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[lld-macho] Support creating N_SO stab for DWARF5 compile units

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In DWARF5, the `DW_AT_name` and `DW_AT_comp_dir` attributes are encoded
using the `strx*` forms, which specify an index into `__debug_str_offs`.
This commit adds that section to DwarfObject, so the debug info parser
can resolve these references.

The test case was manually adapted from stabs-icf.s.

Fixes #51668

Differential Revision: https://reviews.llvm.org/D130559
This commit is contained in:
Daniel Bertalan 2022-07-26 12:06:39 +02:00
parent 7fac9c9141
commit f2c7f75f61
4 changed files with 79 additions and 0 deletions
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1
lld/MachO/Dwarf.cpp
View File

@ -30,6 +30,7 @@ std::unique_ptr<DwarfObject> DwarfObject::create(ObjFile *obj) {
StringSwitch<StringRef *>(isec->getName())
.Case(section_names::debugInfo, &dObj->infoSection.Data)
.Case(section_names::debugLine, &dObj->lineSection.Data)
.Case(section_names::debugStrOffs, &dObj->strOffsSection.Data)
.Case(section_names::debugAbbrev, &dObj->abbrevSection)
.Case(section_names::debugStr, &dObj->strSection)
.Default(nullptr)) {

5
lld/MachO/Dwarf.h
View File

@ -41,6 +41,10 @@ public:
return lineSection;
}
llvm::DWARFSection const &getStrOffsetsSection() const override {
return strOffsSection;
}
// Returns an instance of DwarfObject if the given object file has the
// relevant DWARF debug sections.
static std::unique_ptr<DwarfObject> create(ObjFile *);
@ -48,6 +52,7 @@ public:
private:
llvm::DWARFSection infoSection;
llvm::DWARFSection lineSection;
llvm::DWARFSection strOffsSection;
llvm::StringRef abbrevSection;
llvm::StringRef strSection;
};

1
lld/MachO/InputSection.h
View File

@ -302,6 +302,7 @@ constexpr const char debugAbbrev[] = "__debug_abbrev";
constexpr const char debugInfo[] = "__debug_info";
constexpr const char debugLine[] = "__debug_line";
constexpr const char debugStr[] = "__debug_str";
constexpr const char debugStrOffs[] = "__debug_str_offs";
constexpr const char ehFrame[] = "__eh_frame";
constexpr const char gccExceptTab[] = "__gcc_except_tab";
constexpr const char export_[] = "__export";

72
lld/test/MachO/stabs-dwarf5.s Normal file
View File

@ -0,0 +1,72 @@
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin -dwarf-version=5 %s -o %t.o
# RUN: %lld -lSystem %t.o -o %t
# RUN: dsymutil -s %t | FileCheck %s -DDIR=%t -DSRC_PATH=%t.o
# CHECK: (N_SO ) 00 0000 0000000000000000 '/tmp{{[/\\]}}test.cpp'
# CHECK-NEXT: (N_OSO ) 03 0001 {{.*}} '[[SRC_PATH]]'
# CHECK-NEXT: (N_FUN ) 01 0000 [[#%.16x,MAIN:]] '_main'
# CHECK-NEXT: (N_FUN ) 00 0000 0000000000000001{{$}}
# CHECK-DAG: ( SECT EXT) 01 0000 [[#MAIN]] '_main'
# CHECK-DAG: ( {{.*}}) {{[0-9]+}} 0010 {{[0-9a-f]+}} '__mh_execute_header'
# CHECK-DAG: ( {{.*}}) {{[0-9]+}} 0100 0000000000000000 'dyld_stub_binder'
# CHECK-EMPTY:
.text
.globl _main
.subsections_via_symbols
_main:
Lfunc_begin0:
retq
Lfunc_end0:
.section __DWARF,__debug_str_offs,regular,debug
Lsection_str_off:
.long 12 ## Length of String Offsets Set
.short 5
.short 0
Lstr_offsets_base0:
.section __DWARF,__debug_str,regular,debug
.asciz "test.cpp" ## string offset=0
.asciz "/tmp" ## string offset=9
.section __DWARF,__debug_str_offs,regular,debug
.long 0
.long 9
.section __DWARF,__debug_abbrev,regular,debug
Lsection_abbrev:
.byte 1 ## Abbreviation Code
.byte 17 ## DW_TAG_compile_unit
.byte 1 ## DW_CHILDREN_yes
.byte 17 ## DW_AT_low_pc
.byte 1 ## DW_FORM_addr
.byte 18 ## DW_AT_high_pc
.byte 6 ## DW_FORM_data4
.byte 3 ## DW_AT_name
.byte 37 ## DW_FORM_strx1
.byte 27 ## DW_AT_comp_dir
.byte 37 ## DW_FORM_strx1
.byte 114 ## DW_AT_str_offsets_base
.byte 23 ## DW_FORM_sec_offset
.byte 0 ## EOM(1)
.section __DWARF,__debug_info,regular,debug
.set Lset0, Ldebug_info_end0-Ldebug_info_start0 ## Length of Unit
.long Lset0
Ldebug_info_start0:
.short 5 ## DWARF version number
.byte 1 ## DWARF Unit Type
.byte 8 ## Address Size (in bytes)
.set Lset1, Lsection_abbrev-Lsection_abbrev ## Offset Into Abbrev. Section
.long Lset1
.byte 1 ## Abbrev [1] 0xb:0x48 DW_TAG_compile_unit
.quad Lfunc_begin0 ## DW_AT_low_pc
.set Lset3, Lfunc_end0-Lfunc_begin0 ## DW_AT_high_pc
.long Lset3
.byte 0 ## DW_AT_name
.byte 1 ## DW_AT_comp_dir
.set Lset4, Lstr_offsets_base0-Lsection_str_off ## DW_AT_str_offsets_base
.long Lset4
.byte 0 ## End Of Children Mark
Ldebug_info_end0: