diff options
| -rw-r--r-- | lib/MC/ELFObjectWriter.cpp | 8 | ||||
| -rw-r--r-- | test/MC/ELF/compression.s | 45 |
2 files changed, 37 insertions, 16 deletions
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index c064e24128..de05501756 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -1209,10 +1209,12 @@ getUncompressedData(MCAsmLayout &Layout, // Include the debug info compression header: // "ZLIB" followed by 8 bytes representing the uncompressed size of the section, // useful for consumers to preallocate a buffer to decompress into. -static void +static bool prependCompressionHeader(uint64_t Size, SmallVectorImpl<char> &CompressedContents) { static const StringRef Magic = "ZLIB"; + if (Size <= Magic.size() + sizeof(Size) + CompressedContents.size()) + return false; if (sys::IsLittleEndianHost) Size = sys::SwapByteOrder(Size); CompressedContents.insert(CompressedContents.begin(), @@ -1221,6 +1223,7 @@ prependCompressionHeader(uint64_t Size, std::copy(reinterpret_cast<char *>(&Size), reinterpret_cast<char *>(&Size + 1), CompressedContents.begin() + Magic.size()); + return true; } // Return a single fragment containing the compressed contents of the whole @@ -1243,7 +1246,8 @@ getCompressedFragment(MCAsmLayout &Layout, if (Success != zlib::StatusOK) return nullptr; - prependCompressionHeader(UncompressedData.size(), CompressedContents); + if (!prependCompressionHeader(UncompressedData.size(), CompressedContents)) + return nullptr; return CompressedFragment; } diff --git a/test/MC/ELF/compression.s b/test/MC/ELF/compression.s index 65f920c092..07b689eef1 100644 --- a/test/MC/ELF/compression.s +++ b/test/MC/ELF/compression.s @@ -1,6 +1,6 @@ // RUN: llvm-mc -filetype=obj -compress-debug-sections -triple x86_64-pc-linux-gnu < %s -o %t // RUN: llvm-objdump -s %t | FileCheck %s -// RUN: llvm-dwarfdump -debug-dump=abbrev %t | FileCheck --check-prefix=ABBREV %s +// RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck --check-prefix=INFO %s // RUN: llvm-mc -filetype=obj -compress-debug-sections -triple i386-pc-linux-gnu < %s \ // RUN: | llvm-readobj -symbols - | FileCheck --check-prefix=386-SYMBOLS %s @@ -12,8 +12,12 @@ // CHECK-NOT: ZLIB // CHECK: Contents of -// CHECK: Contents of section .zdebug_abbrev: -// CHECK-NEXT: ZLIB +// Don't compress small sections, such as this simple debug_abbrev example +// CHECK: Contents of section .debug_abbrev: +// CHECK-NOT: ZLIB +// CHECK-NOT: Contents of + +// CHECK: Contents of section .debug_info: // FIXME: Handle compressing alignment fragments to support compressing debug_frame // CHECK: Contents of section .debug_frame: @@ -21,8 +25,7 @@ // CHECK: Contents of // Decompress one valid dwarf section just to check that this roundtrips -// ABBREV: Abbrev table for offset: 0x00000000 -// ABBREV: [1] DW_TAG_compile_unit DW_CHILDREN_no +// INFO: 0x00000000: Compile Unit: length = 0x0000000c version = 0x0004 abbr_offset = 0x0000 addr_size = 0x08 (next unit at 0x00000010) // In x86 32 bit named symbols are used for temporary symbols in merge // sections, so make sure we handle symbols inside compressed sections @@ -41,23 +44,37 @@ .byte 14 # DW_FORM_strp .byte 0 # EOM(1) .byte 0 # EOM(2) + + .section .debug_info,"",@progbits + .long 12 # Length of Unit + .short 4 # DWARF version number + .long .Lsection_abbrev # Offset Into Abbrev. Section + .byte 8 # Address Size (in bytes) + .byte 1 # Abbrev [1] DW_TAG_compile_unit + .long .Linfo_string0 # DW_AT_comp_dir + .text foo: .cfi_startproc .file 1 "Driver.ii" +# pad out the line table to make sure it's big enough to warrant compression .loc 1 2 0 nop + .loc 1 3 0 + nop + .loc 1 4 0 + nop + .loc 1 5 0 + nop + .loc 1 6 0 + nop + .loc 1 7 0 + nop + .loc 1 8 0 + nop .cfi_endproc .cfi_sections .debug_frame .section .debug_str,"MS",@progbits,1 .Linfo_string0: - .asciz "foo" - - .section .debug_info,"",@progbits - .long 40 # Length of Unit - .short 4 # DWARF version number - .long .Lsection_abbrev # Offset Into Abbrev. Section - .byte 4 # Address Size (in bytes) - .byte 1 # Abbrev [1] DW_TAG_compile_unit - .long .Linfo_string0 # DW_AT_comp_dir + .asciz "compress this " |