xref: /llvm-project/flang/tools/flang-driver/fc1_main.cpp (revision 23d7a6cedb5198535086a67586487f19effbd411)
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 
33 using namespace Fortran::frontend;
34 
35 /// Print supported cpus of the given target.
36 static int printSupportedCPUs(llvm::StringRef triple) {
37   std::string error;
38   const llvm::Target *target =
39       llvm::TargetRegistry::lookupTarget(triple, 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(triple, "", "+cpuhelp", targetOpts,
49                                   std::nullopt));
50   return 0;
51 }
52 
53 int 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   llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> diagOpts =
71       new clang::DiagnosticOptions();
72   clang::DiagnosticsEngine diags(diagID, &*diagOpts, diagsBuffer);
73   bool success = CompilerInvocation::createFromArgs(flang->getInvocation(),
74                                                     argv, diags, argv0);
75 
76   // Initialize targets first, so that --version shows registered targets.
77   llvm::InitializeAllTargets();
78   llvm::InitializeAllTargetMCs();
79   llvm::InitializeAllAsmPrinters();
80 
81   // --print-supported-cpus takes priority over the actual compilation.
82   if (flang->getFrontendOpts().printSupportedCPUs)
83     return printSupportedCPUs(flang->getInvocation().getTargetOpts().triple);
84 
85   diagsBuffer->flushDiagnostics(flang->getDiagnostics());
86 
87   if (!success)
88     return 1;
89 
90   // Execute the frontend actions.
91   success = executeCompilerInvocation(flang.get());
92 
93   // Delete output files to free Compiler Instance
94   flang->clearOutputFiles(/*EraseFiles=*/false);
95 
96   return !success;
97 }
98