1//===-- fc1_main.cpp - Flang FC1 Compiler Frontend ------------------------===//
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// This is the entry point to the flang -fc1 functionality, which implements the
10// core compiler functionality along with a number of additional tools for
11// demonstration and testing purposes.
12//
13//===----------------------------------------------------------------------===//
14//
15// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
16//
17//===----------------------------------------------------------------------===//
18
19#include "flang/Frontend/CompilerInstance.h"
20#include "flang/Frontend/CompilerInvocation.h"
21#include "flang/Frontend/TextDiagnosticBuffer.h"
22#include "flang/FrontendTool/Utils.h"
23#include "clang/Driver/DriverDiagnostic.h"
24#include "llvm/MC/TargetRegistry.h"
25#include "llvm/Option/Arg.h"
26#include "llvm/Option/ArgList.h"
27#include "llvm/Option/OptTable.h"
28#include "llvm/Support/TargetSelect.h"
29#include "llvm/Support/raw_ostream.h"
30
31#include <cstdio>
32
33using namespace Fortran::frontend;
34
35/// Print supported cpus of the given target.
36static int printSupportedCPUs(llvm::StringRef triple) {
37 std::string error;
38 const llvm::Target *target =
39 llvm::TargetRegistry::lookupTarget(TripleStr: triple, Error&: error);
40 if (!target) {
41 llvm::errs() << error;
42 return 1;
43 }
44
45 // the target machine will handle the mcpu printing
46 llvm::TargetOptions targetOpts;
47 std::unique_ptr<llvm::TargetMachine> targetMachine(
48 target->createTargetMachine(llvm::Triple(triple), "", "+cpuhelp",
49 targetOpts, std::nullopt));
50 return 0;
51}
52
53int fc1_main(llvm::ArrayRef<const char *> argv, const char *argv0) {
54 // Create CompilerInstance
55 std::unique_ptr<CompilerInstance> flang(new CompilerInstance());
56
57 // Create DiagnosticsEngine for the frontend driver
58 flang->createDiagnostics();
59 if (!flang->hasDiagnostics())
60 return 1;
61
62 // We will buffer diagnostics from argument parsing so that we can output
63 // them using a well formed diagnostic object.
64 TextDiagnosticBuffer *diagsBuffer = new TextDiagnosticBuffer;
65
66 // Create CompilerInvocation - use a dedicated instance of DiagnosticsEngine
67 // for parsing the arguments
68 llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagID(
69 new clang::DiagnosticIDs());
70 clang::DiagnosticOptions diagOpts;
71 clang::DiagnosticsEngine diags(diagID, diagOpts, diagsBuffer);
72 bool success = CompilerInvocation::createFromArgs(flang->getInvocation(),
73 argv, diags, argv0);
74
75 // Initialize targets first, so that --version shows registered targets.
76 llvm::InitializeAllTargets();
77 llvm::InitializeAllTargetMCs();
78 llvm::InitializeAllAsmPrinters();
79
80 // --print-supported-cpus takes priority over the actual compilation.
81 if (flang->getFrontendOpts().printSupportedCPUs)
82 return printSupportedCPUs(flang->getInvocation().getTargetOpts().triple);
83
84 diagsBuffer->flushDiagnostics(flang->getDiagnostics());
85
86 if (!success)
87 return 1;
88
89 // Execute the frontend actions.
90 success = executeCompilerInvocation(flang.get());
91
92 // Delete output files to free Compiler Instance
93 flang->clearOutputFiles(/*EraseFiles=*/false);
94
95 return !success;
96}
97

source code of flang/tools/flang-driver/fc1_main.cpp