Add a Microsoft Demangler.

This adds initial support for a demangling library (LLVMDemangle)
and tool (llvm-undname) for demangling Microsoft names.  This
doesn't cover 100% of cases and there are some known limitations
which I intend to address in followup patches, at least until such
time that we have (near) 100% test coverage matching up with all
of the test cases in clang/test/CodeGenCXX/mangle-ms-*.

Differential Revision: https://reviews.llvm.org/D49552

llvm-svn: 337584

4 files changed, 111 insertions, 0 deletions

diff --git a/llvm/tools/LLVMBuild.txt b/llvm/tools/LLVMBuild.txt
index 5dea5b44048..1732ea0cb8a 100644
--- a/llvm/tools/LLVMBuild.txt
+++ b/llvm/tools/LLVMBuild.txt
@@ -50,6 +50,7 @@ subdirectories =
  llvm-rtdyld
  llvm-size
  llvm-split
+ llvm-undname
  opt
  verify-uselistorder
 
diff --git a/llvm/tools/llvm-undname/CMakeLists.txt b/llvm/tools/llvm-undname/CMakeLists.txt
new file mode 100644
index 00000000000..062f0052597
--- /dev/null
+++ b/llvm/tools/llvm-undname/CMakeLists.txt
@@ -0,0 +1,8 @@
+set(LLVM_LINK_COMPONENTS
+  Demangle
+  Support
+  )
+
+add_llvm_tool(llvm-undname
+  llvm-undname.cpp
+  )
diff --git a/llvm/tools/llvm-undname/LLVMBuild.txt b/llvm/tools/llvm-undname/LLVMBuild.txt
new file mode 100644
index 00000000000..6e598f888ff
--- /dev/null
+++ b/llvm/tools/llvm-undname/LLVMBuild.txt
@@ -0,0 +1,23 @@
+;===- ./tools/llvm-undname/LLVMBuild.txt -----------------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Tool
+name = llvm-undname
+parent = Tools
+required_libraries = Demangle Support
+
diff --git a/llvm/tools/llvm-undname/llvm-undname.cpp b/llvm/tools/llvm-undname/llvm-undname.cpp
new file mode 100644
index 00000000000..f4c09f57505
--- /dev/null
+++ b/llvm/tools/llvm-undname/llvm-undname.cpp
@@ -0,0 +1,79 @@
+//===-- llvm-undname.cpp - Microsoft ABI name undecorator
+//------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This utility works like the windows undname utility. It converts mangled
+// Microsoft symbol names into pretty C/C++ human-readable names.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Demangle/Demangle.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/InitLLVM.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cstdio>
+#include <cstring>
+#include <iostream>
+#include <string>
+
+using namespace llvm;
+
+cl::list<std::string> Symbols(cl::Positional, cl::desc("<input symbols>"),
+                              cl::ZeroOrMore);
+
+static void demangle(const std::string &S) {
+  int Status;
+  char *ResultBuf = microsoftDemangle(S.c_str(), nullptr, nullptr, &Status);
+  if (Status == llvm::demangle_success) {
+    outs() << ResultBuf << "\n";
+    outs().flush();
+  } else {
+    errs() << "Error: Invalid mangled name\n";
+  }
+  std::free(ResultBuf);
+};
+
+int main(int argc, char **argv) {
+  InitLLVM X(argc, argv);
+
+  cl::ParseCommandLineOptions(argc, argv, "llvm-undname\n");
+
+  if (Symbols.empty()) {
+    while (true) {
+      std::string LineStr;
+      std::getline(std::cin, LineStr);
+      if (std::cin.eof())
+        break;
+
+      StringRef Line(LineStr);
+      Line = Line.trim();
+      if (Line.empty() || Line.startswith("#") || Line.startswith(";"))
+        continue;
+
+      // If the user is manually typing in these decorated names, don't echo
+      // them to the terminal a second time.  If they're coming from redirected
+      // input, however, then we should display the input line so that the
+      // mangled and demangled name can be easily correlated in the output.
+      if (!sys::Process::StandardInIsUserInput())
+        outs() << Line << "\n";
+      demangle(Line);
+      outs() << "\n";
+    }
+  } else {
+    for (StringRef S : Symbols) {
+      outs() << S << "\n";
+      demangle(S);
+      outs() << "\n";
+    }
+  }
+
+  return 0;
+}
\ No newline at end of file