[flang] Extended the flang driver options to include gfortran equivalents to pgf90 specific options.

[AlexisPerry]

Summary

Added gfortran equivalents of pgf90's -Mfixed, -Mfree, -Mextend, -Mstandard, -Munlimited and also added -fdefault-double-8

[richard.barton.arm]

This LGTM and was reviewed already under D83488. Happy to approve.

[AlexisPerry]

Correction for handling of OpenMP enabling flags

[richard.barton.arm]

Looks like you needed to squash this into the preivous revision of this patch before submitting? I only see the -fopenmp change now.

[richard.barton.arm]

Timezones are not helping here - I need to clock off for the day. I think revision 1 + revision 2 are correct when combined.

I am happy for you to push the combination of revision 1 and revision 2. I'll approve it on that basis.

[AlexisPerry]

Extended the flang driver options to include gfortran equivalents to pgf90 specific options.

• Added gfortran equivalents of pgf90's -Mfixed, -Mfree, -Mextend, -Mstandard, -Munlimited
• Also added -fdefault-double-8
• Added in a switch to pass through the correct OpenMP-enabling flag depending on if F18_FC=pgf90 or =gfortran

flang/tools/f18/f18.cpp

while (!args.empty()) {
     } else if (arg == "-") {
       fortranSources.push_back("-");
     } else if (arg == "--") {
       while (!args.empty()) {
         fortranSources.emplace_back(std::move(args.front()));
         args.pop_front();
       }
       break;
-    } else if (arg == "-Mfixed") {
+    } else if (arg == "-Mfixed" || arg == "-ffixed-form") {
       driver.forcedForm = true;
       options.isFixedForm = true;
-    } else if (arg == "-Mfree") {
+    } else if (arg == "-Mfree" || arg == "-ffree-form") {
       driver.forcedForm = true;
       options.isFixedForm = false;
-    } else if (arg == "-Mextend") {
+    } else if (arg == "-Mextend" || arg == "-ffixed-line-length-132") {
       options.fixedFormColumns = 132;
-    } else if (arg == "-Munlimited") {
+    } else if (arg == "-Munlimited" || arg == "-ffree-line-length-none" ||
+        arg == "-ffree-line-length-0" || arg == "-ffixed-line-length-none" ||
+        arg == "-ffixed-line-length-0") {
       // For reparsing f18's -E output of fixed-form cooked character stream
       options.fixedFormColumns = 1000000;
     } else if (arg == "-Mbackslash") {
       options.features.Enable(
           Fortran::common::LanguageFeature::BackslashEscapes, false);
     } else if (arg == "-Mnobackslash") {
       options.features.Enable(
           Fortran::common::LanguageFeature::BackslashEscapes, true);
-    } else if (arg == "-Mstandard") {
+    } else if (arg == "-Mstandard" || arg == "-std=f95" ||
+        arg == "-std=f2003" || arg == "-std=f2008" || arg == "-std=legacy") {
       driver.warnOnNonstandardUsage = true;
     } else if (arg == "-fopenmp") {
       options.features.Enable(Fortran::common::LanguageFeature::OpenMP);
       options.predefinitions.emplace_back("_OPENMP", "201511");
     } else if (arg == "-Werror") {
       driver.warningsAreErrors = true;
     } else if (arg == "-ed") {
       options.features.Enable(Fortran::common::LanguageFeature::OldDebugLines);
if (arg.empty()) {
         options.predefinitions.emplace_back(arg.substr(2), "1");
       } else {
         options.predefinitions.emplace_back(
             arg.substr(2, eq - 2), arg.substr(eq + 1));
       }
     } else if (arg.substr(0, 2) == "-U") {
       options.predefinitions.emplace_back(
           arg.substr(2), std::optional<std::string>{});
+    } else if (arg == "-fdefault-double-8") {
+      defaultKinds.set_defaultRealKind(4);
     } else if (arg == "-r8" || arg == "-fdefault-real-8") {
       defaultKinds.set_defaultRealKind(8);
     } else if (arg == "-i8" || arg == "-fdefault-integer-8") {
       defaultKinds.set_defaultIntegerKind(8);
       defaultKinds.set_subscriptIntegerKind(8);
       defaultKinds.set_sizeIntegerKind(8);
     } else if (arg == "-Mlargearray") {
     } else if (arg == "-Mnolargearray") {
if (arg.empty()) {
         args.pop_front();
       }
       driver.getDefinitionArgs = {arguments[0], arguments[1], arguments[2]};
     } else if (arg == "-fget-symbols-sources") {
       driver.getSymbolsSources = true;
     } else if (arg == "-help" || arg == "--help" || arg == "-?") {
       llvm::errs()
           << "f18 options:\n"
-          << "  -Mfixed | -Mfree     force the source form\n"
-          << "  -Mextend             132-column fixed form\n"
+          << "  -Mfixed | -Mfree | -ffixed-form | -ffree-form   force the "
+             "source form\n"
+          << "  -Mextend | -ffixed-line-length-132   132-column fixed form\n"
           << "  -f[no-]backslash     enable[disable] \\escapes in literals\n"
           << "  -M[no]backslash      disable[enable] \\escapes in literals\n"
           << "  -Mstandard           enable conformance warnings\n"
+          << "  -std=<standard>      enable conformance warnings\n"
           << "  -fenable=<feature>   enable a language feature\n"
           << "  -fdisable=<feature>  disable a language feature\n"
-          << "  -r8 | -fdefault-real-8 | -i8 | -fdefault-integer-8  "
-             "change default kinds of intrinsic types\n"
+          << "  -r8 | -fdefault-real-8 | -i8 | -fdefault-integer-8 | "
+             "-fdefault-double-8   change default kinds of intrinsic types\n"
           << "  -Werror              treat warnings as errors\n"
           << "  -ed                  enable fixed form D lines\n"
           << "  -E                   prescan & preprocess only\n"
           << "  -module dir          module output directory (default .)\n"
           << "  -flatin              interpret source as Latin-1 (ISO 8859-1) "
              "rather than UTF-8\n"
           << "  -fparse-only         parse only, no output except messages\n"
           << "  -funparse            parse & reformat only, no code "
if (arg.empty()) {
         driver.searchDirectories.push_back(arg.substr(2));
       }
     }
   }
 
   if (driver.warnOnNonstandardUsage) {
     options.features.WarnOnAllNonstandard();
   }
-  if (options.features.IsEnabled(Fortran::common::LanguageFeature::OpenMP)) {
-    driver.pgf90Args.push_back("-mp");
-  }
   if (isPGF90) {
     if (!options.features.IsEnabled(
             Fortran::common::LanguageFeature::BackslashEscapes)) {
       driver.pgf90Args.push_back(
           "-Mbackslash"); // yes, this *disables* them in pgf90
     }
+    if (options.features.IsEnabled(Fortran::common::LanguageFeature::OpenMP)) {
+      driver.pgf90Args.push_back("-mp");
+    }
+
     Fortran::parser::useHexadecimalEscapeSequences = false;
   } else {
     if (options.features.IsEnabled(
             Fortran::common::LanguageFeature::BackslashEscapes)) {
       driver.pgf90Args.push_back("-fbackslash");
     }
+    if (options.features.IsEnabled(Fortran::common::LanguageFeature::OpenMP)) {
+      driver.pgf90Args.push_back("-fopenmp");
+    }
+
     Fortran::parser::useHexadecimalEscapeSequences = true;
   }
 
   if (!anyFiles) {
     driver.measureTree = true;
     driver.dumpUnparse = true;
     CompileFortran("-", options, driver, defaultKinds);
     return exitStatus;