[flang][driver] Make --version and -version consistent with clang

[ekieri]

Summary

This patch makes -version valid, and --version invalid, for
flang-new -fc1. The invocation

flang-new --version

remains valid. This behaviour is consistent with clang
(and with clang -cc1 and clang -cc1as).

Previously, flang-new -fc1 accepted --version (as per Options.td), but
the frontend driver acutally checks for -version. As a result,

flang-new -fc1 --version

triggered no action, emitted no message, and stalled waiting for
standard input.

Fixes #51438

[PeteSteinfeld]

Looks good.

Thanks for doing this, Emil!

[awarzynski]

Makes sense, many thanks for doing this!

clang/include/clang/Driver/Options.td

5758

[nit] IMHO this file lacks comments, hence the suggestion :)

[ekieri]

Address review comment.
Fix typo in summary.

[ekieri]

clang/include/clang/Driver/Options.td

5758

Sure!

On the topic of this file's structure, I found the nested "let Flags" quite confusing -- Setting "Flags" inside "def version" does not work, as it would be overwritten by the outer "let Flags" on line 4820. But that is a different patch.

[awarzynski]

clang/include/clang/Driver/Options.td

5758

On the topic of this file's structure, I found the nested "let Flags" quite confusing -- Setting "Flags" inside "def version" does not work, as it would be overwritten by the outer "let Flags" on line 4820. But that is a different patch.

Fixing that is high on my TODO list, just never high enough :( Happy to review if you get a chance to prepare something! ;-)

clang/include/clang/Driver/Options.td

 def _profile : Flag<["--"], "profile">, Alias<p>;
 def _resource_EQ : Joined<["--"], "resource=">, Alias<fcompile_resource_EQ>;
 def _resource : Separate<["--"], "resource">, Alias<fcompile_resource_EQ>;
 def _rtlib : Separate<["--"], "rtlib">, Alias<rtlib_EQ>;
 def _serialize_diags : Separate<["-", "--"], "serialize-diagnostics">, Flags<[NoXarchOption]>,
   HelpText<"Serialize compiler diagnostics to a file">;
 // We give --version different semantics from -version.
 def _version : Flag<["--"], "version">,
-  Flags<[CoreOption, FC1Option, FlangOption]>,
+  Flags<[CoreOption, FlangOption]>,
   HelpText<"Print version information">;
 def _signed_char : Flag<["--"], "signed-char">, Alias<fsigned_char>;
 def _std : Separate<["--"], "std">, Alias<std_EQ>;
 def _stdlib : Separate<["--"], "stdlib">, Alias<stdlib_EQ>;
 def _sysroot_EQ : Joined<["--"], "sysroot=">;
 def _sysroot : Separate<["--"], "sysroot">, Alias<_sysroot_EQ>;
 def _target_help : Flag<["--"], "target-help">;
 def _trace_includes : Flag<["--"], "trace-includes">, Alias<H>;
def aligned_alloc_unavailable : Flag<["-"], "faligned-alloc-unavailable">,
   HelpText<"Aligned allocation/deallocation functions are unavailable">,
   MarshallingInfoFlag<LangOpts<"AlignedAllocationUnavailable">>,
   ShouldParseIf<faligned_allocation.KeyPath>;
 
 //===----------------------------------------------------------------------===//
 // Language Options
 //===----------------------------------------------------------------------===//
 
-let Flags = [CC1Option, CC1AsOption, NoDriverOption] in {
+let Flags = [CC1Option, CC1AsOption, FC1Option, NoDriverOption] in {
 
 def version : Flag<["-"], "version">,
   HelpText<"Print the compiler version">,
   MarshallingInfoFlag<FrontendOpts<"ShowVersion">>;
+
+} // let Flags = [CC1Option, CC1AsOption, FC1Option, NoDriverOption]
+
+let Flags = [CC1Option, CC1AsOption, NoDriverOption] in {
+
 def main_file_name : Separate<["-"], "main-file-name">,
   HelpText<"Main file name to use for debug info and source if missing">,
   MarshallingInfoString<CodeGenOpts<"MainFileName">>;
 def split_dwarf_output : Separate<["-"], "split-dwarf-output">,
   HelpText<"File name to use for split dwarf debug info output">,
   MarshallingInfoString<CodeGenOpts<"SplitDwarfOutput">>;
 
 }

flang/test/Driver/driver-help.f90

 ! HELP-FC1-NEXT: -pedantic              Warn on language extensions
 ! HELP-FC1-NEXT: -plugin <name>         Use the named plugin action instead of the default action (use "help" to list available options)
 ! HELP-FC1-NEXT: -P                     Disable linemarker output in -E mode
 ! HELP-FC1-NEXT: -std=<value>           Language standard to compile for
 ! HELP-FC1-NEXT: -S                     Only run preprocess and compilation steps
 ! HELP-FC1-NEXT: -test-io               Run the InputOuputTest action. Use for development and testing only.
 ! HELP-FC1-NEXT: -triple <value>        Specify target triple (e.g. i686-apple-darwin9)
 ! HELP-FC1-NEXT: -U <macro>             Undefine macro <macro>
-! HELP-FC1-NEXT: --version              Print version information
+! HELP-FC1-NEXT: -version               Print the compiler version
 ! HELP-FC1-NEXT: -W<warning>            Enable the specified warning
 
 !---------------
 ! EXPECTED ERROR
 !---------------
 ! ERROR: error: unknown argument '-helps'; did you mean '-help'

flang/test/Driver/driver-version.f90

 
 !-----------
 ! RUN LINES
 !-----------
-! RUN: %flang --version 2>&1 | FileCheck %s
+! RUN: %flang --version 2>&1 | FileCheck %s --check-prefix=VERSION
 ! RUN: not %flang --versions 2>&1 | FileCheck %s --check-prefix=ERROR
+! RUN: %flang_fc1 -version 2>&1 | FileCheck %s --check-prefix=VERSION-FC1
+! RUN: not %flang_fc1 --version 2>&1 | FileCheck %s --check-prefix=ERROR-FC1
 
 !-----------------------
 ! EXPECTED OUTPUT
 !-----------------------
-! CHECK: flang-new version
-! CHECK-NEXT: Target:
-! CHECK-NEXT: Thread model:
-! CHECK-NEXT: InstalledDir:
+! VERSION: flang-new version
+! VERSION-NEXT: Target:
+! VERSION-NEXT: Thread model:
+! VERSION-NEXT: InstalledDir:
 
 ! ERROR: flang-new: error: unsupported option '--versions'; did you mean '--version'?
+
+! VERSION-FC1: LLVM version
+
+! ERROR-FC1: error: unknown argument '--version'; did you mean '-version'?