[lldb-dev] [llvm] r343874 - DwarfDebug: Pick next location in case of missing location at block begin

via lldb-dev lldb-dev at lists.llvm.org
Wed Oct 10 08:45:57 PDT 2018


Sorry for being late to the party, I have been away.

I am not persuaded that this patch is functionally correct.
It's lovely to reduce size, but not at the cost of telling
un-truths about source locations of instructions.  If the
instructions at the top of the block have no source location,
and you don't like using line 0, the correct path forward is to
understand why those instructions do not have a source location,
not to just pick one from a nearby instruction.

My choice would be to revert the LLVM patch rather than make
the LLDB test accommodate the un-truth.
--paulr

> -----Original Message-----
> From: lldb-dev [mailto:lldb-dev-bounces at lists.llvm.org] On Behalf Of Jim
> Ingham via lldb-dev
> Sent: Friday, October 05, 2018 9:30 PM
> To: Vedant Kumar
> Cc: Matthias Braun; Vedant Kumar via llvm-commits; LLDB
> Subject: Re: [lldb-dev] [llvm] r343874 - DwarfDebug: Pick next location in
> case of missing location at block begin
> 
> So in the test scenario, we have this code:
> 
>     printf("// Set second break point at this line.");
>     (text_list.push_back(std::string("!!!")));
> 
> and we have a breakpoint on the printf line.  We've just continued to hit
> the breakpoint at printf.  Then we do next twice.  That should certainly
> get us past the push_back.  If it does not that's either a bug in the line
> tables or in lldb's handling of them.  You would not expect to have to
> next three times to go from the start of the printf line to past the
> push_back of !!!.
> 
> Considered as a test about stepping, we should applaud the test for having
> caught a bug, and go figure out whether the line tables are bogus in this
> instance or just innovative and lldb will have to cope...
> 
> Considered as a test about data formatters, it is a little silly to try to
> drive it using next's since the push_backs are going to introduce a bunch
> of inlining and the debug information for inlining is often a bit wonky...
> 
> Best course is to use the breakpoints in this test to drive from point to
> point, and make a reduced stepping test case that just shows this bad
> stepping behavior.  Then we can fix the latter test failure either in
> clang or lldb as is appropriate.
> 
> Jim
> 
> 
> > On Oct 5, 2018, at 4:18 PM, Vedant Kumar via lldb-dev <lldb-
> dev at lists.llvm.org> wrote:
> >
> > No worries, I’ve relaxed the test for now in r343899 to get the bots
> going again. Essentially, the test will just step one more time to make
> sure the full effect of the push_back() is visible.
> >
> > If folks on lldb-dev (cc’d) have a better idea we can try it out.
> >
> > vedant
> >
> >> On Oct 5, 2018, at 4:15 PM, Matthias Braun <matze at braunis.de> wrote:
> >>
> >> So what should we do? Revert the llvm commit, fix the LLDB test, xfail
> on lldb? I'd be fine with any but don't want to learn how lldb tests work
> at this moment...
> >>
> >>> On Oct 5, 2018, at 4:11 PM, Vedant Kumar via llvm-commits <llvm-
> commits at lists.llvm.org> wrote:
> >>>
> >>> Sadly, after this commit TestDataFormatterLibcxxList.py started
> failing with:
> >>>
> >>> ```
> >>> output: Process 67333 stopped
> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = step over
> >>>     frame #0: 0x0000000100000eb0 a.out`main at main.cpp:33:16
> >>>    30  	    (text_list.push_back(std::string("smart")));
> >>>    31
> >>>    32  	    printf("// Set second break point at this line.");
> >>> -> 33  	    (text_list.push_back(std::string("!!!")));
> >>>     	               ^
> >>>    34
> >>>    35  	    std::list<int> countingList = {3141, 3142, 3142,3142,3142,
> 3142, 3142, 3141};
> >>>    36  	    countingList.sort();
> >>>
> >>>
> >>> runCmd: frame variable text_list[0]
> >>> output: (std::__1::basic_string<char, std::__1::char_traits<char>,
> std::__1::allocator<char> >) [0] = "goofy"
> >>>
> >>> Expecting sub string: goofy
> >>> Matched
> >>>
> >>> runCmd: frame variable text_list[3]
> >>> output: None
> >>>
> >>> Expecting sub string: !!!
