[llvm-symbolizer] Add back --version and add a -v alias

[MaskRay]

Summary

The switch from llvm::cl to OptTable (D83530) dropped --version, which
is needed by some users.

This patch also adds a -v alias, which is available in GNU addr2line.

The version dumping is similar to llvm-objcopy --version (exotic):

llvm-symbolizer
LLVM (http://llvm.org/):
  LLVM version 12.0.0git
  Optimized build with assertions.
  Default target: x86_64-unknown-linux-gnu
  Host CPU: skylake-avx512

[dyung]

Looks good, thanks for fixing this for us!

[jhenderson]

You should add the short alias to the rst docs, same as other short aliases.

Aside from that and the inline comment, LGTM.

llvm/test/tools/llvm-symbolizer/version.test

4

It probably makes sense to test the -v alias for llvm-symbolizer too, I reckon. Since we're adding support for it, we don't want to drop the alias in the future probably.

[MaskRay]

Test llvm-symbolizer -v

Add -v to llvm-symbolizer.rst

llvm/docs/CommandGuide/llvm-symbolizer.rst

Function start line: 9
       Line: 11
       Column: 18
     main
       Filename: /tmp/test.cpp
     Function start line: 14
       Line: 15
       Column: 0
 
-.. option:: --version
+.. option:: --version, -v
 
   Print version information for the tool.
 
 .. option:: @<FILE>
 
   Read command-line options from response file `<FILE>`.
 
 MACH-O SPECIFIC OPTIONS

llvm/test/tools/llvm-symbolizer/version.test

+# RUN: llvm-symbolizer --version | FileCheck %s --check-prefixes=SYMBOLIZER,COMMON
+# RUN: llvm-symbolizer -v | FileCheck %s --check-prefixes=SYMBOLIZER,COMMON
+# RUN: llvm-addr2line --version | FileCheck %s --check-prefixes=ADDR2LINE,COMMON
+# RUN: llvm-addr2line -v | FileCheck %s --check-prefixes=ADDR2LINE,COMMON
+
+# SYMBOLIZER: llvm-symbolizer{{$}}
+# ADDR2LINE:  llvm-addr2line{{$}}
+# COMMON: LLVM version {{.*}}

llvm/tools/llvm-symbolizer/Opts.td

: Eq<"output-style", "Specify print style. Supported styles: LLVM, GNU">,
       Values<"LLVM,GNU">;
 def pretty_print : F<"pretty-print", "Make the output more human friendly">;
 defm print_source_context_lines : Eq<"print-source-context-lines", "Print N lines of source file context">;
 def relative_address : F<"relative-address", "Interpret addresses as addresses relative to the image base">;
 def relativenames : F<"relativenames", "Strip the compilation directory from paths">;
 defm untag_addresses : B<"untag-addresses", "", "Remove memory tags from addresses before symbolization">;
 def use_native_pdb_reader : F<"use-native-pdb-reader", "Use native PDB functionality">;
 def verbose : F<"verbose", "Print verbose line info">;
+def version : F<"version", "Display the version">;
 
 def : Flag<["-"], "a">, Alias<addresses>, HelpText<"Alias for --addresses">;
 def : F<"print-address", "Alias for --addresses">, Alias<addresses>;
 def : Flag<["-"], "C">, Alias<demangle>, HelpText<"Alias for --demangle">;
 def : Joined<["--"], "exe=">, Alias<obj_EQ>, HelpText<"Alias for --obj">, MetaVarName<"<file>">;
 def : Separate<["--"], "exe">, Alias<obj_EQ>, HelpText<"Alias for --obj">, MetaVarName<"<file>">;
 def : JoinedOrSeparate<["-"], "e">, Alias<obj_EQ>, HelpText<"Alias for --obj">, MetaVarName<"<file>">;
 def : Joined<["-"], "e=">, Alias<obj_EQ>, HelpText<"Alias for --obj">, MetaVarName<"<file>">;
 def : Flag<["-"], "f">, Alias<functions>, HelpText<"Alias for --functions">;
 def : Joined<["-"], "f=">, Alias<functions_EQ>, HelpText<"Alias for --functions=">;
 def : Flag<["-"], "h">, Alias<help>;
 def : Flag<["-"], "i">, Alias<inlines>, HelpText<"Alias for --inlines">;
 def : F<"inlining", "Alias for --inlines">, Alias<inlines>;
 def : Flag<["-"], "p">, Alias<pretty_print>, HelpText<"Alias for --pretty-print">;
 def : Flag<["-"], "s">, Alias<basenames>, HelpText<"Alias for --basenames">;
+def : Flag<["-"], "v">, Alias<version>, HelpText<"Alias for --version">;
 
