1 //===-- lib/Semantics/program-tree.h ----------------------------*- C++ -*-===//
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 #ifndef FORTRAN_SEMANTICS_PROGRAM_TREE_H_
10 #define FORTRAN_SEMANTICS_PROGRAM_TREE_H_
11 
12 #include "flang/Parser/parse-tree.h"
13 #include "flang/Semantics/symbol.h"
14 #include <list>
15 #include <variant>
16 
17 // A ProgramTree represents a tree of program units and their contained
18 // subprograms. The root nodes represent: main program, function, subroutine,
19 // module subprogram, module, or submodule.
20 // Each node of the tree consists of:
21 //   - the statement that introduces the program unit
22 //   - the specification part
23 //   - the execution part if applicable (not for module or submodule)
24 //   - a child node for each contained subprogram
25 
26 namespace Fortran::semantics {
27 
28 class Scope;
29 
30 class ProgramTree {
31 public:
32   using EntryStmtList = std::list<common::Reference<const parser::EntryStmt>>;
33 
34   // Build the ProgramTree rooted at one of these program units.
35   static ProgramTree Build(const parser::ProgramUnit &);
36   static ProgramTree Build(const parser::MainProgram &);
37   static ProgramTree Build(const parser::FunctionSubprogram &);
38   static ProgramTree Build(const parser::SubroutineSubprogram &);
39   static ProgramTree Build(const parser::SeparateModuleSubprogram &);
40   static ProgramTree Build(const parser::Module &);
41   static ProgramTree Build(const parser::Submodule &);
42   static ProgramTree Build(const parser::BlockData &);
43   static ProgramTree Build(const parser::CompilerDirective &);
44 
45   ENUM_CLASS(Kind, // kind of node
46       Program, Function, Subroutine, MpSubprogram, Module, Submodule, BlockData)
47   using Stmt = std::variant< // the statement that introduces the program unit
48       const parser::Statement<parser::ProgramStmt> *,
49       const parser::Statement<parser::FunctionStmt> *,
50       const parser::Statement<parser::SubroutineStmt> *,
51       const parser::Statement<parser::MpSubprogramStmt> *,
52       const parser::Statement<parser::ModuleStmt> *,
53       const parser::Statement<parser::SubmoduleStmt> *,
54       const parser::Statement<parser::BlockDataStmt> *>;
55 
56   ProgramTree(const parser::Name &name, const parser::SpecificationPart &spec,
57       const parser::ExecutionPart *exec = nullptr)
58       : name_{name}, spec_{spec}, exec_{exec} {}
59 
60   const parser::Name &name() const { return name_; }
61   Kind GetKind() const;
62   const Stmt &stmt() const { return stmt_; }
63   bool isSpecificationPartResolved() const {
64     return isSpecificationPartResolved_;
65   }
66   void set_isSpecificationPartResolved(bool yes = true) {
67     isSpecificationPartResolved_ = yes;
68   }
69   const parser::ParentIdentifier &GetParentId() const; // only for Submodule
70   const parser::SpecificationPart &spec() const { return spec_; }
71   const parser::ExecutionPart *exec() const { return exec_; }
72   std::list<ProgramTree> &children() { return children_; }
73   const std::list<ProgramTree> &children() const { return children_; }
74   const std::list<common::Reference<const parser::EntryStmt>> &
75   entryStmts() const {
76     return entryStmts_;
77   }
78   Symbol::Flag GetSubpFlag() const;
79   bool IsModule() const; // Module or Submodule
80   bool HasModulePrefix() const; // in function or subroutine stmt
81   Scope *scope() const { return scope_; }
82   void set_scope(Scope &);
83   void AddChild(ProgramTree &&);
84   void AddEntry(const parser::EntryStmt &);
85 
86   template <typename T>
87   ProgramTree &set_stmt(const parser::Statement<T> &stmt) {
88     stmt_ = &stmt;
89     return *this;
90   }
91   template <typename T>
92   ProgramTree &set_endStmt(const parser::Statement<T> &stmt) {
93     endStmt_ = &stmt.source;
94     return *this;
95   }
96 
97 private:
98   const parser::Name &name_;
99   Stmt stmt_{
100       static_cast<const parser::Statement<parser::ProgramStmt> *>(nullptr)};
101   const parser::SpecificationPart &spec_;
102   const parser::ExecutionPart *exec_{nullptr};
103   std::list<ProgramTree> children_;
104   EntryStmtList entryStmts_;
105   Scope *scope_{nullptr};
106   const parser::CharBlock *endStmt_{nullptr};
107   bool isSpecificationPartResolved_{false};
108 };
109 
110 } // namespace Fortran::semantics
111 #endif // FORTRAN_SEMANTICS_PROGRAM_TREE_H_
112