> >>> ```
> >>>
> >>> URL: http://lab.llvm.org:8080/green/view/LLDB/job/lldb-cmake/10854
> >>>
> >>> I confirmed that reverting this fixes the issue.
> >>>
> >>> I think the problem is that we’re breaking on an instruction that
> looks like it’s on line 33, but it’s actually “before” the full effect of
> the push_back() is visible.
> >>>
> >>> In which case the test is wrong, because it’s setting the breakpoint
> too early…
> >>>
> >>> vedant
> >>>
> >>>> On Oct 5, 2018, at 11:29 AM, Matthias Braun via llvm-commits <llvm-
> commits at lists.llvm.org> wrote:
> >>>>
> >>>> Author: matze
> >>>> Date: Fri Oct  5 11:29:24 2018
> >>>> New Revision: 343874
> >>>>
> >>>> URL: http://llvm.org/viewvc/llvm-project?rev=343874&view=rev
> >>>> Log:
> >>>> DwarfDebug: Pick next location in case of missing location at block
> begin
> >>>>
> >>>> Context: Compiler generated instructions do not have a debug location
> >>>> assigned to them. However emitting 0-line records for all of them
> bloats
> >>>> the line tables for very little benefit so we usually avoid doing
> that.
> >>>>
> >>>> Not emitting anything will lead to the previous debug location
> getting
> >>>> applied to the locationless instructions. This is not desirable for
> >>>> block begin and after labels. Previously we would emit simply emit
> >>>> line-0 records in this case, this patch changes the behavior to do a
> >>>> forward search for a debug location in these cases before emitting a
> >>>> line-0 record to further reduce line table bloat.
> >>>>
> >>>> Inspired by the discussion in https://reviews.llvm.org/D52862
> >>>>
> >>>> Added:
> >>>>    llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.mir
> >>>> Modified:
> >>>>    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
> >>>>    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
> >>>>    llvm/trunk/test/DebugInfo/AArch64/line-header.ll
> >>>>    llvm/trunk/test/DebugInfo/ARM/single-constant-use-preserves-
> dbgloc.ll
> >>>>    llvm/trunk/test/DebugInfo/Mips/delay-slot.ll
> >>>>    llvm/trunk/test/DebugInfo/NVPTX/debug-info.ll
> >>>>    llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.ll
> >>>>
> >>>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=343874&r1=343
> 873&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
> >>>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Fri Oct  5
> 11:29:24 2018
> >>>> @@ -1313,6 +1313,49 @@ void DwarfDebug::collectEntityInfo(Dwarf
> >>>>   }
> >>>> }
> >>>>
> >>>> +static const DebugLoc &
> >>>> +findNextDebugLoc(MachineBasicBlock::const_iterator MBBI,
> >>>> +                 MachineBasicBlock::const_iterator MBBE) {
> >>>> +  static DebugLoc NoLocation;
> >>>> +  for ( ; MBBI != MBBE; ++MBBI) {
> >>>> +    if (MBBI->isDebugInstr())
> >>>> +      continue;
> >>>> +    const DebugLoc &DL = MBBI->getDebugLoc();
> >>>> +    if (DL)
> >>>> +      return DL;
> >>>> +  }
> >>>> +  return NoLocation;
> >>>> +}
> >>>> +
> >>>> +void DwarfDebug::emitDebugLoc(const DebugLoc &DL) {
> >>>> +  unsigned LastAsmLine =
> >>>> +      Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine();
> >>>> +
> >>>> +  // We have an explicit location, different from the previous
> location.
> >>>> +  // Don't repeat a line-0 record, but otherwise emit the new
> location.
> >>>> +  // (The new location might be an explicit line 0, which we do
> emit.)
> >>>> +  unsigned Line = DL.getLine();
> >>>> +  if (PrevInstLoc && Line == 0 && LastAsmLine == 0)
> >>>> +    return;
> >>>> +  unsigned Flags = 0;
> >>>> +  if (DL == PrologEndLoc) {
> >>>> +    Flags |= DWARF2_FLAG_PROLOGUE_END | DWARF2_FLAG_IS_STMT;
> >>>> +    PrologEndLoc = DebugLoc();
> >>>> +  }
> >>>> +  // If the line changed, we call that a new statement; unless we
> went to
> >>>> +  // line 0 and came back, in which case it is not a new statement.
> >>>> +  unsigned OldLine = PrevInstLoc ? PrevInstLoc.getLine() :
> LastAsmLine;
> >>>> +  if (Line && Line != OldLine)
> >>>> +    Flags |= DWARF2_FLAG_IS_STMT;
> >>>> +
> >>>> +  const MDNode *Scope = DL.getScope();
> >>>> +  recordSourceLine(Line, DL.getCol(), Scope, Flags);
> >>>> +
> >>>> +  // If we're not at line 0, remember this location.
> >>>> +  if (Line)
> >>>> +    PrevInstLoc = DL;
> >>>> +}
> >>>> +
> >>>> // Process beginning of an instruction.
> >>>> void DwarfDebug::beginInstruction(const MachineInstr *MI) {
> >>>>   DebugHandlerBase::beginInstruction(MI);
> >>>> @@ -1352,54 +1395,41 @@ void DwarfDebug::beginInstruction(const
> >>>>     // If we have already emitted a line-0 record, don't repeat it.
> >>>>     if (LastAsmLine == 0)
> >>>>       return;
> >>>> +    // By default we emit nothing to avoid line table bloat. However
> at the
> >>>> +    // beginning of a basic block or after a label it is undesirable
> to let
> >>>> +    // the previous location unchanged. In these cases do a forward
> search for
> >>>> +    // the next valid debug location.
> >>>> +    if (UnknownLocations == Default) {
> >>>> +      const MachineBasicBlock &MBB = *MI->getParent();
> >>>> +      if (!PrevLabel && PrevInstBB == &MBB)
> >>>> +        return;
> >>>> +
> >>>> +      const DebugLoc &NextDL = findNextDebugLoc(MI->getIterator(),
> MBB.end());
> >>>> +      if (NextDL) {
> >>>> +        emitDebugLoc(NextDL);
> >>>> +        return;
> >>>> +      }
> >>>> +    }
> >>>> +
> >>>> +    // We should emit a line-0 record.
> >>>>     // If user said Don't Do That, don't do that.
> >>>>     if (UnknownLocations == Disable)
> >>>>       return;
> >>>> -    // See if we have a reason to emit a line-0 record now.
> >>>> -    // Reasons to emit a line-0 record include:
> >>>> -    // - User asked for it (UnknownLocations).
> >>>> -    // - Instruction has a label, so it's referenced from somewhere
> else,
> >>>> -    //   possibly debug information; we want it to have a source
> location.
> >>>> -    // - Instruction is at the top of a block; we don't want to
> inherit the
> >>>> -    //   location from the physically previous (maybe unrelated)
> block.
> >>>> -    if (UnknownLocations == Enable || PrevLabel ||
> >>>> -        (PrevInstBB && PrevInstBB != MI->getParent())) {
> >>>> -      // Preserve the file and column numbers, if we can, to save
> space in
> >>>> -      // the encoded line table.
> >>>> -      // Do not update PrevInstLoc, it remembers the last non-0
> line.
> >>>> -      const MDNode *Scope = nullptr;
> >>>> -      unsigned Column = 0;
> >>>> -      if (PrevInstLoc) {
> >>>> -        Scope = PrevInstLoc.getScope();
> >>>> -        Column = PrevInstLoc.getCol();
> >>>> -      }
> >>>> -      recordSourceLine(/*Line=*/0, Column, Scope, /*Flags=*/0);
> >>>> +    // Emit a line-0 record now.
> >>>> +    // Preserve the file and column numbers, if we can, to save
> space in
> >>>> +    // the encoded line table.
> >>>> +    // Do not update PrevInstLoc, it remembers the last non-0 line.
> >>>> +    const MDNode *Scope = nullptr;
> >>>> +    unsigned Column = 0;
> >>>> +    if (PrevInstLoc) {
> >>>> +      Scope = PrevInstLoc.getScope();
> >>>> +      Column = PrevInstLoc.getCol();
> >>>>     }
> >>>> +    recordSourceLine(/*Line=*/0, Column, Scope, /*Flags=*/0);
> >>>>     return;
> >>>>   }
> >>>>
> >>>> -  // We have an explicit location, different from the previous
> location.
> >>>> -  // Don't repeat a line-0 record, but otherwise emit the new
> location.
> >>>> -  // (The new location might be an explicit line 0, which we do
> emit.)
