1 //===-- Runtime.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 "flang/Lower/Runtime.h"
10 #include "flang/Lower/Bridge.h"
11 #include "flang/Lower/StatementContext.h"
12 #include "flang/Lower/Todo.h"
13 #include "flang/Optimizer/Builder/FIRBuilder.h"
14 #include "flang/Optimizer/Builder/Runtime/RTBuilder.h"
15 #include "flang/Parser/parse-tree.h"
16 #include "flang/Runtime/pointer.h"
17 #include "flang/Runtime/stop.h"
18 #include "flang/Semantics/tools.h"
19 #include "llvm/Support/Debug.h"
20 
21 #define DEBUG_TYPE "flang-lower-runtime"
22 
23 using namespace Fortran::runtime;
24 
25 /// Runtime calls that do not return to the caller indicate this condition by
26 /// terminating the current basic block with an unreachable op.
27 static void genUnreachable(fir::FirOpBuilder &builder, mlir::Location loc) {
28   builder.create<fir::UnreachableOp>(loc);
29   mlir::Block *newBlock =
30       builder.getBlock()->splitBlock(builder.getInsertionPoint());
31   builder.setInsertionPointToStart(newBlock);
32 }
33 
34 //===----------------------------------------------------------------------===//
35 // Misc. Fortran statements that lower to runtime calls
36 //===----------------------------------------------------------------------===//
37 
38 void Fortran::lower::genStopStatement(
39     Fortran::lower::AbstractConverter &converter,
40     const Fortran::parser::StopStmt &stmt) {
41   fir::FirOpBuilder &builder = converter.getFirOpBuilder();
42   mlir::Location loc = converter.getCurrentLocation();
43   Fortran::lower::StatementContext stmtCtx;
44   llvm::SmallVector<mlir::Value> operands;
45   mlir::FuncOp callee;
46   mlir::FunctionType calleeType;
47   // First operand is stop code (zero if absent)
48   if (const auto &code =
49           std::get<std::optional<Fortran::parser::StopCode>>(stmt.t)) {
50     auto expr =
51         converter.genExprValue(*Fortran::semantics::GetExpr(*code), stmtCtx);
52     LLVM_DEBUG(llvm::dbgs() << "stop expression: "; expr.dump();
53                llvm::dbgs() << '\n');
54     expr.match(
55         [&](const fir::CharBoxValue &x) {
56           callee = fir::runtime::getRuntimeFunc<mkRTKey(StopStatementText)>(
57               loc, builder);
58           calleeType = callee.getType();
59           // Creates a pair of operands for the CHARACTER and its LEN.
60           operands.push_back(
61               builder.createConvert(loc, calleeType.getInput(0), x.getAddr()));
62           operands.push_back(
63               builder.createConvert(loc, calleeType.getInput(1), x.getLen()));
64         },
65         [&](fir::UnboxedValue x) {
66           callee = fir::runtime::getRuntimeFunc<mkRTKey(StopStatement)>(
67               loc, builder);
68           calleeType = callee.getType();
69           mlir::Value cast =
70               builder.createConvert(loc, calleeType.getInput(0), x);
71           operands.push_back(cast);
72         },
73         [&](auto) {
74           mlir::emitError(loc, "unhandled expression in STOP");
75           std::exit(1);
76         });
77   } else {
78     callee = fir::runtime::getRuntimeFunc<mkRTKey(StopStatement)>(loc, builder);
79     calleeType = callee.getType();
80     operands.push_back(
81         builder.createIntegerConstant(loc, calleeType.getInput(0), 0));
82   }
83 
84   // Second operand indicates ERROR STOP
85   bool isError = std::get<Fortran::parser::StopStmt::Kind>(stmt.t) ==
86                  Fortran::parser::StopStmt::Kind::ErrorStop;
87   operands.push_back(builder.createIntegerConstant(
88       loc, calleeType.getInput(operands.size()), isError));
89 
90   // Third operand indicates QUIET (default to false).
91   if (const auto &quiet =
92           std::get<std::optional<Fortran::parser::ScalarLogicalExpr>>(stmt.t)) {
93     const SomeExpr *expr = Fortran::semantics::GetExpr(*quiet);
94     assert(expr && "failed getting typed expression");
95     mlir::Value q = fir::getBase(converter.genExprValue(*expr, stmtCtx));
96     operands.push_back(
97         builder.createConvert(loc, calleeType.getInput(operands.size()), q));
98   } else {
99     operands.push_back(builder.createIntegerConstant(
100         loc, calleeType.getInput(operands.size()), 0));
101   }
102 
103   builder.create<fir::CallOp>(loc, callee, operands);
104   genUnreachable(builder, loc);
105 }
106 
107 void Fortran::lower::genPauseStatement(
108     Fortran::lower::AbstractConverter &converter,
109     const Fortran::parser::PauseStmt &) {
110   fir::FirOpBuilder &builder = converter.getFirOpBuilder();
111   mlir::Location loc = converter.getCurrentLocation();
112   mlir::FuncOp callee =
113       fir::runtime::getRuntimeFunc<mkRTKey(PauseStatement)>(loc, builder);
114   builder.create<fir::CallOp>(loc, callee, llvm::None);
115 }
116 
117 mlir::Value Fortran::lower::genAssociated(fir::FirOpBuilder &builder,
118                                           mlir::Location loc,
119                                           mlir::Value pointer,
120                                           mlir::Value target) {
121   mlir::FuncOp func =
122       fir::runtime::getRuntimeFunc<mkRTKey(PointerIsAssociatedWith)>(loc,
123                                                                      builder);
124   llvm::SmallVector<mlir::Value> args = fir::runtime::createArguments(
125       builder, loc, func.getType(), pointer, target);
126   return builder.create<fir::CallOp>(loc, func, args).getResult(0);
127 }
128