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   // Build the ProgramTree rooted at one of these program units.
33   static ProgramTree Build(const parser::ProgramUnit &);
34   static ProgramTree Build(const parser::MainProgram &);
35   static ProgramTree Build(const parser::FunctionSubprogram &);
36   static ProgramTree Build(const parser::SubroutineSubprogram &);
37   static ProgramTree Build(const parser::SeparateModuleSubprogram &);
38   static ProgramTree Build(const parser::Module &);
39   static ProgramTree Build(const parser::Submodule &);
40   static ProgramTree Build(const parser::BlockData &);
41   static ProgramTree Build(const parser::CompilerDirective &);
42 
43   ENUM_CLASS(Kind, // kind of node
44       Program, Function, Subroutine, MpSubprogram, Module, Submodule, BlockData)
45   using Stmt = std::variant< // the statement that introduces the program unit
46       const parser::Statement<parser::ProgramStmt> *,
47       const parser::Statement<parser::FunctionStmt> *,
48       const parser::Statement<parser::SubroutineStmt> *,
49       const parser::Statement<parser::MpSubprogramStmt> *,
50       const parser::Statement<parser::ModuleStmt> *,
51       const parser::Statement<parser::SubmoduleStmt> *,
52       const parser::Statement<parser::BlockDataStmt> *>;
53 
54   ProgramTree(const parser::Name &name, const parser::SpecificationPart &spec,
55       const parser::ExecutionPart *exec = nullptr)
56       : name_{name}, spec_{spec}, exec_{exec} {}
57 
name()58   const parser::Name &name() const { return name_; }
59   Kind GetKind() const;
stmt()60   const Stmt &stmt() const { return stmt_; }
isSpecificationPartResolved()61   bool isSpecificationPartResolved() const {
62     return isSpecificationPartResolved_;
63   }
64   void set_isSpecificationPartResolved(bool yes = true) {
65     isSpecificationPartResolved_ = yes;
66   }
67   const parser::ParentIdentifier &GetParentId() const; // only for Submodule
spec()68   const parser::SpecificationPart &spec() const { return spec_; }
exec()69   const parser::ExecutionPart *exec() const { return exec_; }
children()70   std::list<ProgramTree> &children() { return children_; }
children()71   const std::list<ProgramTree> &children() const { return children_; }
72   Symbol::Flag GetSubpFlag() const;
73   bool IsModule() const; // Module or Submodule
74   bool HasModulePrefix() const; // in function or subroutine stmt
scope()75   Scope *scope() const { return scope_; }
76   void set_scope(Scope &);
77   void AddChild(ProgramTree &&);
78 
79   template <typename T>
set_stmt(const parser::Statement<T> & stmt)80   ProgramTree &set_stmt(const parser::Statement<T> &stmt) {
81     stmt_ = &stmt;
82     return *this;
83   }
84   template <typename T>
set_endStmt(const parser::Statement<T> & stmt)85   ProgramTree &set_endStmt(const parser::Statement<T> &stmt) {
86     endStmt_ = &stmt.source;
87     return *this;
88   }
89 
90 private:
91   const parser::Name &name_;
92   Stmt stmt_{
93       static_cast<const parser::Statement<parser::ProgramStmt> *>(nullptr)};
94   const parser::SpecificationPart &spec_;
95   const parser::ExecutionPart *exec_{nullptr};
96   std::list<ProgramTree> children_;
97   Scope *scope_{nullptr};
98   const parser::CharBlock *endStmt_{nullptr};
99   bool isSpecificationPartResolved_{false};
100 };
101 
102 } // namespace Fortran::semantics
103 #endif // FORTRAN_SEMANTICS_PROGRAM_TREE_H_
104