[llvm] r270540 - [llvm-dwarfdump] - Teach dwarfdump to decompress debug sections in zlib style.
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Tue May 24 02:28:37 PDT 2016
Author: grimar
Date: Tue May 24 04:28:36 2016
New Revision: 270540
URL: http://llvm.org/viewvc/llvm-project?rev=270540&view=rev
Log:
[llvm-dwarfdump] - Teach dwarfdump to decompress debug sections in zlib style.
Before this llvm-dwarfdump only recognized zlib-gnu compression style of headers,
this patch adds support for zlib style.
It looks reasonable to support both styles for dumping,
even if we are not going to suport generating of deprecated gnu one.
Differential revision: http://reviews.llvm.org/D20470
Added:
llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlibgnu.elf-x86-64 (with props)
Modified:
llvm/trunk/include/llvm/Object/COFF.h
llvm/trunk/include/llvm/Object/ELFObjectFile.h
llvm/trunk/include/llvm/Object/MachO.h
llvm/trunk/include/llvm/Object/ObjectFile.h
llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp
llvm/trunk/lib/Object/COFFObjectFile.cpp
llvm/trunk/lib/Object/MachOObjectFile.cpp
llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlib.cc
llvm/trunk/test/DebugInfo/dwarfdump-zlib.test
Modified: llvm/trunk/include/llvm/Object/COFF.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/COFF.h?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/COFF.h (original)
+++ llvm/trunk/include/llvm/Object/COFF.h Tue May 24 04:28:36 2016
@@ -694,6 +694,7 @@ protected:
std::error_code getSectionContents(DataRefImpl Sec,
StringRef &Res) const override;
uint64_t getSectionAlignment(DataRefImpl Sec) const override;
+ bool isSectionCompressed(DataRefImpl Sec) const override;
bool isSectionText(DataRefImpl Sec) const override;
bool isSectionData(DataRefImpl Sec) const override;
bool isSectionBSS(DataRefImpl Sec) const override;
Modified: llvm/trunk/include/llvm/Object/ELFObjectFile.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ELFObjectFile.h?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ELFObjectFile.h (original)
+++ llvm/trunk/include/llvm/Object/ELFObjectFile.h Tue May 24 04:28:36 2016
@@ -222,6 +222,7 @@ protected:
std::error_code getSectionContents(DataRefImpl Sec,
StringRef &Res) const override;
uint64_t getSectionAlignment(DataRefImpl Sec) const override;
+ bool isSectionCompressed(DataRefImpl Sec) const override;
bool isSectionText(DataRefImpl Sec) const override;
bool isSectionData(DataRefImpl Sec) const override;
bool isSectionBSS(DataRefImpl Sec) const override;
@@ -584,6 +585,11 @@ uint64_t ELFObjectFile<ELFT>::getSection
}
template <class ELFT>
+bool ELFObjectFile<ELFT>::isSectionCompressed(DataRefImpl Sec) const {
+ return getSection(Sec)->sh_flags & ELF::SHF_COMPRESSED;
+}
+
+template <class ELFT>
bool ELFObjectFile<ELFT>::isSectionText(DataRefImpl Sec) const {
return getSection(Sec)->sh_flags & ELF::SHF_EXECINSTR;
}
Modified: llvm/trunk/include/llvm/Object/MachO.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/MachO.h?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/MachO.h (original)
+++ llvm/trunk/include/llvm/Object/MachO.h Tue May 24 04:28:36 2016
@@ -222,6 +222,7 @@ public:
std::error_code getSectionContents(DataRefImpl Sec,
StringRef &Res) const override;
uint64_t getSectionAlignment(DataRefImpl Sec) const override;
+ bool isSectionCompressed(DataRefImpl Sec) const override;
bool isSectionText(DataRefImpl Sec) const override;
bool isSectionData(DataRefImpl Sec) const override;
bool isSectionBSS(DataRefImpl Sec) const override;
Modified: llvm/trunk/include/llvm/Object/ObjectFile.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ObjectFile.h?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ObjectFile.h (original)
+++ llvm/trunk/include/llvm/Object/ObjectFile.h Tue May 24 04:28:36 2016
@@ -89,6 +89,7 @@ public:
/// @brief Get the alignment of this section as the actual value (not log 2).
