[Driver] Suggest correctly spelled driver options

[modocache]

Summary

Depends on https://reviews.llvm.org/D41732.

Utilities such as opt, when invoked with arguments that are very
nearly spelled correctly, suggest the correctly spelled options:

bin/opt -hel
opt: Unknown command line argument '-hel'.  Try: 'bin/opt -help'
opt: Did you mean '-help'?

Clang, on the other hand, prior to this commit, does not:

bin/clang -hel
clang-6.0: error: unknown argument: '-hel'

This commit makes use of the new libLLVMOption API from
https://reviews.llvm.org/D41732 in order to provide correct suggestions:

bin/clang -hel
clang-6.0: error: unknown argument: '-hel', did you mean '-help'?

Test Plan: check-clang

[jroelofs]

lib/Driver/Driver.cpp

191

No need for this variable.

218

Likewise.

[bruno]

This is great!

I assume it also works for cc1 invocations, right? Can you also add a test for %clang_cc1?

[modocache]

Thank you, @bruno! Good idea, I'll add a -cc1 invocation test.

lib/Driver/Driver.cpp

191

There's a call below to Diags.getDiagnosticsLevel, which takes this ID as an argument. Are you suggesting I leave that line alone, and have it use the diagnostic level of err_drv_unsupported_opt, even if err_drv_unsupported_opt_with_suggestion is actually emitted here? That seems reasonable to me, but just want to make sure that's what you had in mind.

[modocache]

Add 'did you mean' suggestions for -cc1 invocations as well.

[jroelofs]

lib/Driver/Driver.cpp

191

Oh, I didn't see that use... never mind.

[v.g.vassilev]

test/Frontend/unknown-arg.c

3 ↗

(On Diff #128681)

Could we also make sure that things passed with -Xclang are also handled?

[modocache]

Test -Xclang as well. Thanks, @v.g.vassilev!

[bruno]

Thanks! LGTM.

include/clang/Basic/DiagnosticDriverKinds.td

 //==--- DiagnosticDriverKinds.td - libdriver diagnostics ------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 let Component = "Driver" in {
 
 def err_drv_no_such_file : Error<"no such file or directory: '%0'">;
 def err_drv_unsupported_opt : Error<"unsupported option '%0'">;
+def err_drv_unsupported_opt_with_suggestion
+  : Error<"unsupported option '%0', did you mean '%1'?">;
 def err_drv_unsupported_opt_for_target : Error<
   "unsupported option '%0' for target '%1'">;
 def err_drv_unsupported_option_argument : Error<
   "unsupported argument '%1' to option '%0'">;
 def err_drv_unknown_stdin_type : Error<
   "-E or -x required when input is from standard input">;
 def err_drv_unknown_stdin_type_clang_cl : Error<
   "use /Tc or /Tp to set input type for standard input">;

 def err_cpu_unsupported_isa
   : Error<"CPU '%0' does not support '%1' execution mode">;
 def err_arch_unsupported_isa
   : Error<"Architecture '%0' does not support '%1' execution mode">;
 
 def err_drv_I_dash_not_supported : Error<
   "'%0' not supported, please use -iquote instead">;
 def err_drv_unknown_argument : Error<"unknown argument: '%0'">;
+def err_drv_unknown_argument_with_suggestion
+  : Error<"unknown argument '%0', did you mean '%1'?">;
 def warn_drv_unknown_argument_clang_cl : Warning<
   "unknown argument ignored in clang-cl: '%0'">,
   InGroup<UnknownArgument>;
+def warn_drv_unknown_argument_clang_cl_with_suggestion : Warning<
+  "unknown argument ignored in clang-cl '%0' (did you mean '%1'?)">,
+  InGroup<UnknownArgument>;
 
 def warn_drv_ycyu_no_arg_clang_cl : Warning<
   "support for '%0' without a filename not implemented yet; flag ignored">,
   InGroup<ClangClPch>;
 def warn_drv_ycyu_different_arg_clang_cl : Warning<
   "support for '/Yc' and '/Yu' with different filenames not implemented yet; flags ignored">,
   InGroup<ClangClPch>;
 def warn_drv_ycyu_no_fi_arg_clang_cl : Warning<

lib/Driver/Driver.cpp

if (MissingArgCount) {
     ContainsError |=
         Diags.getDiagnosticLevel(diag::err_drv_missing_argument,
                                  SourceLocation()) > DiagnosticsEngine::Warning;
   }
 
   // Check for unsupported options.
   for (const Arg *A : Args) {
     if (A->getOption().hasFlag(options::Unsupported)) {
-      Diag(diag::err_drv_unsupported_opt) << A->getAsString(Args);
-      ContainsError |= Diags.getDiagnosticLevel(diag::err_drv_unsupported_opt,
-                                                SourceLocation()) >
+      unsigned DiagID;
+      auto ArgString = A->getAsString(Args);
+      std::string Nearest;
+      if (getOpts().findNearest(
+            ArgString, Nearest, IncludedFlagsBitmask,
+            ExcludedFlagsBitmask | options::Unsupported) > 1) {
+        DiagID = diag::err_drv_unsupported_opt;
+        Diag(DiagID) << ArgString;
+      } else {
+        DiagID = diag::err_drv_unsupported_opt_with_suggestion;
+        Diag(DiagID) << ArgString << Nearest;
+      }
+      ContainsError |= Diags.getDiagnosticLevel(DiagID, SourceLocation()) >
                        DiagnosticsEngine::Warning;
       continue;
     }
 
