct 26 13:08:52 2017
@@ -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();
+ });
+}
Removed: cfe/trunk/test/CodeGenObjC/debug-info-block-captured-self.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/debug-info-block-captured-self.m?rev=316688&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenObjC/debug-info-block-captured-self.m (original)
+++ cfe/trunk/test/CodeGenObjC/debug-info-block-captured-self.m (removed)
@@ -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.
- at class T;
- at interface S
- at end
- at interface Mode
--(int) count;
- at end
- at interface Context
- at end
- at interface ViewController
- at property (nonatomic, readwrite, strong) Context *context;
- at end
-typedef enum {
- Unknown = 0,
-} State;
- at interface Main : ViewController
-{
- T * t1;
- T * t2;
-}
- at property(readwrite, nonatomic) State state;
- at end
- at 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;
- }
- }];
- }];
-}
- at 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,
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