[LLD] [MinGW] Map the -verbose option, implement -### for showing the produced parameters

[mstorsjo]

Summary

Pass the -verbose option through to the COFF linker, and show the arguments passed to it. If the -### option is specified, just show the produced argument list and exit, just like in clang.

Replace the first argument with "lld-link" in order to produce a correct command line.

[ruiu]

This is what I'm trying to do, but as you already have a patch, please go ahead and submit. LGTM.

I'm rewriting tests so that we verify resulting command lines instead of verifying output files. I'll send you a patch shortly.

MinGW/Driver.cpp

182–184 ↗

(On Diff #114672)

include llvm/ADT/StringExtras.h so that you can do

if (...)
  outs() << llvm::join(LinkArgs, " ") << "\n";

lld/trunk/MinGW/Driver.cpp

 //===- MinGW/Driver.cpp ---------------------------------------------------===//
 //
 //                             The LLVM Linker
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// GNU ld style linker driver for COFF currently supporting mingw-w64.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "lld/Driver/Driver.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/Option.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"

 // then call coff::link.
 bool link(ArrayRef<const char *> ArgsArr, raw_ostream &Diag) {
   COFFLdOptTable Parser;
   opt::InputArgList Args = Parser.parse(ArgsArr.slice(1));
 
   std::vector<std::string> LinkArgs;
   auto Add = [&](const Twine &S) { LinkArgs.push_back(S.str()); };
 
-  Add(ArgsArr[0]);
+  Add("lld-link");
 
   if (auto *A = Args.getLastArg(OPT_entry))
     Add("-entry:" + StringRef(A->getValue()));
   if (auto *A = Args.getLastArg(OPT_subs))
     Add("-subsystem:" + StringRef(A->getValue()));
   if (auto *A = Args.getLastArg(OPT_outlib))
     Add("-implib:" + StringRef(A->getValue()));
   if (auto *A = Args.getLastArg(OPT_stack))
bool link(ArrayRef<const char *> ArgsArr, raw_ostream &Diag) {
 
   for (auto *A : Args.filtered(OPT_INPUT, OPT_l)) {
     if (A->getOption().getUnaliasedOption().getID() == OPT_INPUT)
       Add(A->getValue());
     else
       Add(searchLibrary(A->getValue(), SearchPaths, Args.hasArg(OPT_Bstatic)));
   }
 
+  if (Args.hasArg(OPT_verbose))
+    Add("-verbose");
+
+  if (Args.hasArg(OPT_verbose) || Args.hasArg(OPT__HASH_HASH_HASH))
+    outs() << llvm::join(LinkArgs, " ") << "\n";
+
+  if (Args.hasArg(OPT__HASH_HASH_HASH))
+    return true;
+
   // Repack vector of strings to vector of const char pointers for coff::link.
   std::vector<const char *> Vec;
   for (const std::string &S : LinkArgs)
     Vec.push_back(S.c_str());
   return coff::link(Vec);
 }
 
 } // namespace mingw
 } // namespace lld

lld/trunk/MinGW/Options.td

 def o: JoinedOrSeparate<["-"], "o">, MetaVarName<"<path>">,
   HelpText<"Path to file to write output">;
 def l: JoinedOrSeparate<["-"], "l">, MetaVarName<"<libName>">,
   HelpText<"Root name of library to use">;
 def shared: F<"shared">, HelpText<"Build a shared object">;
 def subs: Separate<["--"], "subsystem">, HelpText<"Specify subsystem">;
 def stack: Separate<["--"], "stack">;
 def outlib: Separate<["--"], "out-implib">, HelpText<"Import library name">;
+def verbose: F<"verbose">, HelpText<"Verbose mode">;
+
+// LLD specific options
+def _HASH_HASH_HASH : Flag<["-"], "###">,
+    HelpText<"Print (but do not run) the commands to run for this compilation">;
 
 // Currently stubs to avoid errors
 def Bdynamic: F<"Bdynamic">, HelpText<"Link against shared libraries">;
 def Bstatic: F<"Bstatic">, HelpText<"Do not link against shared libraries">;
 def major_image_version: Separate<["--"], "major-image-version">;
 def minor_image_version: Separate<["--"], "minor-image-version">;
 def enable_auto_image_base: Flag<["--"], "enable-auto-image-base">;
 def full_shutdown: Flag<["--"], "full-shutdown">;
 def O: Joined<["-"], "O">, HelpText<"Optimize output file size">;
 def v: Flag<["-"], "v">, HelpText<"Display the version number">;
-def verbose: F<"verbose">, HelpText<"Verbose mode">;
 def version: F<"version">, HelpText<"Display the version number and exit">;
 
 // Alias
 def alias_entry_e: JoinedOrSeparate<["-"], "e">, Alias<entry>;

lld/trunk/test/MinGW/driver.s

 # REQEUIRES: x86
 # RUN: rm -f a.exe a.dll
 
 # RUN: llvm-mc -triple=x86_64-windows-msvc %s -filetype=obj -o %t.obj
 # RUN: ld.lld -m i386pep --entry main %t.obj
 # RUN: llvm-readobj a.exe | FileCheck %s
 # RUN: ld.lld -m i386pep -shared --entry main %t.obj
 # RUN: llvm-readobj a.dll | FileCheck %s
 # RUN: ld.lld -m i386pep -e main %t.obj -o %t.exe
 # RUN: llvm-readobj %t.exe | FileCheck %s
 # CHECK: File:
 
+# RUN: ld.lld -m i386pep -e main %t.obj -o %t.exe -verbose -### | FileCheck %s -check-prefix CHECK-VERBOSE
+# CHECK-VERBOSE: lld-link -entry:main
+# CHECK-VERBOSE-SAME: -machine:x64 -alternatename:__image_base__=__ImageBase
+# CHECK-VERBOSE-SAME: -verbose
+
 # RUN: ld.lld -m i386pep --entry main %t.obj -o %t.exe --subsystem console
 # RUN: llvm-readobj -file-headers %t.exe | FileCheck %s -check-prefix CHECK-CONSOLE
 # CHECK-CONSOLE: Subsystem: IMAGE_SUBSYSTEM_WINDOWS_CUI (0x3)
 
 # RUN: ld.lld -m i386pep --entry main %t.obj -o %t.exe --subsystem windows
 # RUN: llvm-readobj -file-headers %t.exe | FileCheck %s -check-prefix CHECK-WINDOWS
 # CHECK-WINDOWS: Subsystem: IMAGE_SUBSYSTEM_WINDOWS_GUI (0x2)