[llvm] r225011 - DebugInfo: Omit is_stmt from line table entries on the same line.
David Blaikie
dblaikie at gmail.com
Tue Dec 30 14:47:14 PST 2014
Author: dblaikie
Date: Tue Dec 30 16:47:13 2014
New Revision: 225011
URL: http://llvm.org/viewvc/llvm-project?rev=225011&view=rev
Log:
DebugInfo: Omit is_stmt from line table entries on the same line.
GCC does this for non-zero discriminators and since GCC doesn't produce
column info, that was the only place it comes up there. For LLVM, since
we can emit discriminators and/or column info, it makes more sense to
invert the condition and just test for changes in line number.
This should resolve at least some of the GDB 7.5 test suite failures
created by recent Clang changes that increase the location fidelity
(which, since Clang defaults to including column info on Linux by
default created a bunch of cases that confused GDB).
In theory we could do this better/differently by grouping actual source
statements together in a similar manner to the way lexical scopes are
handled but given that GDB isn't really in a position to consume that (&
users are probably somewhat used to different lines being different
'statements') this seems the safest and cheapest change. (I'm concerned
that doing this 'right' would bloat the debugloc data even further -
something Duncan's working hard to address)
Added:
llvm/trunk/test/DebugInfo/multiline.ll
Modified:
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
llvm/trunk/lib/MC/MCAsmStreamer.cpp
llvm/trunk/test/DebugInfo/X86/discriminator.ll
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=225011&r1=225010&r2=225011&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Tue Dec 30 16:47:13 2014
@@ -1026,8 +1026,10 @@ void DwarfDebug::beginInstruction(const
if (DL == PrologEndLoc) {
Flags |= DWARF2_FLAG_PROLOGUE_END;
PrologEndLoc = DebugLoc();
+ Flags |= DWARF2_FLAG_IS_STMT;
}
- if (PrologEndLoc.isUnknown())
+ if (DL.getLine() !=
+ Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
Flags |= DWARF2_FLAG_IS_STMT;
if (!DL.isUnknown()) {
Modified: llvm/trunk/lib/MC/MCAsmStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAsmStreamer.cpp?rev=225011&r1=225010&r2=225011&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAsmStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCAsmStreamer.cpp Tue Dec 30 16:47:13 2014
@@ -872,8 +872,6 @@ void MCAsmStreamer::EmitDwarfLocDirectiv
unsigned Isa,
unsigned Discriminator,
StringRef FileName) {
- this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
- Isa, Discriminator, FileName);
OS << "\t.loc\t" << FileNo << " " << Line << " " << Column;
if (Flags & DWARF2_FLAG_BASIC_BLOCK)
OS << " basic_block";
@@ -903,6 +901,8 @@ void MCAsmStreamer::EmitDwarfLocDirectiv
<< Line << ':' << Column;
}
EmitEOL();
+ this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
+ Isa, Discriminator, FileName);
}
MCSymbol *MCAsmStreamer::getDwarfLineTableSymbol(unsigned CUID) {
Modified: llvm/trunk/test/DebugInfo/X86/discriminator.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/discriminator.ll?rev=225011&r1=225010&r2=225011&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/discriminator.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/discriminator.ll Tue Dec 30 16:47:13 2014
@@ -60,4 +60,4 @@ attributes #0 = { nounwind uwtable "less
; CHECK: Address Line Column File ISA Discriminator Flags
; CHECK: ------------------ ------ ------ ------ --- ------------- -------------
-; CHECK: 0x0000000000000011 2 0 1 0 42 is_stmt
+; CHECK: 0x0000000000000011 2 0 1 0 42 {{$}}
Added: llvm/trunk/test/DebugInfo/multiline.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/multiline.ll?rev=225011&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/multiline.ll (added)
+++ llvm/trunk/test/DebugInfo/multiline.ll Tue Dec 30 16:47:13 2014
@@ -0,0 +1,81 @@
+; RUN: llc -filetype=asm -O0 < %s | FileCheck %s
+; RUN: llc -filetype=obj -O0 < %s | llvm-dwarfdump -debug-dump=line - | FileCheck %s --check-prefix=INT
+
+; Check that the assembly output properly handles is_stmt changes. And since
+; we're testing anyway, check the integrated assembler too.
+
+; Generated with clang from multiline.c:
+; void f1();
+; void f2() {
+; f1(); f1(); f1();
+; f1(); f1(); f1();
+; }
+
+
+; CHECK: .loc 1 2 0 #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 3 3 prologue_end #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 3 9 is_stmt 0 #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 3 15 #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 4 3 is_stmt 1 #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 4 9 is_stmt 0 #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 4 15 #
+; CHECK-NOT: .loc
+; CHECK: .loc 1 5 1 is_stmt 1 #
+
+; INT: {{^}}Address
+; INT: -----
+; INT-NEXT: 2 0 1 0 0 is_stmt{{$}}
+; INT-NEXT: 3 3 1 0 0 is_stmt prologue_end{{$}}
+; INT-NEXT: 3 9 1 0 0 {{$}}
+; INT-NEXT: 3 15 1 0 0 {{$}}
+; INT-NEXT: 4 3 1 0 0 is_stmt{{$}}
+; INT-NEXT: 4 9 1 0 0 {{$}}
+; INT-NEXT: 4 15 1 0 0 {{$}}
+; INT-NEXT: 5 1 1 0 0 is_stmt{{$}}
+
+
+; Function Attrs: nounwind uwtable
+define void @f2() #0 {
+entry:
+ call void (...)* @f1(), !dbg !11
+ call void (...)* @f1(), !dbg !12
+ call void (...)* @f1(), !dbg !13
+ call void (...)* @f1(), !dbg !14
+ call void (...)* @f1(), !dbg !15
+ call void (...)* @f1(), !dbg !16
+ ret void, !dbg !17
+}
+
+declare void @f1(...) #1
+
+attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!8, !9}
+!llvm.ident = !{!10}
+
+!0 = !{!"0x11\0012\00clang version 3.6.0 (trunk 225000) (llvm/trunk 224999)\000\00\000\00\001", !1, !2, !2, !3, !2, !2} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/multiline.c] [DW_LANG_C99]
+!1 = !{!"multiline.c", !"/tmp/dbginfo"}
+!2 = !{}
+!3 = !{!4}
+!4 = !{!"0x2e\00f2\00f2\00\002\000\001\000\000\000\000\002", !1, !5, !6, null, void ()* @f2, null, null, !2} ; [ DW_TAG_subprogram ] [line 2] [def] [f2]
+!5 = !{!"0x29", !1} ; [ DW_TAG_file_type ] [/tmp/dbginfo/multiline.c]
+!6 = !{!"0x15\00\000\000\000\000\000\000", null, null, null, !7, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = !{null}
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 2}
+!10 = !{!"clang version 3.6.0 (trunk 225000) (llvm/trunk 224999)"}
+!11 = !{i32 3, i32 3, !4, null}
+!12 = !{i32 3, i32 9, !4, null}
+!13 = !{i32 3, i32 15, !4, null}
+!14 = !{i32 4, i32 3, !4, null}
+!15 = !{i32 4, i32 9, !4, null}
+!16 = !{i32 4, i32 15, !4, null}
+!17 = !{i32 5, i32 1, !4, null}
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