1//===-- driver.cpp - Flang Driver -----------------------------------------===//
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 driver; it is a thin wrapper
10// for functionality in the Driver flang library.
11//
12//===----------------------------------------------------------------------===//
13//
14// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
15//
16//===----------------------------------------------------------------------===//
17
18#include "clang/Driver/Driver.h"
19#include "flang/Frontend/CompilerInvocation.h"
20#include "flang/Frontend/TextDiagnosticPrinter.h"
21#include "clang/Basic/Diagnostic.h"
22#include "clang/Basic/DiagnosticIDs.h"
23#include "clang/Basic/DiagnosticOptions.h"
24#include "clang/Driver/Compilation.h"
25#include "llvm/ADT/ArrayRef.h"
26#include "llvm/ADT/IntrusiveRefCntPtr.h"
27#include "llvm/Option/ArgList.h"
28#include "llvm/Support/CommandLine.h"
29#include "llvm/Support/InitLLVM.h"
30#include "llvm/Support/VirtualFileSystem.h"
31#include "llvm/Support/raw_ostream.h"
32#include "llvm/TargetParser/Host.h"
33#include <stdlib.h>
34
35// main frontend method. Lives inside fc1_main.cpp
36extern int fc1_main(llvm::ArrayRef<const char *> argv, const char *argv0);
37
38std::string getExecutablePath(const char *argv0) {
39 // This just needs to be some symbol in the binary
40 void *p = (void *)(intptr_t)getExecutablePath;
41 return llvm::sys::fs::getMainExecutable(argv0, MainExecAddr: p);
42}
43
44// This lets us create the DiagnosticsEngine with a properly-filled-out
45// DiagnosticOptions instance
46static clang::DiagnosticOptions *
47createAndPopulateDiagOpts(llvm::ArrayRef<const char *> argv) {
48 auto *diagOpts = new clang::DiagnosticOptions;
49
50 // Ignore missingArgCount and the return value of ParseDiagnosticArgs.
51 // Any errors that would be diagnosed here will also be diagnosed later,
52 // when the DiagnosticsEngine actually exists.
53 unsigned missingArgIndex, missingArgCount;
54 llvm::opt::InputArgList args = clang::driver::getDriverOptTable().ParseArgs(
55 Args: argv.slice(N: 1), MissingArgIndex&: missingArgIndex, MissingArgCount&: missingArgCount,
56 VisibilityMask: llvm::opt::Visibility(clang::driver::options::FlangOption));
57
58 (void)Fortran::frontend::parseDiagnosticArgs(*diagOpts, args);
59
60 return diagOpts;
61}
62
63static int executeFC1Tool(llvm::SmallVectorImpl<const char *> &argV) {
64 llvm::StringRef tool = argV[1];
65 if (tool == "-fc1")
66 return fc1_main(argv: llvm::ArrayRef(argV).slice(N: 2), argv0: argV[0]);
67
68 // Reject unknown tools.
69 // ATM it only supports fc1. Any fc1[*] is rejected.
70 llvm::errs() << "error: unknown integrated tool '" << tool << "'. "
71 << "Valid tools include '-fc1'.\n";
72 return 1;
73}
74
75static void ExpandResponseFiles(llvm::StringSaver &saver,
76 llvm::SmallVectorImpl<const char *> &args) {
77 // We're defaulting to the GNU syntax, since we don't have a CL mode.
78 llvm::cl::TokenizerCallback tokenizer = &llvm::cl::TokenizeGNUCommandLine;
79 llvm::cl::ExpansionContext ExpCtx(saver.getAllocator(), tokenizer);
80 if (llvm::Error Err = ExpCtx.expandResponseFiles(Argv&: args)) {
81 llvm::errs() << toString(E: std::move(Err)) << '\n';
82 }
83}
84
85int main(int argc, const char **argv) {
86
87 // Initialize variables to call the driver
88 llvm::InitLLVM x(argc, argv);
89 llvm::SmallVector<const char *, 256> args(argv, argv + argc);
90
91 clang::driver::ParsedClangName targetandMode("flang", "--driver-mode=flang");
92 std::string driverPath = getExecutablePath(argv0: args[0]);
93
94 llvm::BumpPtrAllocator a;
95 llvm::StringSaver saver(a);
96 ExpandResponseFiles(saver, args);
97
98 // Check if flang-new is in the frontend mode
99 auto firstArg = std::find_if(first: args.begin() + 1, last: args.end(),
100 pred: [](const char *a) { return a != nullptr; });
101 if (firstArg != args.end()) {
102 if (llvm::StringRef(args[1]).starts_with(Prefix: "-cc1")) {
103 llvm::errs() << "error: unknown integrated tool '" << args[1] << "'. "
104 << "Valid tools include '-fc1'.\n";
105 return 1;
106 }
107 // Call flang-new frontend
108 if (llvm::StringRef(args[1]).starts_with(Prefix: "-fc1")) {
109 return executeFC1Tool(argV&: args);
110 }
111 }
112
113 // Not in the frontend mode - continue in the compiler driver mode.
