Sketch out a DWARF parser.
This introduces a new library to LLVM: libDebugInfo. It will provide debug information
parsing to LLVM. Much of the design and some of the code is taken from the LLDB project.
It also contains an llvm-dwarfdump tool that can dump the abbrevs and DIEs from an
object file. It can be used to write tests for DWARF input and output easily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139627 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFCompileUnit.h b/lib/DebugInfo/DWARFCompileUnit.h
new file mode 100644
index 0000000..0c082ad
--- /dev/null
+++ b/lib/DebugInfo/DWARFCompileUnit.h
@@ -0,0 +1,98 @@
+//===-- DWARFCompileUnit.h --------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARFCOMPILEUNIT_H
+#define LLVM_DEBUGINFO_DWARFCOMPILEUNIT_H
+
+#include "DWARFDebugAbbrev.h"
+#include "DWARFDebugInfoEntry.h"
+#include <vector>
+
+namespace llvm {
+
+class DWARFContext;
+class raw_ostream;
+
+class DWARFCompileUnit {
+ DWARFContext &Context;
+
+ uint32_t Offset;
+ uint32_t Length;
+ uint16_t Version;
+ const DWARFAbbreviationDeclarationSet *Abbrevs;
+ uint8_t AddrSize;
+ uint64_t BaseAddr;
+ // The compile unit debug information entry item.
+ std::vector<DWARFDebugInfoEntryMinimal> DieArray;
+public:
+ DWARFCompileUnit(DWARFContext &context) : Context(context) {
+ clear();
+ }
+
+ DWARFContext &getContext() const { return Context; }
+ DataExtractor getDebugInfoExtractor() const;
+
+ bool extract(DataExtractor debug_info, uint32_t* offset_ptr);
+ uint32_t extract(uint32_t offset, DataExtractor debug_info_data,
+ const DWARFAbbreviationDeclarationSet *abbrevs);
+
+ /// extractDIEsIfNeeded - Parses a compile unit and indexes its DIEs if it
+ /// hasn't already been done.
+ size_t extractDIEsIfNeeded(bool cu_die_only);
+ void clear();
+ void dump(raw_ostream &OS);
+ uint32_t getOffset() const { return Offset; }
+ /// Size in bytes of the compile unit header.
+ uint32_t getSize() const { return 11; }
+ bool containsDIEOffset(uint32_t die_offset) const {
+ return die_offset >= getFirstDIEOffset() &&
+ die_offset < getNextCompileUnitOffset();
+ }
+ uint32_t getFirstDIEOffset() const { return Offset + getSize(); }
+ uint32_t getNextCompileUnitOffset() const { return Offset + Length + 4; }
+ /// Size in bytes of the .debug_info data associated with this compile unit.
+ size_t getDebugInfoSize() const { return Length + 4 - getSize(); }
+ uint32_t getLength() const { return Length; }
+ uint16_t getVersion() const { return Version; }
+ const DWARFAbbreviationDeclarationSet *getAbbreviations() const {
+ return Abbrevs;
+ }
+ uint8_t getAddressByteSize() const { return AddrSize; }
+ uint64_t getBaseAddress() const { return BaseAddr; }
+
+ void setBaseAddress(uint64_t base_addr) {
+ BaseAddr = base_addr;
+ }
+
+ /// setDIERelations - We read in all of the DIE entries into our flat list
+ /// of DIE entries and now we need to go back through all of them and set the
+ /// parent, sibling and child pointers for quick DIE navigation.
+ void setDIERelations();
+
+ void addDIE(DWARFDebugInfoEntryMinimal &die) {
+ // The average bytes per DIE entry has been seen to be
+ // around 14-20 so lets pre-reserve the needed memory for
+ // our DIE entries accordingly. Search forward for "Compute
+ // average bytes per DIE" to see #if'ed out code that does
+ // that determination.
+
+ // Only reserve the memory if we are adding children of
+ // the main compile unit DIE. The compile unit DIE is always
+ // the first entry, so if our size is 1, then we are adding
+ // the first compile unit child DIE and should reserve
+ // the memory.
+ if (DieArray.empty())
+ DieArray.reserve(getDebugInfoSize() / 14);
+ DieArray.push_back(die);
+ }
+};
+
+}
+
+#endif