xref: /llvm-project/flang/examples/PrintFlangFunctionNames/PrintFlangFunctionNames.cpp (revision ea18987094eff5a5835135da1f472d2e7bf6c68e)
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 {
PrePrintFunctionNamesAction::ParseTreeVisitor32     template <typename A> bool Pre(const A &) { return true; }
PostPrintFunctionNamesAction::ParseTreeVisitor33     template <typename A> void Post(const A &) {}
34 
PrePrintFunctionNamesAction::ParseTreeVisitor35     bool Pre(const Fortran::parser::FunctionSubprogram &) {
36       isInSubprogram_ = true;
37       return true;
38     }
PostPrintFunctionNamesAction::ParseTreeVisitor39     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 
PrePrintFunctionNamesAction::ParseTreeVisitor48     bool Pre(const Fortran::parser::SubroutineSubprogram &) {
49       isInSubprogram_ = true;
50       return true;
51     }
PostPrintFunctionNamesAction::ParseTreeVisitor52     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 
executeAction()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");
79