[Driver] Report available language standards on user error

[idlecode]

Summary

In case user did not provide valid standard name for -std option,
available values (with short description) will be reported.

To test: clang -std=iso3103 -c source.c

[ahatanak]

Test case?

lib/Frontend/CompilerInvocation.cpp

1709

Is it possible to change the diagnostic so that it's easier to tell which part is the supported value and which part is the description?

The diagnostic looks like this, and I found it a little hard to tell at a quick glance:

"c89 - ISO C 1990"

[idlecode]

Added test, changed printout style a bit (but this still needs to be checked)

[idlecode]

Indeed, thanks :)
I ran make check-all and had no errors so I thought there are no tests.

lib/Frontend/CompilerInvocation.cpp

1709

Sure, I have tried few formats with quotes/colons but how about this (a bit verbose) version:

note: supported values are:
note: 'c89' for standard 'ISO C 1990'
note: 'c90' for standard 'ISO C 1990'
note: 'iso9899:1990' for standard 'ISO C 1990'
...

What do you think about it? Do you have any suggestions?

[rsmith]

include/clang/Basic/DiagnosticDriverKinds.td

233

Please remove this note and instead add "use " to the start of the next note. (That is more consistent with how we add notes to other diagnostics.)

lib/Frontend/CompilerInvocation.cpp

1709

We should probably suppress the notes for standards that aren't applicable to the current language.

[idlecode]

Displayed standards will now match processed file kind

[rsmith]

lib/Frontend/CompilerInvocation.cpp

1703–1704

{ on previous line, please, and indent the previous two lines to match the (.

[idlecode]

Addressed Richard's inline comment.

[rsmith]

LGTM, do you need someone to commit for you?

[idlecode]

Yes, please.
Thanks for you time :)

[rsmith]

Committed as r295113.

[idlecode]

Committed as r295113

include/clang/Basic/DiagnosticDriverKinds.td

def warn_drv_disabling_vptr_no_rtti_default : Warning<
   InGroup<DiagGroup<"auto-disable-vptr-sanitizer">>;
 
 def note_drv_command_failed_diag_msg : Note<
   "diagnostic msg: %0">;
 def note_drv_t_option_is_global : Note<
   "The last /TC or /TP option takes precedence over earlier instances">;
 def note_drv_address_sanitizer_debug_runtime : Note<
   "AddressSanitizer doesn't support linking with debug runtime libraries yet">;
+def note_drv_supported_values : Note<"supported values are:">;
+def note_drv_supported_value_with_description : Note<"'%0' for standard '%1'">;
 
 def err_analyzer_config_no_value : Error<
   "analyzer-config option '%0' has a key but no value">;
 def err_analyzer_config_multiple_values : Error<
   "analyzer-config option '%0' should contain only one '='">;
 
 def err_drv_modules_validate_once_requires_timestamp : Error<
   "option '-fmodules-validate-once-per-build-session' requires "

lib/Frontend/CompilerInvocation.cpp

static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   if (const Arg *A = Args.getLastArg(OPT_std_EQ)) {
     LangStd = llvm::StringSwitch<LangStandard::Kind>(A->getValue())
 #define LANGSTANDARD(id, name, desc, features) \
       .Case(name, LangStandard::lang_##id)
 #define LANGSTANDARD_ALIAS(id, alias) \
       .Case(alias, LangStandard::lang_##id)
 #include "clang/Frontend/LangStandards.def"
       .Default(LangStandard::lang_unspecified);
-    if (LangStd == LangStandard::lang_unspecified)
+    if (LangStd == LangStandard::lang_unspecified) {
       Diags.Report(diag::err_drv_invalid_value)
         << A->getAsString(Args) << A->getValue();
-    else {
+      // Report all supported standards with description.
+      Diags.Report(diag::note_drv_supported_values);
+      for (unsigned KindValue = 0;
+          KindValue != LangStandard::lang_unspecified;
+          ++KindValue)
+      {
+        const LangStandard &Std = LangStandard::getLangStandardForKind(
+          static_cast<LangStandard::Kind>(KindValue));
+        Diags.Report(diag::note_drv_supported_value_with_description)
+          << Std.getName() << Std.getDescription();
+      }
+    } else {
       // Valid standard, check to make sure language and standard are
       // compatible.
       const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
       switch (IK) {
       case IK_C:
       case IK_ObjC:
       case IK_PreprocessedC:
       case IK_PreprocessedObjC:

