flang/examples/PrintFlangFunctionNames/PrintFlangFunctionNames.cpp

   1 //===-- PrintFlangFunctionNames.cpp ---------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Small example Flang plugin to count/print Functions & Subroutines names.
  10 // It walks the Parse Tree using a Visitor struct that has Post functions for
  11 // FunctionStmt and SubroutineStmt to access the names of functions &
  12 // subroutines. It also has Pre functions for FunctionSubprogram and
  13 // SubroutineSubprogram so a Bool can be set to show that it is the definition
  14 // of a function/subroutine, and not print those that are in an Interface.
  15 // This plugin does not recognise Statement Functions or Module Procedures,
  16 // which could be dealt with through StmtFunctionStmt and MpSubprogramStmt nodes
  17 // respectively.
  18 //
  19 //===----------------------------------------------------------------------===//
  20
  21 #include "flang/Frontend/FrontendActions.h"
  22 #include "flang/Frontend/FrontendPluginRegistry.h"
  23 #include "flang/Parser/dump-parse-tree.h"
  24 #include "flang/Parser/parsing.h"
  25
  26 using namespace Fortran::frontend;
  27
  28 class PrintFunctionNamesAction : public PluginParseTreeAction {
  29
  30   // Visitor struct that defines Pre/Post functions for different types of nodes
  31   struct ParseTreeVisitor {
  32     template <typename A> bool Pre(const A &) { return true; }
  33     template <typename A> void Post(const A &) {}
  34
  35     bool Pre(const Fortran::parser::FunctionSubprogram &) {
  36       isInSubprogram_ = true;
  37       return true;
  38     }
  39     void Post(const Fortran::parser::FunctionStmt &f) {
  40       if (isInSubprogram_) {
  41         llvm::outs() << "Function:\t"
  42                      << std::get<Fortran::parser::Name>(f.t).ToString() << "\n";
  43         fcounter++;
  44         isInSubprogram_ = false;
  45       }
  46     }
  47
  48     bool Pre(const Fortran::parser::SubroutineSubprogram &) {
  49       isInSubprogram_ = true;
  50       return true;
  51     }
  52     void Post(const Fortran::parser::SubroutineStmt &s) {
  53       if (isInSubprogram_) {
  54         llvm::outs() << "Subroutine:\t"
  55                      << std::get<Fortran::parser::Name>(s.t).ToString() << "\n";
  56         scounter++;
  57         isInSubprogram_ = false;
  58       }
  59     }
  60
  61     int fcounter{0};
  62     int scounter{0};
  63
  64   private:
  65     bool isInSubprogram_{false};
  66   };
  67
  68   void executeAction() override {
  69     ParseTreeVisitor visitor;
  70     Fortran::parser::Walk(getParsing().parseTree(), visitor);
  71
  72     llvm::outs() << "\n====   Functions: " << visitor.fcounter << " ====\n";
  73     llvm::outs() << "==== Subroutines: " << visitor.scounter << " ====\n";
  74   }
  75 };
  76
  77 static FrontendPluginRegistry::Add<PrintFunctionNamesAction> X(
  78     "print-fns", "Print Function names");