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