uint64_t getAlignment() const;
+ bool isCompressed() const;
bool isText() const;
bool isData() const;
bool isBSS() const;
@@ -214,6 +215,7 @@ protected:
virtual std::error_code getSectionContents(DataRefImpl Sec,
StringRef &Res) const = 0;
virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
+ virtual bool isSectionCompressed(DataRefImpl Sec) const = 0;
virtual bool isSectionText(DataRefImpl Sec) const = 0;
virtual bool isSectionData(DataRefImpl Sec) const = 0;
virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
@@ -380,6 +382,10 @@ inline uint64_t SectionRef::getAlignment
return OwningObject->getSectionAlignment(SectionPimpl);
}
+inline bool SectionRef::isCompressed() const {
+ return OwningObject->isSectionCompressed(SectionPimpl);
+}
+
inline bool SectionRef::isText() const {
return OwningObject->isSectionText(SectionPimpl);
}
Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFContext.cpp Tue May 24 04:28:36 2016
@@ -15,6 +15,7 @@
#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/ELF.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
@@ -590,8 +591,8 @@ DWARFContext::getInliningInfoForAddress(
return InliningInfo;
}
-static bool consumeCompressedDebugSectionHeader(StringRef &data,
- uint64_t &OriginalSize) {
+static bool consumeCompressedGnuHeader(StringRef &data,
+ uint64_t &OriginalSize) {
// Consume "ZLIB" prefix.
if (!data.startswith("ZLIB"))
return false;
@@ -606,6 +607,50 @@ static bool consumeCompressedDebugSectio
return true;
}
+static bool consumeCompressedZLibHeader(StringRef &Data, uint64_t &OriginalSize,
+ bool IsLE, bool Is64Bit) {
+ using namespace ELF;
+ uint64_t HdrSize = Is64Bit ? sizeof(Elf64_Chdr) : sizeof(Elf32_Chdr);
+ if (Data.size() < HdrSize)
+ return false;
+
+ DataExtractor Extractor(Data, IsLE, 0);
+ uint32_t Offset = 0;
+ if (Extractor.getUnsigned(&Offset, Is64Bit ? sizeof(Elf64_Word)
+ : sizeof(Elf32_Word)) !=
+ ELFCOMPRESS_ZLIB)
+ return false;
+
+ // Skip Elf64_Chdr::ch_reserved field.
+ if (Is64Bit)
+ Offset += sizeof(Elf64_Word);
+
+ OriginalSize = Extractor.getUnsigned(&Offset, Is64Bit ? sizeof(Elf64_Xword)
+ : sizeof(Elf32_Word));
+ Data = Data.substr(HdrSize);
+ return true;
+}
+
+static bool tryDecompress(StringRef &Name, StringRef &Data,
+ SmallString<32> &Out, bool ZLibStyle, bool IsLE,
+ bool Is64Bit) {
+ if (!zlib::isAvailable())
+ return false;
+
+ uint64_t OriginalSize;
+ bool Result =
+ ZLibStyle ? consumeCompressedZLibHeader(Data, OriginalSize, IsLE, Is64Bit)
+ : consumeCompressedGnuHeader(Data, OriginalSize);
+
+ if (!Result || zlib::uncompress(Data, Out, OriginalSize) != zlib::StatusOK)
+ return false;
+
+ // gnu-style names are started from "z", consume that.
+ if (!ZLibStyle)
+ Name = Name.substr(1);
+ return true;
+}
+
DWARFContextInMemory::DWARFContextInMemory(const object::ObjectFile &Obj,
const LoadedObjectInfo *L)
: IsLittleEndian(Obj.isLittleEndian()),
@@ -631,20 +676,13 @@ DWARFContextInMemory::DWARFContextInMemo
name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
- // Check if debug info section is compressed with zlib.
- if (name.startswith("zdebug_")) {
- uint64_t OriginalSize;
- if (!zlib::isAvailable() ||
- !consumeCompressedDebugSectionHeader(data, OriginalSize))
+ bool ZLibStyleCompressed = Section.isCompressed();
+ if (ZLibStyleCompressed || name.startswith("zdebug_")) {
+ SmallString<32> Out;
+ if (!tryDecompress(name, data, Out, ZLibStyleCompressed, IsLittleEndian,
+ AddressSize == 8))
continue;
- UncompressedSections.resize(UncompressedSections.size() + 1);
- if (zlib::uncompress(data, UncompressedSections.back(), OriginalSize) !=
- zlib::StatusOK) {
- UncompressedSections.pop_back();
- continue;
- }
- // Make data point to uncompressed section contents and save its contents.
