[flang][driver] Add support for `-debug-dump-pft`

[awarzynski]

Summary

This patch adds support for dumping the pre-FIR tree in `flang-new
-fc1`. This flag is functionally identical to -pft-test in bbc.

[clementval]

I’m not sure this is a feature we want to expose in the main driver.

[awarzynski]

In D121198#3366741, @clementval wrote:

I’m not sure this is a feature we want to expose in the main driver.

It would only be available in flang-new -fc1, i.e. the frontend driver. We are not exposing it in flang-new.

[shraiysh]

LGTM.

[clementval]

In D121198#3366774, @awarzynski wrote:

In D121198#3366741, @clementval wrote:

I’m not sure this is a feature we want to expose in the main driver.

It would only be available in flang-new -fc1, i.e. the frontend driver. We are not exposing it in flang-new.

Ok good then.

clang/include/clang/Driver/Options.td

 def fdebug_unparse_with_symbols : Flag<["-"], "fdebug-unparse-with-symbols">, Group<Action_Group>,
   HelpText<"Unparse and stop.">;
 def fdebug_dump_symbols : Flag<["-"], "fdebug-dump-symbols">, Group<Action_Group>,
   HelpText<"Dump symbols after the semantic analysis">;
 def fdebug_dump_parse_tree : Flag<["-"], "fdebug-dump-parse-tree">, Group<Action_Group>,
   HelpText<"Dump the parse tree">,
   DocBrief<[{Run the Parser and the semantic checks, and then output the
 parse tree.}]>;
+def fdebug_dump_pft : Flag<["-"], "fdebug-dump-pft">, Group<Action_Group>,
+  HelpText<"Dump the pre-fir parse tree">;
 def fdebug_dump_parse_tree_no_sema : Flag<["-"], "fdebug-dump-parse-tree-no-sema">, Group<Action_Group>,
   HelpText<"Dump the parse tree (skips the semantic checks)">,
   DocBrief<[{Run the Parser and then output the parse tree. Semantic
 checks are disabled.}]>;
 def fdebug_dump_all : Flag<["-"], "fdebug-dump-all">, Group<Action_Group>,
   HelpText<"Dump symbols and the parse tree after the semantic checks">;
 def fdebug_dump_provenance : Flag<["-"], "fdebug-dump-provenance">, Group<Action_Group>,
   HelpText<"Dump provenance">;

flang/include/flang/Frontend/FrontendActions.h

 class DebugDumpSymbolsAction : public PrescanAndSemaAction {
   void ExecuteAction() override;
 };
 
 class DebugDumpParseTreeAction : public PrescanAndSemaAction {
   void ExecuteAction() override;
 };
 
+class DebugDumpPFTAction : public PrescanAndSemaAction {
+  void ExecuteAction() override;
+};
+
 class DebugPreFIRTreeAction : public PrescanAndSemaAction {
   void ExecuteAction() override;
 };
 
 class GetDefinitionAction : public PrescanAndSemaAction {
   void ExecuteAction() override;
 };
 

flang/include/flang/Frontend/FrontendOptions.h

enum ActionKind {
   DebugUnparseWithSymbols,
 
   /// Parse, run semantics and then output symbols from semantics
   DebugDumpSymbols,
 
   /// Parse, run semantics and then output the parse tree
   DebugDumpParseTree,
 
+  /// Parse, run semantics and then output the pre-fir parse tree
+  DebugDumpPFT,
+
   /// Parse, run semantics and then output the parse tree and symbols
   DebugDumpAll,
 
   /// Parse and then output the parse tree, skip the semantic checks
   DebugDumpParseTreeNoSema,
 
   /// Dump provenance
   DebugDumpProvenance,

flang/lib/Frontend/CompilerInvocation.cpp

case clang::driver::options::OPT_fdebug_unparse_with_symbols:
       opts.programAction = DebugUnparseWithSymbols;
       break;
     case clang::driver::options::OPT_fdebug_dump_symbols:
       opts.programAction = DebugDumpSymbols;
       break;
     case clang::driver::options::OPT_fdebug_dump_parse_tree:
       opts.programAction = DebugDumpParseTree;
       break;
+    case clang::driver::options::OPT_fdebug_dump_pft:
+      opts.programAction = DebugDumpPFT;
+      break;
     case clang::driver::options::OPT_fdebug_dump_all:
       opts.programAction = DebugDumpAll;
       break;
     case clang::driver::options::OPT_fdebug_dump_parse_tree_no_sema:
       opts.programAction = DebugDumpParseTreeNoSema;
       break;
     case clang::driver::options::OPT_fdebug_dump_provenance:
       opts.programAction = DebugDumpProvenance;

flang/lib/Frontend/FrontendActions.cpp

void InitOnlyAction::ExecuteAction() {
   CompilerInstance &ci = this->instance();
   unsigned DiagID =
       ci.diagnostics().getCustomDiagID(clang::DiagnosticsEngine::Warning,
           "Use `-init-only` for testing purposes only");
   ci.diagnostics().Report(DiagID);
 }
 
