Carlo Kok
2012-Jul-27 09:35 UTC
[LLVMdev] llvm dwarf debug info for locals with llvm.dbg.define
Hi, I had a problem with LLVM not emitting local variable info, even though I had calls to llvm.dbg.define. After some tracking I found that the llvm.dbg.declare (and probably value too) have to have a !dbg !nr after them to get emitted at all. maybe someone can adjust http://llvm.org/docs/SourceLevelDebugging.html#format_common_declare that the two llvm.dbg. functions need a !dbg line info associated with them? Code i used that does not work (but does if !dbg !14 is added): ; ModuleID = 'meh' @.str0 = linker_private constant [7 x i8] c"heh %b\00", align 1 @"\01L_OBJC_IMAGE_INFO" = internal constant [2 x i32] [i32 0, i32 16], section "__DATA, __objc_imageinfo, regular, no_dead_strip" @llvm.used = appending global [1 x i8*] [i8* bitcast ([2 x i32]* @"\01L_OBJC_IMAGE_INFO" to i8*)], section "llvm.metadata" define i32 @main() uwtable { %b = alloca i32 %Result = alloca i32 call void @llvm.dbg.declare(metadata !{i32* %b}, metadata !10) call void @llvm.dbg.declare(metadata !{i32* %Result}, metadata !13) store i32 15, i32* %b, !dbg !14 %1 = load i32* %b, !dbg !15 %2 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([7 x i8]* @.str0, i32 0, i32 0), i32 %1), !dbg !15 %3 = load i32* %Result, !dbg !16 ret i32 %3, !dbg !16 ; No predecessors! unreachable, !dbg !16 } declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone declare i32 @printf(i8*, ...) !llvm.dbg.cu = !{!0} !0 = metadata !{i32 786449, i32 0, i32 16, metadata !"meh.c", metadata !"/path/", metadata !"5.0.0.142", i1 true, i1 false, metadata !"", i32 2, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ] !1 = metadata !{metadata !2} !2 = metadata !{i32 0} !3 = metadata !{metadata !4} !4 = metadata !{metadata !5} !5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"Main", metadata !"Main", metadata !"", metadata !6, i32 10, metadata !7, i1 true, i1 true, i32 0, i32 0, null, i32 0, i1 false, i32 ()* @main, null, null, metadata !1, i32 10} ; [ DW_TAG_subprogram ] !6 = metadata !{i32 786473, metadata !"meh.c", metadata !"/path/", null} ; [ DW_TAG_file_type ] !7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] !8 = metadata !{metadata !9} !9 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] !10 = metadata !{i32 786688, metadata !11, metadata !"b", metadata !6, i32 10, metadata !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] !11 = metadata !{i32 786443, metadata !12, i32 10, i32 1, metadata !6, i32 1} ; [ DW_TAG_lexical_block ] !12 = metadata !{i32 786443, metadata !5, i32 10, i32 1, metadata !6, i32 0} ; [ DW_TAG_lexical_block ] !13 = metadata !{i32 786688, metadata !11, metadata !"Result", metadata !6, i32 10, metadata !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] !14 = metadata !{i32 11, i32 7, metadata !11, null} !15 = metadata !{i32 12, i32 3, metadata !11, null} !16 = metadata !{i32 13, i32 1, metadata !11, null} -- Carlo Kok
Eric Christopher
2012-Jul-27 18:22 UTC
[LLVMdev] llvm dwarf debug info for locals with llvm.dbg.define
On Jul 27, 2012, at 2:35 AM, Carlo Kok <ck at remobjects.com> wrote:> Hi, > > I had a problem with LLVM not emitting local variable info, even though > I had calls to llvm.dbg.define. After some tracking I found that the > llvm.dbg.declare (and probably value too) have to have a !dbg !nr after > them to get emitted at all. maybe someone can adjust > http://llvm.org/docs/SourceLevelDebugging.html#format_common_declare > that the two llvm.dbg. functions need a !dbg line info associated with them?I suppose, but a declare isn't too useful unless you know where it was declared. How were you constructing these declares such that they didn't have line information? -eric
Carlo Kok
2012-Jul-28 11:42 UTC
[LLVMdev] llvm dwarf debug info for locals with llvm.dbg.define
Op 27-7-2012 20:22, Eric Christopher schreef:> > On Jul 27, 2012, at 2:35 AM, Carlo Kok <ck at remobjects.com> wrote: > >> Hi, >> >> I had a problem with LLVM not emitting local variable info, even though >> I had calls to llvm.dbg.define. After some tracking I found that the >> llvm.dbg.declare (and probably value too) have to have a !dbg !nr after >> them to get emitted at all. maybe someone can adjust >> http://llvm.org/docs/SourceLevelDebugging.html#format_common_declare >> that the two llvm.dbg. functions need a !dbg line info associated with them? > > I suppose, but a declare isn't too useful unless you know where it was declared. > How were you constructing these declares such that they didn't > have line information?I used the DIBuilder class to do this. The auto_var struct already has a line nr& file field in it to define where it really is defined.
Maybe Matching Threads
- [LLVMdev] llvm dwarf debug info for locals with llvm.dbg.define
- [LLVMdev] Does llvm-gcc emit column # info?
- [LLVMdev] DWARF not being generated for local variable, though MD looks right(?)
- [LLVMdev] DWARF not being generated for local variable, though MD looks right(?)
- [LLVMdev] Trying to access the user defined variable name