[clang] 5b9a072 - Revert a5c8ec4 "[CGDebugInfo] Emit subprograms for decls when AT_tail_call is understood"
Hans Wennborg via cfe-commits
cfe-commits at lists.llvm.org
Thu Nov 7 01:31:14 PST 2019
Author: Hans Wennborg
Date: 2019-11-07T10:30:07+01:00
New Revision: 5b9a072c39c0c34a290abd19e4aca8208a9afae6
URL: https://github.com/llvm/llvm-project/commit/5b9a072c39c0c34a290abd19e4aca8208a9afae6
DIFF: https://github.com/llvm/llvm-project/commit/5b9a072c39c0c34a290abd19e4aca8208a9afae6.diff
LOG: Revert a5c8ec4 "[CGDebugInfo] Emit subprograms for decls when AT_tail_call is understood"
This caused Chromium builds to fail with "inlinable function call in a function
with debug info must have a !dbg location" errors. See
https://bugs.chromium.org/p/chromium/issues/detail?id=1022296#c1 for a
reproducer.
> Currently, clang emits subprograms for declared functions when the
> target debugger or DWARF standard is known to support entry values
> (DW_OP_entry_value & the GNU equivalent).
>
> Treat DW_AT_tail_call the same way to allow debuggers to follow cross-TU
> tail calls.
>
> Pre-patch debug session with a cross-TU tail call:
>
> ```
> * frame #0: 0x0000000100000fa4 main`target at b.c:4:3 [opt]
> frame #1: 0x0000000100000f99 main`main at a.c:8:10 [opt]
> ```
>
> Post-patch (note that the tail-calling frame, "helper", is visible):
>
> ```
> * frame #0: 0x0000000100000fa4 main`target at b.c:4:3 [opt]
> frame #1: 0x0000000100000f80 main`helper [opt] [artificial]
> frame #2: 0x0000000100000f99 main`main at a.c:8:10 [opt]
> ```
>
> rdar://46577651
>
> Differential Revision: https://reviews.llvm.org/D69743
Added:
Modified:
clang/lib/CodeGen/CGDebugInfo.cpp
clang/test/CodeGen/debug-info-extern-call.c
clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp
llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index c0c8fd3c8f16..e0bb3fda7acf 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3748,7 +3748,9 @@ void CGDebugInfo::EmitFunctionDecl(GlobalDecl GD, SourceLocation Loc,
void CGDebugInfo::EmitFuncDeclForCallSite(llvm::CallBase *CallOrInvoke,
QualType CalleeType,
const FunctionDecl *CalleeDecl) {
- if (!CallOrInvoke || getCallSiteRelatedAttrs() == llvm::DINode::FlagZero)
+ auto &CGOpts = CGM.getCodeGenOpts();
+ if (!CGOpts.EnableDebugEntryValues || !CGM.getLangOpts().Optimize ||
+ !CallOrInvoke)
return;
auto *Func = CallOrInvoke->getCalledFunction();
@@ -4822,10 +4824,10 @@ llvm::DINode::DIFlags CGDebugInfo::getCallSiteRelatedAttrs() const {
bool SupportsDWARFv4Ext =
CGM.getCodeGenOpts().DwarfVersion == 4 &&
(CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB ||
- CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::GDB);
+ (CGM.getCodeGenOpts().EnableDebugEntryValues &&
+ CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::GDB));
- if (!SupportsDWARFv4Ext && CGM.getCodeGenOpts().DwarfVersion < 5 &&
- !CGM.getCodeGenOpts().EnableDebugEntryValues)
+ if (!SupportsDWARFv4Ext && CGM.getCodeGenOpts().DwarfVersion < 5)
return llvm::DINode::FlagZero;
return llvm::DINode::FlagAllCallsDescribed;
diff --git a/clang/test/CodeGen/debug-info-extern-call.c b/clang/test/CodeGen/debug-info-extern-call.c
index 7f58fe59a635..e35669b78f93 100644
--- a/clang/test/CodeGen/debug-info-extern-call.c
+++ b/clang/test/CodeGen/debug-info-extern-call.c
@@ -1,21 +1,8 @@
-// When entry values are emitted, expect a subprogram for extern decls so that
-// the dwarf generator can describe call site parameters at extern call sites.
-//
-// RUN: %clang -Xclang -femit-debug-entry-values -g -O2 -target x86_64-none-linux-gnu -S -emit-llvm %s -o - | FileCheck %s -check-prefix=ENTRY-VAL
-// ENTRY-VAL: !DISubprogram(name: "fn1"
+// RUN: %clang -Xclang -femit-debug-entry-values -g -O2 -target x86_64-none-linux-gnu -S -emit-llvm %s -o - | FileCheck %s -check-prefix=CHECK-EXT
+// CHECK-EXT: !DISubprogram(name: "fn1"
-// Similarly, when the debugger tuning is gdb, expect a subprogram for extern
-// decls so that the dwarf generator can describe information needed for tail
-// call frame reconstrution.
-//
-// RUN: %clang -g -O2 -target x86_64-none-linux-gnu -ggdb -S -emit-llvm %s -o - | FileCheck %s -check-prefix=GDB
-// GDB: !DISubprogram(name: "fn1"
-//
-// Do not emit a subprogram for extern decls when entry values are disabled and
-// the tuning is not set to gdb.
-//
-// RUN: %clang -g -O2 -target x86_64-none-linux-gnu -gsce -S -emit-llvm %s -o - | FileCheck %s -check-prefix=SCE
-// SCE-NOT: !DISubprogram(name: "fn1"
+// RUN: %clang -g -O2 -target x86_64-none-linux-gnu -S -emit-llvm %s -o - | FileCheck %s
+// CHECK-NOT: !DISubprogram(name: "fn1"
extern int fn1(int a, int b);
diff --git a/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp b/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp
index 667c2469b55e..1cb2b6c609f3 100644
--- a/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp
+++ b/clang/test/CodeGenCXX/dbg-info-all-calls-described.cpp
@@ -56,7 +56,6 @@
// NO-ATTR-NOT: FlagAllCallsDescribed
-// HAS-ATTR-DAG: DISubprogram(name: "declaration1", {{.*}}, flags: DIFlagPrototyped
// HAS-ATTR-DAG: DISubprogram(name: "declaration2", {{.*}}, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition
// HAS-ATTR-DAG: DISubprogram(name: "struct1", {{.*}}, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
// HAS-ATTR-DAG: DISubprogram(name: "struct1", {{.*}}, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition
diff --git a/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll b/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll
index 33e06faba57b..c37ce1eb7fbe 100644
--- a/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll
+++ b/llvm/test/DebugInfo/X86/dwarf-callsite-related-attrs.ll
@@ -25,14 +25,6 @@
@sink = global i32 0, align 4, !dbg !0
-define void @__has_no_subprogram() {
-entry:
- %0 = load volatile i32, i32* @sink, align 4
- %inc = add nsw i32 %0, 1
- store volatile i32 %inc, i32* @sink, align 4
- ret void
-}
-
; ASM: DW_TAG_subprogram
; ASM: DW_AT_call_all_calls
; OBJ: [[bat_sp:.*]]: DW_TAG_subprogram
@@ -78,7 +70,6 @@ entry:
; OBJ: DW_AT_call_tail_call
define void @_Z3foov() !dbg !25 {
entry:
- tail call void @__has_no_subprogram()
tail call void @_Z3barv(), !dbg !26
tail call void @_Z3batv(), !dbg !27
tail call void @_Z3barv(), !dbg !26
More information about the cfe-commits
mailing list