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 std::unique_ptr<clang::DiagnosticOptions>
47createAndPopulateDiagOpts(llvm::ArrayRef<const char *> argv) {
48 auto diagOpts = std::make_unique<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 =
92 clang::driver::ToolChain::getTargetAndModeFromProgramName(ProgName: argv[0]);
93 std::string driverPath = getExecutablePath(argv0: args[0]);
94
95 llvm::BumpPtrAllocator a;
96 llvm::StringSaver saver(a);
97 ExpandResponseFiles(saver, args);
98
99 // Check if flang is in the frontend mode
100 auto firstArg = std::find_if(first: args.begin() + 1, last: args.end(),
101 pred: [](const char *a) { return a != nullptr; });
102 if (firstArg != args.end()) {
103 if (llvm::StringRef(args[1]).starts_with(Prefix: "-cc1")) {
104 llvm::errs() << "error: unknown integrated tool '" << args[1] << "'. "
105 << "Valid tools include '-fc1'.\n";
106 return 1;
107 }
108 // Call flang frontend
109 if (llvm::StringRef(args[1]).starts_with(Prefix: "-fc1")) {
110 return executeFC1Tool(argV&: args);
111 }
112 }
113
114 llvm::StringSet<> savedStrings;
115 // Handle FCC_OVERRIDE_OPTIONS, used for editing a command line behind the
116 // scenes.
117 if (const char *overrideStr = ::getenv(name: "FCC_OVERRIDE_OPTIONS"))
118 clang::driver::applyOverrideOptions(Args&: args, OverrideOpts: overrideStr, SavedStrings&: savedStrings,
119 EnvVar: "FCC_OVERRIDE_OPTIONS", OS: &llvm::errs());
120
121 // Not in the frontend mode - continue in the compiler driver mode.
122
123 // Create DiagnosticsEngine for the compiler driver
124 std::unique_ptr<clang::DiagnosticOptions> diagOpts =
125 createAndPopulateDiagOpts(argv: args);
126 llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagID(
127 new clang::DiagnosticIDs());
128 Fortran::frontend::TextDiagnosticPrinter *diagClient =
129 new Fortran::frontend::TextDiagnosticPrinter(llvm::errs(), *diagOpts);
130
131 diagClient->setPrefix(
132 std::string(llvm::sys::path::stem(path: getExecutablePath(argv0: args[0]))));
133
134 clang::DiagnosticsEngine diags(diagID, *diagOpts, diagClient);
135
136 // Prepare the driver
137 clang::driver::Driver theDriver(driverPath,
138 llvm::sys::getDefaultTargetTriple(), diags,
139 "flang LLVM compiler");
140 theDriver.setTargetAndMode(targetandMode);
141#ifdef FLANG_RUNTIME_F128_MATH_LIB
142 theDriver.setFlangF128MathLibrary(FLANG_RUNTIME_F128_MATH_LIB);
143#endif
144 std::unique_ptr<clang::driver::Compilation> c(
145 theDriver.BuildCompilation(Args: args));
146 llvm::SmallVector<std::pair<int, const clang::driver::Command *>, 4>
147 failingCommands;
148
149 // Set the environment variable, FLANG_COMPILER_OPTIONS_STRING, to contain all
150 // the compiler options. This is intended for the frontend driver,
151 // flang -fc1, to enable the implementation of the COMPILER_OPTIONS
152 // intrinsic. To this end, the frontend driver requires the list of the
153 // original compiler options, which is not available through other means.
154 // TODO: This way of passing information between the compiler and frontend
155 // drivers is discouraged. We should find a better way not involving env
156 // variables.
157 std::string compilerOptsGathered;
158 llvm::raw_string_ostream os(compilerOptsGathered);
159 for (int i = 0; i < argc; ++i) {
160 os << argv[i];
161 if (i < argc - 1) {
162 os << ' ';
163 }
164 }
165#ifdef _WIN32
166 _putenv_s("FLANG_COMPILER_OPTIONS_STRING", compilerOptsGathered.c_str());
167#else
168 setenv(name: "FLANG_COMPILER_OPTIONS_STRING", value: compilerOptsGathered.c_str(), replace: 1);
169#endif
170
171 // Run the driver
172 int res = 1;
173 bool isCrash = false;
174 res = theDriver.ExecuteCompilation(C&: *c, FailingCommands&: failingCommands);
175
176 for (const auto &p : failingCommands) {
177 int commandRes = p.first;
178 const clang::driver::Command *failingCommand = p.second;
179 if (!res)
180 res = commandRes;
181
182 // If result status is < 0 (e.g. when sys::ExecuteAndWait returns -1),
183 // then the driver command signalled an error. On Windows, abort will
184 // return an exit code of 3. In these cases, generate additional diagnostic
185 // information if possible.
186 isCrash = commandRes < 0;
187#ifdef _WIN32
188 isCrash |= commandRes == 3;
189#endif
190 if (isCrash) {
191 theDriver.generateCompilationDiagnostics(C&: *c, FailingCommand: *failingCommand);
192 break;
193 }
194 }
195
196 diags.getClient()->finish();
197
198 // If we have multiple failing commands, we return the result of the first
199 // failing command.
200 return res;
201}
202

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