 // Compatibility aliases for old asan_symbolize.py and sanitizer binaries (before 2020-08).
 def : Flag<["--"], "inlining=true">, Alias<inlines>, HelpText<"Alias for --inlines">;
 def : Flag<["--"], "inlining=false">, Alias<no_inlines>, HelpText<"Alias for --no-inlines">;
 // Compatibility aliases for pprof's symbolizer.
 def : Flag<["-"], "demangle=true">, Alias<demangle>, HelpText<"Alias for --demangle">;
 def : Flag<["-"], "demangle=false">, Alias<no_demangle>, HelpText<"Alias for --no-demangle">;

llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp

if (Cmd == Command::Data) {
     auto ResOrErr = Symbolizer.symbolizeCode(
         ModuleName, {Offset, object::SectionedAddress::UndefSection});
     Printer << (error(ResOrErr) ? DILineInfo() : ResOrErr.get());
   }
   if (OutputStyle == DIPrinter::OutputStyle::LLVM)
     outs() << "\n";
 }
 
-static void printHelp(bool IsAddr2Line, const SymbolizerOptTable &Tbl,
+static void printHelp(StringRef ToolName, const SymbolizerOptTable &Tbl,
                       raw_ostream &OS) {
-  StringRef ToolName = IsAddr2Line ? "llvm-addr2line" : "llvm-symbolizer";
   const char HelpText[] = " [options] addresses...";
   Tbl.PrintHelp(OS, (ToolName + HelpText).str().c_str(),
                 ToolName.str().c_str());
   // TODO Replace this with OptTable API once it adds extrahelp support.
   OS << "\nPass @FILE as argument to read options from FILE.\n";
 }
 
 static opt::InputArgList parseOptions(int Argc, char *Argv[], bool IsAddr2Line,
                                       StringSaver &Saver,
                                       SymbolizerOptTable &Tbl) {
+  StringRef ToolName = IsAddr2Line ? "llvm-addr2line" : "llvm-symbolizer";
   Tbl.setGroupedShortOptions(true);
   // The environment variable specifies initial options which can be overridden
   // by commnad line options.
   Tbl.setInitialOptionsFromEnvironment(IsAddr2Line ? "LLVM_ADDR2LINE_OPTS"
                                                    : "LLVM_SYMBOLIZER_OPTS");
   bool HasError = false;
   opt::InputArgList Args =
       Tbl.parseArgs(Argc, Argv, OPT_UNKNOWN, Saver, [&](StringRef Msg) {
         errs() << ("error: " + Msg + "\n");
         HasError = true;
       });
   if (HasError)
     exit(1);
   if (Args.hasArg(OPT_help)) {
-    printHelp(IsAddr2Line, Tbl, outs());
+    printHelp(ToolName, Tbl, outs());
+    exit(0);
+  }
+  if (Args.hasArg(OPT_version)) {
+    outs() << ToolName << '\n';
+    cl::PrintVersionMessage();
     exit(0);
   }
 
   return Args;
 }
 
 template <typename T>
 static void parseIntArg(const opt::InputArgList &Args, int ID, T &Value) {