flang/tools/flang-driver/driver.cpp

   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("flang", "--driver-mode=flang");
  92   std::string driverPath = getExecutablePath(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(args.begin() + 1, args.end(),
 100                                [](const char *a) { return a != nullptr; });
 101   if (firstArg != args.end()) {
 102     if (llvm::StringRef(args[1]).starts_with("-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("-fc1")) {
 109       return executeFC1Tool(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(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(getExecutablePath(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));
 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("FLANG_COMPILER_OPTIONS_STRING", compilerOptsGathered.c_str(), 1);
 161 #endif
 162
 163   // Run the driver
 164   int res = 1;
 165   bool isCrash = false;
 166   res = theDriver.ExecuteCompilation(*c, 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, *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 }