 void PluginParseTreeAction::ExecuteAction() {}
+
+void DebugDumpPFTAction::ExecuteAction() {
+  CompilerInstance &ci = this->instance();
+
+  if (auto ast = Fortran::lower::createPFT(
+          *ci.parsing().parseTree(), ci.semantics().context())) {
+    Fortran::lower::dumpPFT(llvm::outs(), *ast);
+    return;
+  }
+
+  unsigned DiagID = ci.diagnostics().getCustomDiagID(
+      clang::DiagnosticsEngine::Error, "Pre FIR Tree is NULL.");
+  ci.diagnostics().Report(DiagID);
+}

flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp

static std::unique_ptr<FrontendAction> CreateFrontendBaseAction(
   case DebugUnparseNoSema:
     return std::make_unique<DebugUnparseNoSemaAction>();
   case DebugUnparseWithSymbols:
     return std::make_unique<DebugUnparseWithSymbolsAction>();
   case DebugDumpSymbols:
     return std::make_unique<DebugDumpSymbolsAction>();
   case DebugDumpParseTree:
     return std::make_unique<DebugDumpParseTreeAction>();
+  case DebugDumpPFT:
+    return std::make_unique<DebugDumpPFTAction>();
   case DebugDumpParseTreeNoSema:
     return std::make_unique<DebugDumpParseTreeNoSemaAction>();
   case DebugDumpAll:
     return std::make_unique<DebugDumpAllAction>();
   case DebugDumpProvenance:
     return std::make_unique<DebugDumpProvenanceAction>();
   case DebugDumpParsingLog:
     return std::make_unique<DebugDumpParsingLogAction>();

flang/test/Driver/driver-help.f90

 ! HELP-FC1-NEXT: Enable the old style PARAMETER statement
 ! HELP-FC1-NEXT: -fbackslash            Specify that backslash in string introduces an escape character
 ! HELP-FC1-NEXT: -fdebug-dump-all       Dump symbols and the parse tree after the semantic checks
 ! HELP-FC1-NEXT: -fdebug-dump-parse-tree-no-sema
 ! HELP-FC1-NEXT:                        Dump the parse tree (skips the semantic checks)
 ! HELP-FC1-NEXT: -fdebug-dump-parse-tree Dump the parse tree
 ! HELP-FC1-NEXT: -fdebug-dump-parsing-log
 ! HELP-FC1-NEXT:                   Run instrumented parse and dump the parsing log
+! HELP-FC1-NEXT: -fdebug-dump-pft        Dump the pre-fir parse tree
 ! HELP-FC1-NEXT: -fdebug-dump-provenance Dump provenance
 ! HELP-FC1-NEXT: -fdebug-dump-symbols    Dump symbols after the semantic analysis
 ! HELP-FC1-NEXT: -fdebug-measure-parse-tree
 ! HELP-FC1-NEXT:                         Measure the parse tree
 ! HELP-FC1-NEXT: -fdebug-module-writer   Enable debug messages while writing module files
 ! HELP-FC1-NEXT: -fdebug-pre-fir-tree    Dump the pre-FIR tree
 ! HELP-FC1-NEXT: -fdebug-unparse-no-sema Unparse and stop (skips the semantic checks)
 ! HELP-FC1-NEXT: -fdebug-unparse-with-symbols

flang/test/Driver/dump-pft.f90

+!-------------
+! RUN COMMANDS
+!-------------
+! RUN: %flang_fc1 -fdebug-dump-parse-tree %s 2>&1 | FileCheck %s --check-prefix=PARSE_TREE
+! RUN: %flang_fc1 -fdebug-dump-pft %s 2>&1 | FileCheck %s --check-prefix=PFT
+! RUN: bbc -pft-test %s 2>&1 | FileCheck %s --check-prefix=PFT
+
+!-----------------
+! EXPECTEED OUTPUT
+!-----------------
+! PFT: 1 Subroutine test_routine: subroutine test_routine(a, b, n)
+! PFT-NEXT:  1 EndSubroutineStmt: end subroutine
+! PRF-NEXT: End Subroutine test_routine
+! PFT-NO: Program -> ProgramUnit -> SubroutineSubprogram
+
+! PARSE_TREE: Program -> ProgramUnit -> SubroutineSubprogram
+! PARSE_TREE-NEXT: | SubroutineStmt
+! PARSE_TREE-NEXT: | | Name = 'test_routine'
+! PARSE_TREE-NEXT: | | DummyArg -> Name = 'a'
+! PARSE_TREE-NEXT: | | DummyArg -> Name = 'b'
+! PARSE_TREE-NEXT: | | DummyArg -> Name = 'n'
+! PARSE_TREE-NEXT: | SpecificationPart
+! PARSE_TREE-NEXT: | | ImplicitPart ->
+! PARSE_TREE-NEXT: | ExecutionPart -> Block
+! PARSE_TREE-NEXT: | EndSubroutineStmt ->
+! PARSE_TREE-NO: Subroutine test_routine: subroutine test_routine(a, b, n)
+
+!-------
+! INPUT
+!-------
+subroutine test_routine(a, b, n)
+end subroutine