[llvm-objdump] Print source when subsequent lines in the translation unit come from the same line in two different headers.

[mmpozulp]

Summary

If you have these files

header1.h

int add1(int a) { return a + 1; }

header2.h

int return4() { return 4; }

test.c

#include "header1.h"
#include "header2.h"

and compile them with clang -g -c test.c -o test.o and run llvm-objdump --source test.o, the source from header2.h is missing

0000000000000000 add1:
; int add1(int a) { return a + 1; }
       0: 55                           	pushq	%rbp
       1: 48 89 e5                     	movq	%rsp, %rbp
       4: 89 7d fc                     	movl	%edi, -4(%rbp)
       7: 8b 45 fc                     	movl	-4(%rbp), %eax
       a: 83 c0 01                     	addl	$1, %eax
       d: 5d                           	popq	%rbp
       e: c3                           	retq
       f: 90                           	nop

0000000000000010 return4:
      10: 55                           	pushq	%rbp
      11: 48 89 e5                     	movq	%rsp, %rbp
      14: b8 04 00 00 00               	movl	$4, %eax
      19: 5d                           	popq	%rbp
      1a: c3                           	retq

This patch fixes this problem, interleaving the source from header2.h

0000000000000000 add1:
; int add1(int a) { return a + 1; }
       0: 55                           	pushq	%rbp
       1: 48 89 e5                     	movq	%rsp, %rbp
       4: 89 7d fc                     	movl	%edi, -4(%rbp)
       7: 8b 45 fc                     	movl	-4(%rbp), %eax
       a: 83 c0 01                     	addl	$1, %eax
       d: 5d                           	popq	%rbp
       e: c3                           	retq
       f: 90                           	nop

0000000000000010 return4:
; int return4() { return 4; }
      10: 55                           	pushq	%rbp
      11: 48 89 e5                     	movq	%rsp, %rbp
      14: b8 04 00 00 00               	movl	$4, %eax
      19: 5d                           	popq	%rbp
      1a: c3                           	retq

FYI I noticed this bug while working on a different patch requested by @jhenderson (https://bugs.llvm.org/show_bug.cgi?id=41905).

[grimar]

This LGTM. But please hold this on until anyone else take a look too.

[mmpozulp]

In D62461#1517931, @grimar wrote:

This LGTM. But please hold this on until anyone else take a look too.

Thanks, @grimar. Holding on...

[jhenderson]

LGTM, good catch! I think you can revise your summary to change headers to files, since it could happen in other cases too.

[mmpozulp]

Will do. Sorry for the delay, I'm fighting with svn. See my comment in https://reviews.llvm.org/D62369.

[mmpozulp]

Incorporate feedback from @jhenderson to change 'headers' to 'files' in test description.

[mmpozulp]

Committed as r362771.

llvm/test/tools/llvm-objdump/X86/Inputs/source-interleave-header1.h

+int add1(int a) { return a + 1; }

llvm/test/tools/llvm-objdump/X86/Inputs/source-interleave-header2.h

+int return4() { return 4; }

llvm/test/tools/llvm-objdump/X86/Inputs/source-interleave-same-line-different-file.c

+#include "source-interleave-header1.h"
+#include "source-interleave-header2.h"

llvm/test/tools/llvm-objdump/X86/Inputs/source-interleave-same-line-different-file.ll