> >>>> -  if (PrevInstLoc && DL.getLine() == 0 && LastAsmLine == 0)
> >>>> -    return;
> >>>> -  unsigned Flags = 0;
> >>>> -  if (DL == PrologEndLoc) {
> >>>> -    Flags |= DWARF2_FLAG_PROLOGUE_END | DWARF2_FLAG_IS_STMT;
> >>>> -    PrologEndLoc = DebugLoc();
> >>>> -  }
> >>>> -  // If the line changed, we call that a new statement; unless we
> went to
> >>>> -  // line 0 and came back, in which case it is not a new statement.
> >>>> -  unsigned OldLine = PrevInstLoc ? PrevInstLoc.getLine() :
> LastAsmLine;
> >>>> -  if (DL.getLine() && DL.getLine() != OldLine)
> >>>> -    Flags |= DWARF2_FLAG_IS_STMT;
> >>>> -
> >>>> -  const MDNode *Scope = DL.getScope();
> >>>> -  recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
> >>>> -
> >>>> -  // If we're not at line 0, remember this location.
> >>>> -  if (DL.getLine())
> >>>> -    PrevInstLoc = DL;
> >>>> +  emitDebugLoc(DL);
> >>>> }
> >>>>
> >>>> static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
> >>>>
> >>>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=343874&r1=34387
> 3&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
> >>>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Fri Oct  5
> 11:29:24 2018
> >>>> @@ -719,6 +719,9 @@ public:
> >>>>   bool tuneForLLDB() const { return DebuggerTuning ==
> DebuggerKind::LLDB; }
> >>>>   bool tuneForSCE() const { return DebuggerTuning ==
> DebuggerKind::SCE; }
> >>>>   /// @}
> >>>> +
> >>>> +private:
> >>>> +  void emitDebugLoc(const DebugLoc &DL);
> >>>> };
> >>>>
> >>>> } // end namespace llvm
> >>>>
> >>>> Modified: llvm/trunk/test/DebugInfo/AArch64/line-header.ll
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/AArch64/line-
> header.ll?rev=343874&r1=343873&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/test/DebugInfo/AArch64/line-header.ll (original)
> >>>> +++ llvm/trunk/test/DebugInfo/AArch64/line-header.ll Fri Oct  5
> 11:29:24 2018
> >>>> @@ -3,4 +3,4 @@
> >>>>
> >>>> ; check line table length is correctly calculated for both big and
> little endian
> >>>> CHECK-LABEL: .debug_line contents:
> >>>> -CHECK: total_length: 0x0000003f
> >>>> +CHECK: total_length: 0x0000003c
> >>>>
> >>>> Modified: llvm/trunk/test/DebugInfo/ARM/single-constant-use-
> preserves-dbgloc.ll
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/ARM/single-constant-use-preserves-
> dbgloc.ll?rev=343874&r1=343873&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/test/DebugInfo/ARM/single-constant-use-preserves-
> dbgloc.ll (original)
> >>>> +++ llvm/trunk/test/DebugInfo/ARM/single-constant-use-preserves-
> dbgloc.ll Fri Oct  5 11:29:24 2018
> >>>> @@ -31,11 +31,10 @@ if.then:
> >>>>
> >>>> if.end:                                           ; preds = %entry
> >>>> ; Materialize the constant.
> >>>> -; CHECK:      .loc    1 0
> >>>> +; CHECK:      .loc    1 7 5
> >>>> ; CHECK-NEXT: mvn     r0, #0
> >>>>
> >>>> ; The backend performs the store to %retval first, for some reason.
