r215227 - DebugInfo: Blocks: Do not depend on LLVM argument numbering when choosing the debug info argument numbering.
David Blaikie
dblaikie at gmail.com
Fri Aug 8 10:10:14 PDT 2014
Author: dblaikie
Date: Fri Aug 8 12:10:14 2014
New Revision: 215227
URL: http://llvm.org/viewvc/llvm-project?rev=215227&view=rev
Log:
DebugInfo: Blocks: Do not depend on LLVM argument numbering when choosing the debug info argument numbering.
Due to the possible presence of return-by-out parameters, using the LLVM
argument number count when numbering debug info arguments can end up
off-by-one. This could produce two arguments with the same number, which
would in turn cause LLVM to emit only one of those arguments (whichever
it found last) or assert (r215157).
Added:
cfe/trunk/test/CodeGen/debug-info-block-out-return.c
Modified:
cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
cfe/trunk/lib/CodeGen/CGDebugInfo.h
cfe/trunk/lib/CodeGen/CGDecl.cpp
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=215227&r1=215226&r2=215227&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Fri Aug 8 12:10:14 2014
@@ -2947,6 +2947,7 @@ namespace {
void CGDebugInfo::EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
llvm::Value *Arg,
+ unsigned ArgNo,
llvm::Value *LocalAddr,
CGBuilderTy &Builder) {
assert(DebugKind >= CodeGenOptions::LimitedDebugInfo);
@@ -3078,7 +3079,7 @@ void CGDebugInfo::EmitDeclareOfBlockLite
llvm::DIDescriptor(scope),
Arg->getName(), tunit, line, type,
CGM.getLangOpts().Optimize, flags,
- cast<llvm::Argument>(Arg)->getArgNo() + 1);
+ ArgNo);
if (LocalAddr) {
// Insert an llvm.dbg.value into the current block.
Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.h?rev=215227&r1=215226&r2=215227&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.h (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.h Fri Aug 8 12:10:14 2014
@@ -266,7 +266,7 @@ public:
/// llvm.dbg.declare for the block-literal argument to a block
/// invocation function.
void EmitDeclareOfBlockLiteralArgVariable(const CGBlockInfo &block,
- llvm::Value *Arg,
+ llvm::Value *Arg, unsigned ArgNo,
llvm::Value *LocalAddr,
CGBuilderTy &Builder);
Modified: cfe/trunk/lib/CodeGen/CGDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDecl.cpp?rev=215227&r1=215226&r2=215227&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDecl.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDecl.cpp Fri Aug 8 12:10:14 2014
@@ -1634,7 +1634,8 @@ void CodeGenFunction::EmitParmDecl(const
if (CGM.getCodeGenOpts().getDebugInfo()
>= CodeGenOptions::LimitedDebugInfo) {
DI->setLocation(D.getLocation());
- DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, LocalAddr, Builder);
+ DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, ArgNo,
+ LocalAddr, Builder);
}
}
Added: cfe/trunk/test/CodeGen/debug-info-block-out-return.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/debug-info-block-out-return.c?rev=215227&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/debug-info-block-out-return.c (added)
+++ cfe/trunk/test/CodeGen/debug-info-block-out-return.c Fri Aug 8 12:10:14 2014
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -g -fblocks -emit-llvm -o - %s | FileCheck %s
+
+// Check that arg numbering is not affected by LLVM IR argument numbering -
+// since the latter is affected by return-by-out-parameter ABI requirements
+
+// 1 for the argument number (1 indexed), 2 for the line number
+// 16777218 == 1 << 24 | 2
+// 33554434 == 2 << 24 | 2
+// This explains the two magic numbers below, testing that these two arguments
+// are numbered correctly. If they are not numbered correctly they may appear
+// out of order or not at all (the latter would occur if they were both assigned
+// the same argument number by mistake).
+
+// CHECK: metadata !".block_descriptor", metadata !{{[0-9]*}}, i32 16777218, {{.*}} ; [ DW_TAG_arg_variable ] [.block_descriptor]
+// CHECK: metadata !"param", metadata !{{[0-9]*}}, i32 33554434, {{.*}} ; [ DW_TAG_arg_variable ] [param]
+
+// Line directive so we don't have to worry about how many lines preceed the
+// test code (as the line number is mangled in with the argument number as shown
+// above)
+#line 1
+typedef struct { int array[12]; } BigStruct_t;
+BigStruct_t (^a)() = ^(int param) {
+ BigStruct_t b;
+ return b;
+};
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