     // Warn about -mcpu= without an argument.
     if (A->getOption().matches(options::OPT_mcpu_EQ) && A->containsValue("")) {
       Diag(diag::warn_drv_empty_joined_argument) << A->getAsString(Args);
       ContainsError |= Diags.getDiagnosticLevel(
                            diag::warn_drv_empty_joined_argument,
                            SourceLocation()) > DiagnosticsEngine::Warning;
     }
   }
 
   for (const Arg *A : Args.filtered(options::OPT_UNKNOWN)) {
-    auto ID = IsCLMode() ? diag::warn_drv_unknown_argument_clang_cl
+    unsigned DiagID;
+    auto ArgString = A->getAsString(Args);
+    std::string Nearest;
+    if (getOpts().findNearest(
+          ArgString, Nearest, IncludedFlagsBitmask, ExcludedFlagsBitmask) > 1) {
+      DiagID = IsCLMode() ? diag::warn_drv_unknown_argument_clang_cl
                           : diag::err_drv_unknown_argument;
-
-    Diags.Report(ID) << A->getAsString(Args);
-    ContainsError |= Diags.getDiagnosticLevel(ID, SourceLocation()) >
+      Diags.Report(DiagID) << ArgString;
+    } else {
+      DiagID = IsCLMode() ? diag::warn_drv_unknown_argument_clang_cl_with_suggestion
+                          : diag::err_drv_unknown_argument_with_suggestion;
+      Diags.Report(DiagID) << ArgString << Nearest;
+    }
+    ContainsError |= Diags.getDiagnosticLevel(DiagID, SourceLocation()) >
                      DiagnosticsEngine::Warning;
   }
 
   return Args;
 }
 
 // Determine which compilation mode we are in. We look for options which
 // affect the phase, starting with the earliest phases, and record which

test/Driver/unknown-arg.c

 // RUN: not %clang %s -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -### 2>&1 | \
 // RUN: FileCheck %s
+// RUN: not %clang %s -stdlibs=foo -hell -### 2>&1 | \
+// RUN: FileCheck %s --check-prefix=DID-YOU-MEAN
 // RUN: %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -### -c -- %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=CL
+// RUN: %clang_cl -Brepo -### -- %s 2>&1 | \
+// RUN: FileCheck %s --check-prefix=CL-DID-YOU-MEAN
 // RUN: not %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -c -Werror=unknown-argument -### -- %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=CL-ERROR
+// RUN: not %clang_cl -helo -Werror=unknown-argument -### -- %s 2>&1 | \
+// RUN: FileCheck %s --check-prefix=CL-ERROR-DID-YOU-MEAN
 // RUN: %clang_cl -cake-is-lie -%0 -%d -HHHH -munknown-to-clang-option -print-stats -funknown-to-clang-option -c -Wno-unknown-argument -### -- %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=SILENT
 
 // CHECK: error: unknown argument: '-cake-is-lie'
 // CHECK: error: unknown argument: '-%0'
 // CHECK: error: unknown argument: '-%d'
 // CHECK: error: unknown argument: '-HHHH'
 // CHECK: error: unknown argument: '-munknown-to-clang-option'
 // CHECK: error: unknown argument: '-print-stats'
 // CHECK: error: unknown argument: '-funknown-to-clang-option'
+// DID-YOU-MEAN: error: unknown argument '-stdlibs=foo', did you mean '-stdlib=foo'?
+// DID-YOU-MEAN: error: unknown argument '-hell', did you mean '-help'?
 // CL: warning: unknown argument ignored in clang-cl: '-cake-is-lie'
 // CL: warning: unknown argument ignored in clang-cl: '-%0'
 // CL: warning: unknown argument ignored in clang-cl: '-%d'
 // CL: warning: unknown argument ignored in clang-cl: '-HHHH'
 // CL: warning: unknown argument ignored in clang-cl: '-munknown-to-clang-option'
 // CL: warning: unknown argument ignored in clang-cl: '-print-stats'
 // CL: warning: unknown argument ignored in clang-cl: '-funknown-to-clang-option'
+// CL-DID-YOU-MEAN: warning: unknown argument ignored in clang-cl '-Brepo' (did you mean '-Brepro'?)
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-cake-is-lie'
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-%0'
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-%d'
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-HHHH'
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-munknown-to-clang-option'
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-print-stats'
 // CL-ERROR: error: unknown argument ignored in clang-cl: '-funknown-to-clang-option'
+// CL-ERROR-DID-YOU-MEAN: error: unknown argument ignored in clang-cl '-helo' (did you mean '-help'?)
 // SILENT-NOT: error:
 // SILENT-NOT: warning:
 
 
 // RUN: %clang -S %s -o %t.s  -Wunknown-to-clang-option 2>&1 | FileCheck --check-prefix=IGNORED %s
 
 // IGNORED: warning: unknown warning option '-Wunknown-to-clang-option'

test/Driver/unsupported-option.c

+// RUN: not %clang %s --hedonism -### 2>&1 | \
+// RUN: FileCheck %s
+// RUN: not %clang %s --hell -### 2>&1 | \
+// RUN: FileCheck %s --check-prefix=DID-YOU-MEAN
+
+// CHECK: error: unsupported option '--hedonism'
+// DID-YOU-MEAN: error: unsupported option '--hell', did you mean '--help'?