> >>>> -; CHECK-NEXT: .loc    1 7 5
> >>>> ; CHECK-NEXT: str     r0, [sp, #4]
> >>>>   store i32 -1, i32* %x, align 4, !dbg !19
> >>>>
> >>>>
> >>>> Modified: llvm/trunk/test/DebugInfo/Mips/delay-slot.ll
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/Mips/delay-
> slot.ll?rev=343874&r1=343873&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/test/DebugInfo/Mips/delay-slot.ll (original)
> >>>> +++ llvm/trunk/test/DebugInfo/Mips/delay-slot.ll Fri Oct  5 11:29:24
> 2018
> >>>> @@ -16,7 +16,7 @@
> >>>> ; CHECK: 0x0000000000000004      2      0      1   0             0
> is_stmt prologue_end
> >>>> ; CHECK: 0x0000000000000024      3      0      1   0             0
> is_stmt
> >>>> ; CHECK: 0x0000000000000034      4      0      1   0             0
> is_stmt
> >>>> -; CHECK: 0x0000000000000048      5      0      1   0             0
> is_stmt
> >>>> +; CHECK: 0x0000000000000044      5      0      1   0             0
> is_stmt
> >>>> ; CHECK: 0x0000000000000058      5      0      1   0             0
> is_stmt end_sequence
> >>>>
> >>>>
> >>>>
> >>>> Modified: llvm/trunk/test/DebugInfo/NVPTX/debug-info.ll
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/NVPTX/debug-
> info.ll?rev=343874&r1=343873&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/test/DebugInfo/NVPTX/debug-info.ll (original)
> >>>> +++ llvm/trunk/test/DebugInfo/NVPTX/debug-info.ll Fri Oct  5 11:29:24
> 2018
> >>>> @@ -36,6 +36,7 @@
> >>>> ; CHECK: setp.ge.s32     %p{{.+}}, %r{{.+}}, %r{{.+}};
> >>>> ; CHECK: .loc [[DEBUG_INFO_CU]] 7 7
> >>>> ; CHECK: @%p{{.+}} bra   [[BB:.+]];
> >>>> +; CHECK: .loc [[DEBUG_INFO_CU]] 8 13
> >>>> ; CHECK: ld.param.f32    %f{{.+}}, [{{.+}}];
> >>>> ; CHECK: ld.param.u64    %rd{{.+}}, [{{.+}}];
> >>>> ; CHECK: cvta.to.global.u64      %rd{{.+}}, %rd{{.+}};
> >>>> @@ -43,7 +44,6 @@
> >>>> ; CHECK: cvta.to.global.u64      %rd{{.+}}, %rd{{.+}};
> >>>> ; CHECK: mul.wide.u32    %rd{{.+}}, %r{{.+}}, 4;
> >>>> ; CHECK: add.s64         %rd{{.+}}, %rd{{.+}}, %rd{{.+}};
> >>>> -; CHECK: .loc [[DEBUG_INFO_CU]] 8 13
> >>>> ; CHECK: ld.global.f32   %f{{.+}}, [%rd{{.+}}];
> >>>> ; CHECK: add.s64         %rd{{.+}}, %rd{{.+}}, %rd{{.+}};
> >>>> ; CHECK: .loc [[DEBUG_INFO_CU]] 8 19
> >>>>
> >>>> Modified: llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.ll
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/X86/dwarf-no-source-
> loc.ll?rev=343874&r1=343873&r2=343874&view=diff
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.ll (original)
> >>>> +++ llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.ll Fri Oct  5
> 11:29:24 2018
> >>>> @@ -40,15 +40,14 @@ if.end:
> >>>>   ret void, !dbg !14
> >>>> }
> >>>>
> >>>> -; CHECK:      .loc 1 7 7
> >>>> +; CHECK:      .loc 1 7 7 prologue_end
> >>>> ; CHECK-NOT:  .loc
> >>>> -; CHECK:      .loc 1 0 7 is_stmt 0
> >>>> +; CHECK:      # %bb.1
> >>>> +; CHECK-NEXT: .file 2 "/tests/include.h"
> >>>> +; CHECK-NEXT: .loc 2 20 5
> >>>> ; CHECK-NOT:  .loc
> >>>> -; CHECK:      .loc 2 20 5 is_stmt 1
> >>>> ; CHECK:      .LBB0_2:
> >>>> -; CHECK-NEXT: .loc 2 0 5 is_stmt 0
> >>>> -; CHECK-NOT:  .loc
> >>>> -; CHECK:      .loc 1 10 3 is_stmt 1
> >>>> +; CHECK:      .loc 1 10 3
> >>>> ;
> >>>> ; DISABLE-NOT: .loc 1 0
> >>>>
> >>>>
> >>>> Added: llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.mir
> >>>> URL: http://llvm.org/viewvc/llvm-
> project/llvm/trunk/test/DebugInfo/X86/dwarf-no-source-
> loc.mir?rev=343874&view=auto
> >>>>
> ==========================================================================
> ====
> >>>> --- llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.mir (added)
> >>>> +++ llvm/trunk/test/DebugInfo/X86/dwarf-no-source-loc.mir Fri Oct  5
> 11:29:24 2018
> >>>> @@ -0,0 +1,74 @@
> >>>> +# RUN: llc -o - %s -start-before=patchable-function -use-unknown-
> locations=Default | FileCheck %s --check-prefixes=CHECK,DEFAULT
> >>>> +# RUN: llc -o - %s -start-before=patchable-function -use-unknown-
> locations=Enable | FileCheck %s --check-prefixes=CHECK,ENABLE
> >>>> +# RUN: llc -o - %s -start-before=patchable-function -use-unknown-
> locations=Disable | FileCheck %s --check-prefixes=CHECK,DISABLE
> >>>> +--- |
> >>>> +  target triple = "x86_64--"
> >>>> +
> >>>> +  !0 = !DIFile(filename: "dwarf-no-source-loc.mir", directory: "/")
> >>>> +  !1 = distinct !DICompileUnit(file: !0, language: DW_LANG_C,
> emissionKind: LineTablesOnly)
> >>>> +  !2 = distinct !DISubprogram(name: "func", unit: !1)
> >>>> +  !3 = !DILocation(line: 17, scope: !2)
> >>>> +  !4 = !DILocation(line: 42, scope: !2)
> >>>> +
> >>>> +  !llvm.dbg.cu = !{!1}
> >>>> +  !llvm.module.flags = !{!10, !11}
> >>>> +  !10 = !{i32 2, !"Dwarf Version", i32 4}
> >>>> +  !11 = !{i32 2, !"Debug Info Version", i32 3}
> >>>> +
> >>>> +  define void @func() !dbg !2 {
> >>>> +    unreachable
> >>>> +  }
> >>>> +...
