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/DWARFDebugAbbrev.cpp b/lib/DebugInfo/DWARFDebugAbbrev.cpp
new file mode 100644
index 0000000..68769f0
--- /dev/null
+++ b/lib/DebugInfo/DWARFDebugAbbrev.cpp
@@ -0,0 +1,108 @@
+//===-- DWARFDebugAbbrev.cpp ----------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFDebugAbbrev.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+bool DWARFAbbreviationDeclarationSet::extract(DataExtractor data,
+ uint32_t* offset_ptr) {
+ const uint32_t beginOffset = *offset_ptr;
+ Offset = beginOffset;
+ clear();
+ DWARFAbbreviationDeclaration abbrevDeclaration;
+ uint32_t prevAbbrAode = 0;
+ while (abbrevDeclaration.extract(data, offset_ptr)) {
+ Decls.push_back(abbrevDeclaration);
+ if (IdxOffset == 0) {
+ IdxOffset = abbrevDeclaration.getCode();
+ } else {
+ if (prevAbbrAode + 1 != abbrevDeclaration.getCode())
+ IdxOffset = UINT32_MAX;// Out of order indexes, we can't do O(1) lookups
+ }
+ prevAbbrAode = abbrevDeclaration.getCode();
+ }
+ return beginOffset != *offset_ptr;
+}
+
+
+void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
+ for (unsigned i = 0, e = Decls.size(); i != e; ++i)
+ Decls[i].dump(OS);
+}
+
+
+const DWARFAbbreviationDeclaration*
+DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(uint32_t abbrCode)
+ const {
+ if (IdxOffset == UINT32_MAX) {
+ DWARFAbbreviationDeclarationCollConstIter pos;
+ DWARFAbbreviationDeclarationCollConstIter end = Decls.end();
+ for (pos = Decls.begin(); pos != end; ++pos) {
+ if (pos->getCode() == abbrCode)
+ return &(*pos);
+ }
+ } else {
+ uint32_t idx = abbrCode - IdxOffset;
+ if (idx < Decls.size())
+ return &Decls[idx];
+ }
+ return NULL;
+}
+
+DWARFDebugAbbrev::DWARFDebugAbbrev() :
+ m_abbrevCollMap(),
+ m_prev_abbr_offset_pos(m_abbrevCollMap.end()) {}
+
+
+void DWARFDebugAbbrev::parse(DataExtractor data) {
+ uint32_t offset = 0;
+
+ while (data.isValidOffset(offset)) {
+ uint32_t initial_cu_offset = offset;
+ DWARFAbbreviationDeclarationSet abbrevDeclSet;
+
+ if (abbrevDeclSet.extract(data, &offset))
+ m_abbrevCollMap[initial_cu_offset] = abbrevDeclSet;
+ else
+ break;
+ }
+ m_prev_abbr_offset_pos = m_abbrevCollMap.end();
+}
+
+void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
+ if (m_abbrevCollMap.empty()) {
+ OS << "< EMPTY >\n";
+ return;
+ }
+
+ DWARFAbbreviationDeclarationCollMapConstIter pos;
+ for (pos = m_abbrevCollMap.begin(); pos != m_abbrevCollMap.end(); ++pos) {
+ OS << format("Abbrev table for offset: 0x%8.8x\n", pos->first);
+ pos->second.dump(OS);
+ }
+}
+
+const DWARFAbbreviationDeclarationSet*
+DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t cu_abbr_offset) const {
+ DWARFAbbreviationDeclarationCollMapConstIter end = m_abbrevCollMap.end();
+ DWARFAbbreviationDeclarationCollMapConstIter pos;
+ if (m_prev_abbr_offset_pos != end &&
+ m_prev_abbr_offset_pos->first == cu_abbr_offset) {
+ return &(m_prev_abbr_offset_pos->second);
+ } else {
+ pos = m_abbrevCollMap.find(cu_abbr_offset);
+ m_prev_abbr_offset_pos = pos;
+ }
+
+ if (pos != m_abbrevCollMap.end())
+ return &(pos->second);
+ return NULL;
+}