xref: /llvm-project/flang/tools/flang-driver/driver.cpp (revision 06eb10dadfaeaadc5d0d95d38bea4bfb5253e077)
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
36 extern int fc1_main(llvm::ArrayRef<const char *> argv, const char *argv0);
37 
38 std::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, p);
42 }
43 
44 // This lets us create the DiagnosticsEngine with a properly-filled-out
45 // DiagnosticOptions instance
46 static clang::DiagnosticOptions *
47 createAndPopulateDiagOpts(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       argv.slice(1), missingArgIndex, missingArgCount,
56       llvm::opt::Visibility(clang::driver::options::FlangOption));
57 
58   (void)Fortran::frontend::parseDiagnosticArgs(*diagOpts, args);
59 
60   return diagOpts;
61 }
62 
63 static int executeFC1Tool(llvm::SmallVectorImpl<const char *> &argV) {
64   llvm::StringRef tool = argV[1];
65   if (tool == "-fc1")
66     return fc1_main(llvm::ArrayRef(argV).slice(2), 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 
75 static 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(args)) {
81     llvm::errs() << toString(std::move(Err)) << '\n';
82   }
83 }
84 
85 int 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(argv[0]);
93   std::string driverPath = getExecutablePath(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(args.begin() + 1, args.end(),
101                                [](const char *a) { return a != nullptr; });
102   if (firstArg != args.end()) {
103     if (llvm::StringRef(args[1]).starts_with("-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("-fc1")) {
110       return executeFC1Tool(args);
111     }
112   }
113 
114   // Not in the frontend mode - continue in the compiler driver mode.
115 
116   // Create DiagnosticsEngine for the compiler driver
117   llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> diagOpts =
118       createAndPopulateDiagOpts(args);
119   llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagID(
120       new clang::DiagnosticIDs());
121   Fortran::frontend::TextDiagnosticPrinter *diagClient =
122       new Fortran::frontend::TextDiagnosticPrinter(llvm::errs(), &*diagOpts);
123 
124   diagClient->setPrefix(
125       std::string(llvm::sys::path::stem(getExecutablePath(args[0]))));
126 
127   clang::DiagnosticsEngine diags(diagID, &*diagOpts, diagClient);
128 
129   // Prepare the driver
130   clang::driver::Driver theDriver(driverPath,
131                                   llvm::sys::getDefaultTargetTriple(), diags,
132                                   "flang LLVM compiler");
133   theDriver.setTargetAndMode(targetandMode);
134 #ifdef FLANG_RUNTIME_F128_MATH_LIB
135   theDriver.setFlangF128MathLibrary(FLANG_RUNTIME_F128_MATH_LIB);
136 #endif
137   std::unique_ptr<clang::driver::Compilation> c(
138       theDriver.BuildCompilation(args));
139   llvm::SmallVector<std::pair<int, const clang::driver::Command *>, 4>
140       failingCommands;
141 
142   // Set the environment variable, FLANG_COMPILER_OPTIONS_STRING, to contain all
143   // the compiler options. This is intended for the frontend driver,
144   // flang -fc1, to enable the implementation of the COMPILER_OPTIONS
145   // intrinsic. To this end, the frontend driver requires the list of the
146   // original compiler options, which is not available through other means.
147   // TODO: This way of passing information between the compiler and frontend
148   // drivers is discouraged. We should find a better way not involving env
149   // variables.
150   std::string compilerOptsGathered;
151   llvm::raw_string_ostream os(compilerOptsGathered);
152   for (int i = 0; i < argc; ++i) {
153     os << argv[i];
154     if (i < argc - 1) {
155       os << ' ';
156     }
157   }
158 #ifdef _WIN32
159   _putenv_s("FLANG_COMPILER_OPTIONS_STRING", compilerOptsGathered.c_str());
160 #else
161   setenv("FLANG_COMPILER_OPTIONS_STRING", compilerOptsGathered.c_str(), 1);
162 #endif
163 
164   // Run the driver
165   int res = 1;
166   bool isCrash = false;
167   res = theDriver.ExecuteCompilation(*c, failingCommands);
168 
169   for (const auto &p : failingCommands) {
170     int commandRes = p.first;
171     const clang::driver::Command *failingCommand = p.second;
172     if (!res)
173       res = commandRes;
174 
175     // If result status is < 0 (e.g. when sys::ExecuteAndWait returns -1),
176     // then the driver command signalled an error. On Windows, abort will
177     // return an exit code of 3. In these cases, generate additional diagnostic
178     // information if possible.
179     isCrash = commandRes < 0;
180 #ifdef _WIN32
181     isCrash |= commandRes == 3;
182 #endif
183     if (isCrash) {
184       theDriver.generateCompilationDiagnostics(*c, *failingCommand);
185       break;
186     }
187   }
188 
189   diags.getClient()->finish();
190 
191   // If we have multiple failing commands, we return the result of the first
192   // failing command.
193   return res;
194 }
195