1 //===-- lib/Semantics/check-return.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 #include "check-return.h" 10 #include "flang/Common/Fortran-features.h" 11 #include "flang/Parser/message.h" 12 #include "flang/Parser/parse-tree.h" 13 #include "flang/Semantics/semantics.h" 14 #include "flang/Semantics/tools.h" 15 16 namespace Fortran::semantics { 17 18 static const Scope *FindContainingSubprogram(const Scope &start) { 19 const Scope &scope{GetProgramUnitContaining(start)}; 20 return scope.kind() == Scope::Kind::MainProgram || 21 scope.kind() == Scope::Kind::Subprogram 22 ? &scope 23 : nullptr; 24 } 25 26 void ReturnStmtChecker::Leave(const parser::ReturnStmt &returnStmt) { 27 // R1542 Expression analysis validates the scalar-int-expr 28 // C1574 The return-stmt shall be in the inclusive scope of a function or 29 // subroutine subprogram. 30 // C1575 The scalar-int-expr is allowed only in the inclusive scope of a 31 // subroutine subprogram. 32 const auto &scope{context_.FindScope(context_.location().value())}; 33 if (const auto *subprogramScope{FindContainingSubprogram(scope)}) { 34 if (returnStmt.v && 35 (subprogramScope->kind() == Scope::Kind::MainProgram || 36 IsFunction(*subprogramScope->GetSymbol()))) { 37 context_.Say( 38 "RETURN with expression is only allowed in SUBROUTINE subprogram"_err_en_US); 39 } else if (subprogramScope->kind() == Scope::Kind::MainProgram) { 40 context_.Warn(common::LanguageFeature::ProgramReturn, 41 "RETURN should not appear in a main program"_port_en_US); 42 } 43 } 44 } 45 46 } // namespace Fortran::semantics 47