+; NOTE: To be able to use this file as an input, the string SRC_COMPDIR needs
+;       replacing with a directory path by using sed or similar.
+
+; NOTE: This file was generated by running
+; clang -g -S -emit-llvm source-interleave-same-line-different-file.c -o \
+;   source-interleave-same-line-different-file.ll
+
+; ModuleID = 'source-interleave-same-line-different-file.c'
+source_filename = "source-interleave-same-line-different-file.c"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local i32 @add1(i32 %a) #0 !dbg !7 {
+entry:
+  %a.addr = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  call void @llvm.dbg.declare(metadata i32* %a.addr, metadata !12, metadata !DIExpression()), !dbg !13
+  %0 = load i32, i32* %a.addr, align 4, !dbg !14
+  %add = add nsw i32 %0, 1, !dbg !15
+  ret i32 %add, !dbg !16
+}
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local i32 @return4() #0 !dbg !17 {
+entry:
+  ret i32 4, !dbg !21
+}
+
+attributes #0 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (https://github.com/llvm/llvm-project.git af0add6c39f7fcc641a2ae38753a9bc4eae47b28)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "source-interleave-same-line-different-file.c", directory: "SRC_COMPDIR")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 9.0.0 (https://github.com/llvm/llvm-project.git af0add6c39f7fcc641a2ae38753a9bc4eae47b28)"}
+!7 = distinct !DISubprogram(name: "add1", scope: !8, file: !8, line: 1, type: !9, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!8 = !DIFile(filename: "./source-interleave-header1.h", directory: "SRC_COMPDIR")
+!9 = !DISubroutineType(types: !10)
+!10 = !{!11, !11}
+!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!12 = !DILocalVariable(name: "a", arg: 1, scope: !7, file: !8, line: 1, type: !11)
+!13 = !DILocation(line: 1, column: 14, scope: !7)
+!14 = !DILocation(line: 1, column: 26, scope: !7)
+!15 = !DILocation(line: 1, column: 28, scope: !7)
+!16 = !DILocation(line: 1, column: 19, scope: !7)
+!17 = distinct !DISubprogram(name: "return4", scope: !18, file: !18, line: 1, type: !19, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!18 = !DIFile(filename: "./source-interleave-header2.h", directory: "SRC_COMPDIR")
+!19 = !DISubroutineType(types: !20)
+!20 = !{!11}
+!21 = !DILocation(line: 1, column: 17, scope: !17)

llvm/test/tools/llvm-objdump/X86/Inputs/source-interleave.ll

-; NOTE: To be able to use this file as an input, the string SRC_CMPDIR needs
+; NOTE: To be able to use this file as an input, the string SRC_COMPDIR needs
 ;       replacing with a directory path by using sed or similar.
 
 ; ModuleID = 'source-interleave-x86_64.bc'
 source_filename = "source-interleave-x86_64.c"
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 @a = global i32 1, align 4, !dbg !4

llvm/test/tools/llvm-objdump/X86/source-interleave-same-line-different-file.test

+## Test that source is printed when subsequent lines in the translation unit
+## come from the same line in two different headers.
+
+# RUN: sed -e "s,SRC_COMPDIR,%/p/Inputs,g" %p/Inputs/source-interleave-same-line-different-file.ll > %t.ll
+# RUN: llc -o %t.o -filetype=obj -mtriple=x86_64-pc-linux %t.ll
+# RUN: llvm-objdump --source %t.o | FileCheck %s
+
+# CHECK:      0000000000000000 add1: 
+# CHECK-NEXT: ; int add1(int a) { return a + 1; }
+#
+# CHECK:      0000000000000010 return4:
+# CHECK-NEXT: ; int return4() { return 4; }

llvm/tools/llvm-objdump/llvm-objdump.cpp

void SourcePrinter::printSourceLine(raw_ostream &OS,
   DILineInfo LineInfo = DILineInfo();
   auto ExpectedLineInfo =
       Symbolizer->symbolizeCode(Obj->getFileName(), Address);
   if (!ExpectedLineInfo)
     consumeError(ExpectedLineInfo.takeError());
   else
     LineInfo = *ExpectedLineInfo;
 
-  if ((LineInfo.FileName == "<invalid>") || OldLineInfo.Line == LineInfo.Line ||
-      LineInfo.Line == 0)
+  if ((LineInfo.FileName == "<invalid>") || LineInfo.Line == 0 ||
+      ((OldLineInfo.Line == LineInfo.Line) &&
+       (OldLineInfo.FileName == LineInfo.FileName)))
     return;
 
   if (PrintLines)
     OS << Delimiter << LineInfo.FileName << ":" << LineInfo.Line << "\n";
   if (PrintSource) {
     if (SourceCache.find(LineInfo.FileName) == SourceCache.end())
       if (!cacheSource(LineInfo))
         return;