- name = name.substr(1);
+ UncompressedSections.emplace_back(std::move(Out));
data = UncompressedSections.back();
}
Modified: llvm/trunk/lib/Object/COFFObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/COFFObjectFile.cpp?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/lib/Object/COFFObjectFile.cpp (original)
+++ llvm/trunk/lib/Object/COFFObjectFile.cpp Tue May 24 04:28:36 2016
@@ -292,6 +292,10 @@ uint64_t COFFObjectFile::getSectionAlign
return Sec->getAlignment();
}
+bool COFFObjectFile::isSectionCompressed(DataRefImpl Sec) const {
+ return false;
+}
+
bool COFFObjectFile::isSectionText(DataRefImpl Ref) const {
const coff_section *Sec = toSec(Ref);
return Sec->Characteristics & COFF::IMAGE_SCN_CNT_CODE;
Modified: llvm/trunk/lib/Object/MachOObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/MachOObjectFile.cpp?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/lib/Object/MachOObjectFile.cpp (original)
+++ llvm/trunk/lib/Object/MachOObjectFile.cpp Tue May 24 04:28:36 2016
@@ -653,6 +653,10 @@ uint64_t MachOObjectFile::getSectionAlig
return uint64_t(1) << Align;
}
+bool MachOObjectFile::isSectionCompressed(DataRefImpl Sec) const {
+ return false;
+}
+
bool MachOObjectFile::isSectionText(DataRefImpl Sec) const {
uint32_t Flags = getSectionFlags(this, Sec);
return Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
Modified: llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlib.cc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlib.cc?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlib.cc (original)
+++ llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlib.cc Tue May 24 04:28:36 2016
@@ -16,9 +16,11 @@ int main() {
return f(2, 3);
}
-// Built with Clang 3.2 and ld.gold linker:
+// Built with Clang 3.9 and GNU gold (GNU Binutils for Ubuntu 2.26) 1.11:
// $ mkdir -p /tmp/dbginfo
// $ cp dwarfdump-test-zlib.cc /tmp/dbginfo
// $ cd /tmp/dbginfo
-// $ clang++ -g dwarfdump-test-zlib.cc -Wl,--compress-debug-sections=zlib \
-// -o <output>
+// $ clang++ -g dwarfdump-test-zlib.cc -Wl,--compress-debug-sections=zlib -o dwarfdump-test-zlib.elf-x86-64
+// $ clang++ -g dwarfdump-test-zlib.cc -Wl,--compress-debug-sections=zlib-gnu -o dwarfdump-test-zlibgnu.elf-x86-64
+// llvm-readobj -sections can be used to see that outputs really contain the compressed sections, also output in both
+// cases is slightly smaller, that is because of compression.
\ No newline at end of file
Added: llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlibgnu.elf-x86-64
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlibgnu.elf-x86-64?rev=270540&view=auto
==============================================================================
Binary file - no diff available.
Propchange: llvm/trunk/test/DebugInfo/Inputs/dwarfdump-test-zlibgnu.elf-x86-64
------------------------------------------------------------------------------
svn:mime-type = application/octet-stream
Modified: llvm/trunk/test/DebugInfo/dwarfdump-zlib.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/dwarfdump-zlib.test?rev=270540&r1=270539&r2=270540&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/dwarfdump-zlib.test (original)
+++ llvm/trunk/test/DebugInfo/dwarfdump-zlib.test Tue May 24 04:28:36 2016
@@ -1,6 +1,12 @@
REQUIRES: zlib
RUN: llvm-dwarfdump %p/Inputs/dwarfdump-test-zlib.elf-x86-64 | FileCheck %s
+RUN: llvm-dwarfdump %p/Inputs/dwarfdump-test-zlibgnu.elf-x86-64 | FileCheck %s
CHECK: .debug_abbrev contents
+
+// Dump content of a little section to check that both zlib and zlib gnu styles do
+// the decompression correctly and result is the same. This and above also checks
+// that sections names are properly shown in zlib-gnu style (without additional 'z' prefix).
CHECK: .debug_info contents
+CHECK: 0x00000000: Compile Unit: length = 0x00000144 version = 0x0004 abbr_offset = 0x0000 addr_size = 0x08 (next unit at 0x00000148)
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