test/Driver/unknown-std.c

+// RUN: not %clang %s -std=foobar -c 2>&1 | \
+// RUN: FileCheck %s
+
+// CHECK: error: invalid value 'foobar' in '-std=foobar'
+// CHECK: note: supported values are:
+// CHECK: note: 'c89' for standard 'ISO C 1990'
+// CHECK: note: 'c90' for standard 'ISO C 1990'
+// CHECK: note: 'iso9899:1990' for standard 'ISO C 1990'
+// CHECK: note: 'iso9899:199409' for standard 'ISO C 1990 with amendment 1'
+// CHECK: note: 'gnu89' for standard 'ISO C 1990 with GNU extensions'
+// CHECK: note: 'gnu90' for standard 'ISO C 1990 with GNU extensions'
+// CHECK: note: 'c99' for standard 'ISO C 1999'
+// CHECK: note: 'c9x' for standard 'ISO C 1999'
+// CHECK: note: 'iso9899:1999' for standard 'ISO C 1999'
+// CHECK: note: 'iso9899:199x' for standard 'ISO C 1999'
+// CHECK: note: 'gnu99' for standard 'ISO C 1999 with GNU extensions'
+// CHECK: note: 'gnu9x' for standard 'ISO C 1999 with GNU extensions'
+// CHECK: note: 'c11' for standard 'ISO C 2011'
+// CHECK: note: 'c1x' for standard 'ISO C 2011'
+// CHECK: note: 'iso9899:2011' for standard 'ISO C 2011'
+// CHECK: note: 'iso9899:201x' for standard 'ISO C 2011'
+// CHECK: note: 'gnu11' for standard 'ISO C 2011 with GNU extensions'
+// CHECK: note: 'gnu1x' for standard 'ISO C 2011 with GNU extensions'
+// CHECK: note: 'c++98' for standard 'ISO C++ 1998 with amendments'
+// CHECK: note: 'c++03' for standard 'ISO C++ 1998 with amendments'
+// CHECK: note: 'gnu++98' for standard 'ISO C++ 1998 with amendments and GNU extensions'
+// CHECK: note: 'c++0x' for standard 'ISO C++ 2011 with amendments'
+// CHECK: note: 'c++11' for standard 'ISO C++ 2011 with amendments'
+// CHECK: note: 'gnu++0x' for standard 'ISO C++ 2011 with amendments and GNU extensions'
+// CHECK: note: 'gnu++11' for standard 'ISO C++ 2011 with amendments and GNU extensions'
+// CHECK: note: 'c++1y' for standard 'ISO C++ 2014 with amendments'
+// CHECK: note: 'c++14' for standard 'ISO C++ 2014 with amendments'
+// CHECK: note: 'gnu++1y' for standard 'ISO C++ 2014 with amendments and GNU extensions'
+// CHECK: note: 'gnu++14' for standard 'ISO C++ 2014 with amendments and GNU extensions'
+// CHECK: note: 'c++1z' for standard 'Working draft for ISO C++ 2017'
+// CHECK: note: 'gnu++1z' for standard 'Working draft for ISO C++ 2017 with GNU extensions'
+// CHECK: note: 'cl' for standard 'OpenCL 1.0'
+// CHECK: note: 'cl1.1' for standard 'OpenCL 1.1'
+// CHECK: note: 'cl1.2' for standard 'OpenCL 1.2'
+// CHECK: note: 'cl2.0' for standard 'OpenCL 2.0'
+// CHECK: note: 'cuda' for standard 'NVIDIA CUDA(tm)'
+