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
26using namespace Fortran::frontend;
27
28class 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
77static FrontendPluginRegistry::Add<PrintFunctionNamesAction> X(
78 "print-fns", "Print Function names");
79

source code of flang/examples/PrintFlangFunctionNames/PrintFlangFunctionNames.cpp