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

3 files changed, 118 insertions, 0 deletions

diff --git a/tools/llvm-dwarfdump/CMakeLists.txt b/tools/llvm-dwarfdump/CMakeLists.txt
new file mode 100644
index 0000000..05aad3f
--- /dev/null
+++ b/tools/llvm-dwarfdump/CMakeLists.txt
@@ -0,0 +1,8 @@
+set(LLVM_LINK_COMPONENTS
+  DebugInfo
+  Object
+  )
+
+add_llvm_tool(llvm-dwarfdump
+  llvm-dwarfdump.cpp
+  )
diff --git a/tools/llvm-dwarfdump/Makefile b/tools/llvm-dwarfdump/Makefile
new file mode 100644
index 0000000..e61f27d
--- /dev/null
+++ b/tools/llvm-dwarfdump/Makefile
@@ -0,0 +1,17 @@
+##===- tools/llvm-dwarfdump/Makefile -----------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+
+TOOLNAME = llvm-dwarfdump
+LINK_COMPONENTS = DebugInfo Object
+
+# This tool has no plugins, optimize startup time.
+TOOL_NO_EXPORTS = 1
+
+include $(LEVEL)/Makefile.common
diff --git a/tools/llvm-dwarfdump/llvm-dwarfdump.cpp b/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
new file mode 100644
index 0000000..cf8b4d08
--- /dev/null
+++ b/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
@@ -0,0 +1,93 @@
+//===-- llvm-dwarfdump.cpp - Debug info dumping utility for llvm -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This program is a utility that works like "dwarfdump".
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/DebugInfo/DIContext.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/MemoryObject.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+#include <algorithm>
+#include <cstring>
+using namespace llvm;
+using namespace object;
+
+static cl::list<std::string>
+InputFilenames(cl::Positional, cl::desc("<input object files>"),
+               cl::ZeroOrMore);
+
+static void DumpInput(const StringRef &Filename) {
+  OwningPtr<MemoryBuffer> Buff;
+
+  if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
+    errs() << Filename << ": " << ec.message() << "\n";
+    return;
+  }
+
+  OwningPtr<ObjectFile> Obj(ObjectFile::createObjectFile(Buff.take()));
+
+  outs() << '\n';
+  outs() << Filename
+         << ":\tfile format " << Obj->getFileFormatName() << "\n\n";
+
+  StringRef DebugInfoSection;
+  StringRef DebugAbbrevSection;
+  StringRef DebugLineSection;
+
+  error_code ec;
+  for (ObjectFile::section_iterator i = Obj->begin_sections(),
+                                    e = Obj->end_sections();
+                                    i != e; i.increment(ec)) {
+    StringRef name;
+    i->getName(name);
+    StringRef data;
+    i->getContents(data);
+    if (name.endswith("debug_info"))
+      DebugInfoSection = data;
+    else if (name.endswith("debug_abbrev"))
+      DebugAbbrevSection = data;
+    else if (name.endswith("debug_line"))
+      DebugLineSection = data;
+  }
+
+  OwningPtr<DIContext> dictx(DIContext::getDWARFContext(/*FIXME*/true,
+                                                        DebugInfoSection,
+                                                        DebugAbbrevSection));
+  dictx->dump(outs());
+}
+
+int main(int argc, char **argv) {
+  // Print a stack trace if we signal out.
+  sys::PrintStackTraceOnErrorSignal();
+  PrettyStackTraceProgram X(argc, argv);
+  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  cl::ParseCommandLineOptions(argc, argv, "llvm dwarf dumper\n");
+
+  // Defaults to a.out if no filenames specified.
+  if (InputFilenames.size() == 0)
+    InputFilenames.push_back("a.out");
+
+  std::for_each(InputFilenames.begin(), InputFilenames.end(), DumpInput);
+
+  return 0;
+}