> >>>> +---
> >>>> +name: func
> >>>> +body: |
> >>>> +  bb.0:
> >>>> +    NOOP
> >>>> +    NOOP
> >>>> +    $eax = MOV32ri 1, debug-location !3
> >>>> +    ; CHECK-LABEL: bb.0
> >>>> +    ; CHECK: nop
> >>>> +    ; CHECK: nop
> >>>> +    ; CHECK: .loc 1 17 0 prologue_end
> >>>> +    ; CHECK: movl $1, %eax
> >>>> +
> >>>> +  bb.1:
> >>>> +    NOOP
> >>>> +    $ebx = MOV32ri 2, debug-location !4
> >>>> +    ; CHECK-LABEL: bb.1
> >>>> +    ; DEFAULT: .loc 1 42 0
> >>>> +    ; ENABLE: .loc 1 0
> >>>> +    ; DISABLE-NOT: .loc 1 0
> >>>> +    ; CHECK: nop
> >>>> +    ; ENABLE: .loc 1 42 0
> >>>> +    ; CHECK: movl $2, %ebx
> >>>> +
> >>>> +  bb.2:
> >>>> +    NOOP
> >>>> +    ; CHECK-LABEL: bb.2
> >>>> +    ; DEFAULT: .loc 1 0 0 is_stmt 0
> >>>> +    ; ENABLE: .loc 1 0 0 is_stmt 0
> >>>> +    ; DISABLE-NOT: .loc 1 0
> >>>> +    ; CHECK: nop
> >>>> +
> >>>> +  bb.3:
> >>>> +    NOOP
> >>>> +    $ecx = MOV32ri 3, debug-location !3
> >>>> +    ; CHECK-LABEL: bb.3
> >>>> +    ; CHECK: nop
> >>>> +    ; DEFAULT: .loc 1 17 0 is_stmt 1
> >>>> +    ; ENABLE: .loc 1 17 0 is_stmt 1
> >>>> +    ; DISABLE-NOT: .loc 1 0
> >>>> +    ; CHECK: movl $3, %ecx
> >>>> +
> >>>> +  bb.4:
> >>>> +    NOOP
> >>>> +    $edx = MOV32ri 4, debug-location !4
> >>>> +    ; CHECK: bb.4
> >>>> +    ; DEFAULT: .loc 1 42 0
> >>>> +    ; ENABLE: .loc 1 0 0 is_stmt 0
> >>>> +    ; DISABLE-NOT: .loc 1 0
> >>>> +    ; CHECK: nop
> >>>> +    ; ENABLE: .loc 1 42 0 is_stmt 1
> >>>> +    ; CHECK: movl $4, %edx
> >>>> +...
> >>>>
> >>>>
> >>>> _______________________________________________
> >>>> llvm-commits mailing list
> >>>> llvm-commits at lists.llvm.org
> >>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
> >>>
> >>> _______________________________________________
> >>> llvm-commits mailing list
> >>> llvm-commits at lists.llvm.org
> >>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
> >>
> >
> > _______________________________________________
> > lldb-dev mailing list
> > lldb-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> 
> _______________________________________________
> lldb-dev mailing list
> lldb-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev


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