[flang] Produce proper "preprocessor output" for -E option

Rename the current -E option to "-E -Xflang -fno-reformat".

Add a new Parsing::EmitPreprocessedSource() routine to convert the
cooked character stream output of the prescanner back to something
more closely resembling output from a traditional preprocessor;
call this new routine when -E appears.

The new -E output is suitable for use as fixed form Fortran source to
compilation by (one hopes) any Fortran compiler.  If the original
top-level source file had been free form source, the output will be
suitable for use as free form source as well; otherwise there may be
diagnostics about missing spaces if they were indeed absent in the
original fixed form source.

Unless the -P option appears, #line directives are interspersed
with the output (but be advised, f18 will ignore these if presented
with them in a later compilation).

An effort has been made to preserve original alphabetic character case
and source indentation.

Add -P and -fno-reformat to the new drivers.

Tweak test options to avoid confusion with prior -E output; use
-fno-reformat where needed, but prefer to keep -E, sometimes
in concert with -P, on most, updating expected results accordingly.

Differential Revision: https://reviews.llvm.org/D106727

1 files changed, 0 insertions, 18 deletions

diff --git a/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index 243e251..9c3b13b6 100644
--- a/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -28,61 +28,43 @@ static std::unique_ptr<FrontendAction> CreateFrontendBaseAction(
   switch (ak) {
   case InputOutputTest:
     return std::make_unique<InputOutputTestAction>();
-    break;
   case PrintPreprocessedInput:
     return std::make_unique<PrintPreprocessedAction>();
-    break;
   case ParseSyntaxOnly:
     return std::make_unique<ParseSyntaxOnlyAction>();
   case EmitObj:
     return std::make_unique<EmitObjAction>();
-    break;
   case DebugUnparse:
     return std::make_unique<DebugUnparseAction>();
-    break;
   case DebugUnparseNoSema:
     return std::make_unique<DebugUnparseNoSemaAction>();
-    break;
   case DebugUnparseWithSymbols:
     return std::make_unique<DebugUnparseWithSymbolsAction>();
-    break;
   case DebugDumpSymbols:
     return std::make_unique<DebugDumpSymbolsAction>();
-    break;
   case DebugDumpParseTree:
     return std::make_unique<DebugDumpParseTreeAction>();
-    break;
   case DebugDumpParseTreeNoSema:
     return std::make_unique<DebugDumpParseTreeNoSemaAction>();
-    break;
   case DebugDumpAll:
     return std::make_unique<DebugDumpAllAction>();
-    break;
   case DebugDumpProvenance:
     return std::make_unique<DebugDumpProvenanceAction>();
-    break;
   case DebugDumpParsingLog:
     return std::make_unique<DebugDumpParsingLogAction>();
-    break;
   case DebugMeasureParseTree:
     return std::make_unique<DebugMeasureParseTreeAction>();
-    break;
   case DebugPreFIRTree:
     return std::make_unique<DebugPreFIRTreeAction>();
-    break;
   case GetDefinition:
     return std::make_unique<GetDefinitionAction>();
-    break;
   case GetSymbolsSources:
     return std::make_unique<GetSymbolsSourcesAction>();
-    break;
   case InitOnly:
     return std::make_unique<InitOnlyAction>();
-    break;
   default:
     break;
     // TODO:
-    // case RunPreprocessor:
     // case ParserSyntaxOnly:
     // case EmitLLVM:
     // case EmitLLVMOnly: