llvm-project/lld/MachO/Dwarf.cpp
Daniel Bertalan f2c7f75f61 [lld-macho] Support creating N_SO stab for DWARF5 compile units
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
2022-07-28 09:58:26 +02:00

46 lines
1.7 KiB
C++

//===- DWARF.cpp ----------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "Dwarf.h"
#include "InputFiles.h"
#include "InputSection.h"
#include "OutputSegment.h"
#include <memory>
using namespace lld;
using namespace lld::macho;
using namespace llvm;
std::unique_ptr<DwarfObject> DwarfObject::create(ObjFile *obj) {
auto dObj = std::make_unique<DwarfObject>();
bool hasDwarfInfo = false;
// LLD only needs to extract the source file path and line numbers from the
// debug info, so we initialize DwarfObject with just the sections necessary
// to get that path. The debugger will locate the debug info via the object
// file paths that we emit in our STABS symbols, so we don't need to process &
// emit them ourselves.
for (const InputSection *isec : obj->debugSections) {
if (StringRef *s =
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)) {
*s = toStringRef(isec->data);
hasDwarfInfo = true;
}
}
if (hasDwarfInfo)
return dObj;
return nullptr;
}