| commit 1ccde533425a4ba9d379510206ad680ff9702129 |
| Author: Fangrui Song <maskray@google.com> |
| Date: Tue Apr 28 18:53:12 2020 -0700 |
| |
| [ELF] --gdb-index: support .debug_loclists |
| |
| --gdb-index currently crashes when reading a translation unit with |
| DWARF v5 .debug_loclists . Call stack: |
| |
| ``` |
| SyntheticSections.cpp GdbIndexSection::create |
| SyntheticSections.cpp readAddressAreas |
| DWARFUnit.cpp DWARFUnit::tryExtractDIEsIfNeeded |
| DWARFListTable.cpp DWARFListTableHeader::extract |
| ... |
| DWARFDataExtractor.cpp DWARFDataExtractor::getRelocatedValue |
| lld/ELF/DWARF.cpp LLDDwarfObj<ELFT>::find (sec.sec is nullptr) |
| ... |
| |
| ``` |
| |
| This patch adds support for .debug_loclists to make `DWARFUnit::tryExtractDIEsIfNeeded` happy. |
| Building --gdb-index does not need .debug_loclists |
| |
| Reviewed By: dblaikie, grimar |
| |
| Differential Revision: https://reviews.llvm.org/D79061 |
| |
| diff --git a/lld/ELF/DWARF.cpp b/lld/ELF/DWARF.cpp |
| index bf4fff76c31..f1587d93e53 100644 |
| --- a/lld/ELF/DWARF.cpp |
| +++ b/lld/ELF/DWARF.cpp |
| @@ -36,6 +36,7 @@ template <class ELFT> LLDDwarfObj<ELFT>::LLDDwarfObj(ObjFile<ELFT> *obj) { |
| .Case(".debug_gnu_pubnames", &gnuPubnamesSection) |
| .Case(".debug_gnu_pubtypes", &gnuPubtypesSection) |
| .Case(".debug_info", &infoSection) |
| + .Case(".debug_loclists", &loclistsSection) |
| .Case(".debug_ranges", &rangesSection) |
| .Case(".debug_rnglists", &rnglistsSection) |
| .Case(".debug_str_offsets", &strOffsetsSection) |
| diff --git a/lld/ELF/DWARF.h b/lld/ELF/DWARF.h |
| index 51ec9092f17..8609e35faf9 100644 |
| --- a/lld/ELF/DWARF.h |
| +++ b/lld/ELF/DWARF.h |
| @@ -32,6 +32,10 @@ public: |
| f(infoSection); |
| } |
| |
| + const llvm::DWARFSection &getLoclistsSection() const override { |
| + return loclistsSection; |
| + } |
| + |
| const llvm::DWARFSection &getRangesSection() const override { |
| return rangesSection; |
| } |
| @@ -81,6 +85,7 @@ private: |
| LLDDWARFSection gnuPubnamesSection; |
| LLDDWARFSection gnuPubtypesSection; |
| LLDDWARFSection infoSection; |
| + LLDDWARFSection loclistsSection; |
| LLDDWARFSection rangesSection; |
| LLDDWARFSection rnglistsSection; |
| LLDDWARFSection strOffsetsSection; |
| diff --git a/lld/test/ELF/gdb-index-loclists.s b/lld/test/ELF/gdb-index-loclists.s |
| new file mode 100644 |
| index 00000000000..e3769b69537 |
| --- /dev/null |
| +++ b/lld/test/ELF/gdb-index-loclists.s |
| @@ -0,0 +1,37 @@ |
| +# REQUIRES: x86 |
| +## Regression test that we don't crash on DWARF v5 .debug_loclists |
| + |
| +# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o |
| +# RUN: ld.lld --gdb-index %t.o -o /dev/null |
| + |
| +.section .debug_abbrev,"",@progbits |
| + .byte 1 # Abbreviation Code |
| + .byte 17 # DW_TAG_compile_unit |
| + .byte 0 # DW_CHILDREN_no |
| + .ascii "\214\001" # DW_AT_loclists_base |
| + .byte 23 # DW_FORM_sec_offset |
| + .byte 0 # EOM(1) |
| + .byte 0 # EOM(2) |
| + .byte 0 |
| + |
| +.section .debug_info,"",@progbits |
| +.Lcu_begin0: |
| + .long .Lcu_end0-.Lcu_begin0-4 # Length of Unit |
| + .short 5 # DWARF version number |
| + .byte 1 # DWARF Unit Type |
| + .byte 8 # Address Size |
| + .long 0 # Offset Into Abbrev. Section |
| + .byte 1 # Abbrev [1] DW_TAG_compile_unit |
| + .long .Lloclists_table_base0 # DW_AT_loclists_base |
| +.Lcu_end0: |
| + |
| +.section .debug_loclists,"",@progbits |
| + .long .Ldebug_loclist_table_end0-.Ldebug_loclist_table_start0 # Length |
| +.Ldebug_loclist_table_start0: |
| + .short 5 # Version |
| + .byte 8 # Address size |
| + .byte 0 # Segment selector size |
| + .long 0 # Offset entry count |
| +.Lloclists_table_base0: |
| + .byte 0 # DW_LLE_end_of_list |
| +.Ldebug_loclist_table_end0: |
