Use zlib to uncompress debug sections in DWARF parser.
This makes llvm-dwarfdump and llvm-symbolizer understand
debug info sections compressed by ld.gold linker.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180088 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFContext.cpp b/lib/DebugInfo/DWARFContext.cpp
index 74a8c36..1e13731 100644
--- a/lib/DebugInfo/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARFContext.cpp
@@ -10,6 +10,8 @@
#include "DWARFContext.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Compression.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/Path.h"
@@ -483,6 +485,22 @@
return InliningInfo;
}
+static bool consumeCompressedDebugSectionHeader(StringRef &data,
+ uint64_t &OriginalSize) {
+ // Consume "ZLIB" prefix.
+ if (!data.startswith("ZLIB"))
+ return false;
+ data = data.substr(4);
+ // Consume uncompressed section size (big-endian 8 bytes).
+ DataExtractor extractor(data, false, 8);
+ uint32_t Offset = 0;
+ OriginalSize = extractor.getU64(&Offset);
+ if (Offset == 0)
+ return false;
+ data = data.substr(Offset);
+ return true;
+}
+
DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
IsLittleEndian(Obj->isLittleEndian()),
AddressSize(Obj->getBytesInAddress()) {
@@ -497,6 +515,22 @@
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))
+ continue;
+ OwningPtr<MemoryBuffer> UncompressedSection;
+ if (zlib::uncompress(data, UncompressedSection, OriginalSize) !=
+ zlib::StatusOK)
+ continue;
+ // Make data point to uncompressed section contents and save its contents.
+ name = name.substr(1);
+ data = UncompressedSection->getBuffer();
+ UncompressedSections.push_back(UncompressedSection.take());
+ }
+
StringRef *Section = StringSwitch<StringRef*>(name)
.Case("debug_info", &InfoSection)
.Case("debug_abbrev", &AbbrevSection)
@@ -584,4 +618,8 @@
}
}
+DWARFContextInMemory::~DWARFContextInMemory() {
+ DeleteContainerPointers(UncompressedSections);
+}
+
void DWARFContextInMemory::anchor() { }