Author: Fangrui Song Date: 2023-11-17T01:13:38-08:00 New Revision: 76a441a6efa5b7e73d96a3d67512493f3873b1cb
URL: https://github.com/llvm/llvm-project/commit/76a441a6efa5b7e73d96a3d67512493f3873b1cb DIFF: https://github.com/llvm/llvm-project/commit/76a441a6efa5b7e73d96a3d67512493f3873b1cb.diff LOG: [MC] Fix compression header size check in ELF writer This is #66888 with a test. For MC we only use a zstd test, as zlib has a lot of versions/forks with different speed/size tradeoff, which would make the test more brittle. If clang/test/Misc/cc1as-compress.s turns out to be brittle, we could make the string longer. Added: Modified: clang/test/Misc/cc1as-compress.s llvm/lib/MC/ELFObjectWriter.cpp llvm/test/MC/ELF/compress-debug-sections-zstd.s Removed: ################################################################################ diff --git a/clang/test/Misc/cc1as-compress.s b/clang/test/Misc/cc1as-compress.s index 54563c33bd165cb..4c81c5ca0f7f26f 100644 --- a/clang/test/Misc/cc1as-compress.s +++ b/clang/test/Misc/cc1as-compress.s @@ -12,4 +12,4 @@ // ZSTD: 0000 02000000 00000000 .section .debug_str,"MS",@progbits,1 -.asciz "perfectly compressable data sample *****************************************" +.asciz "perfectly compressable data sample ******************************************" diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp index 8490fefe7ff5351..e4d18d8a7dd5b54 100644 --- a/llvm/lib/MC/ELFObjectWriter.cpp +++ b/llvm/lib/MC/ELFObjectWriter.cpp @@ -843,7 +843,7 @@ bool ELFWriter::maybeWriteCompression( uint32_t ChType, uint64_t Size, SmallVectorImpl<uint8_t> &CompressedContents, Align Alignment) { uint64_t HdrSize = - is64Bit() ? sizeof(ELF::Elf32_Chdr) : sizeof(ELF::Elf64_Chdr); + is64Bit() ? sizeof(ELF::Elf64_Chdr) : sizeof(ELF::Elf32_Chdr); if (Size <= HdrSize + CompressedContents.size()) return false; // Platform specific header is followed by compressed data. diff --git a/llvm/test/MC/ELF/compress-debug-sections-zstd.s b/llvm/test/MC/ELF/compress-debug-sections-zstd.s index 01ae21a2b8abb7b..a05c5015728156a 100644 --- a/llvm/test/MC/ELF/compress-debug-sections-zstd.s +++ b/llvm/test/MC/ELF/compress-debug-sections-zstd.s @@ -10,7 +10,8 @@ # SEC: .debug_line PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 00 C 0 0 8 # SEC: .debug_abbrev PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 00 0 0 1 # SEC: .debug_info PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 00 0 0 1 -# SEC: .debug_str PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 01 MSC 0 0 8 +## .debug_str is uncompressed becuase sizeof(Elf64_Chdr)+len(compressed) >= len(uncompressed). +# SEC: .debug_str PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 01 MS 0 0 1 # SEC: .debug_frame PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 00 C 0 0 8 # CHECK: Contents of section .debug_line @@ -23,6 +24,12 @@ # RUN: llvm-objcopy --decompress-debug-sections %t %t.decom # RUN: cmp %t.uncom %t.decom +## .debug_str is compressed becuase sizeof(Elf32_Chdr)+len(compressed) < len(uncompressed). +# RUN: llvm-mc -filetype=obj -triple=i386 --defsym I386=1 -compress-debug-sections=zstd --defsym LONG=1 %s -o %t1 +# RUN: llvm-readelf -S %t1 | FileCheck %s --check-prefix=SEC1 + +# SEC1: .debug_str PROGBITS [[#%x,]] [[#%x,]] [[#%x,]] 01 MSC 0 0 4 + ## Don't compress a section not named .debug_*. .section .nonalloc,"",@progbits .rept 50 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