114
115 // Create DiagnosticsEngine for the compiler driver
116 llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> diagOpts =
117 createAndPopulateDiagOpts(argv: args);
118 llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagID(
119 new clang::DiagnosticIDs());
120 Fortran::frontend::TextDiagnosticPrinter *diagClient =
121 new Fortran::frontend::TextDiagnosticPrinter(llvm::errs(), &*diagOpts);
122
123 diagClient->setPrefix(
124 std::string(llvm::sys::path::stem(path: getExecutablePath(argv0: args[0]))));
125
126 clang::DiagnosticsEngine diags(diagID, &*diagOpts, diagClient);
127
128 // Prepare the driver
129 clang::driver::Driver theDriver(driverPath,
130 llvm::sys::getDefaultTargetTriple(), diags,
131 "flang LLVM compiler");
132 theDriver.setTargetAndMode(targetandMode);
133#ifdef FLANG_RUNTIME_F128_MATH_LIB
134 theDriver.setFlangF128MathLibrary(FLANG_RUNTIME_F128_MATH_LIB);
135#endif
136 std::unique_ptr<clang::driver::Compilation> c(
137 theDriver.BuildCompilation(Args: args));
138 llvm::SmallVector<std::pair<int, const clang::driver::Command *>, 4>
139 failingCommands;
140
141 // Set the environment variable, FLANG_COMPILER_OPTIONS_STRING, to contain all
142 // the compiler options. This is intended for the frontend driver,
143 // flang-new -fc1, to enable the implementation of the COMPILER_OPTIONS
144 // intrinsic. To this end, the frontend driver requires the list of the
145 // original compiler options, which is not available through other means.
146 // TODO: This way of passing information between the compiler and frontend
147 // drivers is discouraged. We should find a better way not involving env
148 // variables.
149 std::string compilerOptsGathered;
150 llvm::raw_string_ostream os(compilerOptsGathered);
151 for (int i = 0; i < argc; ++i) {
152 os << argv[i];
153 if (i < argc - 1) {
154 os << ' ';
155 }
156 }
157#ifdef _WIN32
158 _putenv_s("FLANG_COMPILER_OPTIONS_STRING", compilerOptsGathered.c_str());
159#else
160 setenv(name: "FLANG_COMPILER_OPTIONS_STRING", value: compilerOptsGathered.c_str(), replace: 1);
161#endif
162
163 // Run the driver
164 int res = 1;
165 bool isCrash = false;
166 res = theDriver.ExecuteCompilation(C&: *c, FailingCommands&: failingCommands);
167
168 for (const auto &p : failingCommands) {
169 int commandRes = p.first;
170 const clang::driver::Command *failingCommand = p.second;
171 if (!res)
172 res = commandRes;
173
174 // If result status is < 0 (e.g. when sys::ExecuteAndWait returns -1),
175 // then the driver command signalled an error. On Windows, abort will
176 // return an exit code of 3. In these cases, generate additional diagnostic
177 // information if possible.
178 isCrash = commandRes < 0;
179#ifdef _WIN32
180 isCrash |= commandRes == 3;
181#endif
182 if (isCrash) {
183 theDriver.generateCompilationDiagnostics(C&: *c, FailingCommand: *failingCommand);
184 break;
185 }
186 }
187
188 diags.getClient()->finish();
189
190 // If we have multiple failing commands, we return the result of the first
191 // failing command.
192 return res;
193}
194

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