[LLVMdev] DW_AT_location not getting generated for local variables

[Joe Groff]

I figured out my previous problem with DIBuilder. However, now I can't seem
to get the compiler to emit location information for local variables.
Here's how my IR looks:

---
define i32 @"\01_main"() {
init:
  %exception1 = alloca i8*
  %0 = alloca i32
  %"bar:Int32" = alloca i32
  %1 = alloca i32
  %2 = alloca i32*
  br label %code

code:                                             ; preds = %init
  call void @llvm.dbg.declare(metadata !{i32* %"bar:Int32"}, metadata !13)
  store i32 1, i32* %"bar:Int32", !dbg !16
  store i32 1, i32* %1, !dbg !17
  %3 = load i32* %"bar:Int32", !dbg !17
  %4 = load i32* %1, !dbg !17
  %5 = add i32 %3, %4, !dbg !17
  store i32 %5, i32* %"bar:Int32", !dbg !17
  store i32* %"bar:Int32", i32** %2, !dbg !18
  %6 = load i32** %2, !dbg !18
  %7 = load i32* %6, !dbg !18
  store i32 %7, i32* %0, !dbg !18
  br label %return, !dbg !18

return:                                           ; preds = %code
  %8 = load i32* %0
  ret i32 %8

exception:                                        ; No predecessors!
  unreachable
}

declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone

!llvm.dbg.cu = !{!0}

!0 = metadata !{i32 720913, i32 0, i32 49572, metadata !"foo.clay",
metadata !"", metadata !"clay compiler 0.1git", i1 true, i1 false, metadata
!"", i32 0, 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 720942, i32 0, metadata !6, metadata !"foo", metadata
!"foo", metadata !"\01_main", metadata !7, i32 1, metadata !8, i1 false, i1
true, i32 0, i32 0, i32 0, i32 0, i1 false, i32 ()* @"\01_main", null,
null, metadata !11} ; [ DW_TAG_subprogram ]
!6 = metadata !{i32 720953, null, metadata !"__main__", metadata !7, i32 1}
; [ DW_TAG_namespace ]
!7 = metadata !{i32 720937, metadata !"foo.clay", metadata !"", null} ; [
DW_TAG_file_type ]
!8 = metadata !{i32 720917, i32 0, metadata !"", i32 0, i32 0, i64 0, i64
0, i32 0, i32 0, i32 0, metadata !9, i32 0, i32 0} ; [
DW_TAG_subroutine_type ]
!9 = metadata !{metadata !10}
!10 = metadata !{i32 720932, null, metadata !"Int32", null, i32 0, i64 32,
i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
!11 = metadata !{metadata !12}
!12 = metadata !{metadata !13}
!13 = metadata !{i32 721152, metadata !14, metadata !"bar", metadata !7,
i32 2, metadata !10, i32 0, i32 0} ; [ DW_TAG_auto_variable ]
!14 = metadata !{i32 720907, metadata !15, i32 1, i32 1, metadata !7, i32
1} ; [ DW_TAG_lexical_block ]
!15 = metadata !{i32 720907, metadata !5, i32 1, i32 1, metadata !7, i32 0}
; [ DW_TAG_lexical_block ]
!16 = metadata !{i32 2, i32 2, metadata !14, null}
!17 = metadata !{i32 3, i32 3, metadata !14, null}
!18 = metadata !{i32 4, i32 4, metadata !14, null}
---

And this is what dwarfdump on the compiled object file shows. The
TAG_variable entry for 'bar' is missing its AT_location.

---
----------------------------------------------------------------------
 File: foo.o (x86_64)
----------------------------------------------------------------------
.debug_info contents:

0x00000000: Compile Unit: length = 0x000000a9  version = 0x0002
 abbr_offset = 0x00000000  addr_size = 0x08  (next CU at 0x000000ad)

0x0000000b: TAG_compile_unit [1] *
             AT_producer( "clay compiler 0.1git" )
             AT_language( Unknown DW_LANG constant: 0xc1a4 )
             AT_name( "foo.clay" )
             AT_entry_pc( 0x0000000000000000 )
             AT_stmt_list( 0x00000000 )

0x00000038:     TAG_namespace [2] *
                 AT_sibling( {0x0000005c} )
                 AT_name( "__main__" )
                 AT_decl_file(
"/Users/joe/Documents/Code/others/clay/foo.clay" )
                 AT_decl_line( 1 )

0x00000048:         TAG_subprogram [3]
                     AT_MIPS_linkage_name( "_main" )
                     AT_name( "foo" )
                     AT_decl_file(
"/Users/joe/Documents/Code/others/clay/foo.clay" )
                     AT_decl_line( 1 )
                     AT_type( {0x0000005c} ( Int32 ) )
                     AT_external( 0x01 )
                     AT_declaration( 0x01 )

0x0000005b:         NULL

0x0000005c:     TAG_base_type [4]
                 AT_name( "Int32" )
                 AT_encoding( DW_ATE_signed )
                 AT_byte_size( 0x04 )

0x00000065:     TAG_subprogram [5] *
                 AT_specification( {0x00000048} ( "_main" ) )
                 AT_low_pc( 0x0000000000000020 )
                 AT_high_pc( 0x0000000000000051 )
                 AT_frame_base( rbp )

0x0000007c:         TAG_lexical_block [6] *
                     AT_low_pc( 0x0000000000000028 )
                     AT_high_pc( 0x000000000000004c )

0x0000008d:             TAG_lexical_block [6] *
                         AT_low_pc( 0x0000000000000028 )
                         AT_high_pc( 0x000000000000004c )

0x0000009e:                 TAG_variable [7]
                             AT_name( "bar" )
                             AT_decl_file(
"/Users/joe/Documents/Code/others/clay/foo.clay" )
                             AT_decl_line( 2 )
                             AT_type( {0x0000005c} ( Int32 ) )

0x000000a9:                 NULL

0x000000aa:             NULL

0x000000ab:         NULL

0x000000ac:     NULL
---

Am I using llvm.dbg.declare correctly? Is there something missing in my
metadata?

-Joe
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