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/Host.h"
29 #include "llvm/Support/InitLLVM.h"
30 #include "llvm/Support/VirtualFileSystem.h"
31 
32 using llvm::StringRef;
33 
34 // main frontend method. Lives inside fc1_main.cpp
35 extern int fc1_main(llvm::ArrayRef<const char *> argv, const char *argv0);
36 
37 std::string getExecutablePath(const char *argv0) {
38   // This just needs to be some symbol in the binary
39   void *p = (void *)(intptr_t)getExecutablePath;
40   return llvm::sys::fs::getMainExecutable(argv0, p);
41 }
42 
43 // This lets us create the DiagnosticsEngine with a properly-filled-out
44 // DiagnosticOptions instance
45 static clang::DiagnosticOptions *
46 createAndPopulateDiagOpts(llvm::ArrayRef<const char *> argv) {
47   auto *diagOpts = new clang::DiagnosticOptions;
48 
49   // Ignore missingArgCount and the return value of ParseDiagnosticArgs.
50   // Any errors that would be diagnosed here will also be diagnosed later,
51   // when the DiagnosticsEngine actually exists.
52   unsigned missingArgIndex, missingArgCount;
53   llvm::opt::InputArgList args = clang::driver::getDriverOptTable().ParseArgs(
54       argv.slice(1), missingArgIndex, missingArgCount,
55       /*FlagsToInclude=*/clang::driver::options::FlangOption);
56 
57   (void)Fortran::frontend::parseDiagnosticArgs(*diagOpts, args);
58 
59   return diagOpts;
60 }
61 
62 static int executeFC1Tool(llvm::SmallVectorImpl<const char *> &argV) {
63   llvm::StringRef tool = argV[1];
64   if (tool == "-fc1")
65     return fc1_main(makeArrayRef(argV).slice(2), argV[0]);
66 
67   // Reject unknown tools.
68   // ATM it only supports fc1. Any fc1[*] is rejected.
69   llvm::errs() << "error: unknown integrated tool '" << tool << "'. "
70                << "Valid tools include '-fc1'.\n";
71   return 1;
72 }
73 
74 int main(int argc, const char **argv) {
75 
76   // Initialize variables to call the driver
77   llvm::InitLLVM x(argc, argv);
78   llvm::SmallVector<const char *, 256> args(argv, argv + argc);
79 
80   clang::driver::ParsedClangName targetandMode("flang", "--driver-mode=flang");
81   std::string driverPath = getExecutablePath(args[0]);
82 
83   // Check if flang-new is in the frontend mode
84   auto firstArg = std::find_if(
85       args.begin() + 1, args.end(), [](const char *a) { return a != nullptr; });
86   if (firstArg != args.end()) {
87     if (llvm::StringRef(args[1]).startswith("-cc1")) {
88       llvm::errs() << "error: unknown integrated tool '" << args[1] << "'. "
89                    << "Valid tools include '-fc1'.\n";
90       return 1;
91     }
92     // Call flang-new frontend
93     if (llvm::StringRef(args[1]).startswith("-fc1")) {
94       return executeFC1Tool(args);
95     }
96   }
97 
98   // Not in the frontend mode - continue in the compiler driver mode.
99 
100   // Create DiagnosticsEngine for the compiler driver
101   llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> diagOpts =
102       createAndPopulateDiagOpts(args);
103   llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagID(
104       new clang::DiagnosticIDs());
105   Fortran::frontend::TextDiagnosticPrinter *diagClient =
106       new Fortran::frontend::TextDiagnosticPrinter(llvm::errs(), &*diagOpts);
107 
108   diagClient->setPrefix(
109       std::string(llvm::sys::path::stem(getExecutablePath(args[0]))));
110 
111   clang::DiagnosticsEngine diags(diagID, &*diagOpts, diagClient);
112 
113   // Prepare the driver
114   clang::driver::Driver theDriver(driverPath,
115       llvm::sys::getDefaultTargetTriple(), diags, "flang LLVM compiler");
116   theDriver.setTargetAndMode(targetandMode);
117   std::unique_ptr<clang::driver::Compilation> c(
118       theDriver.BuildCompilation(args));
119   llvm::SmallVector<std::pair<int, const clang::driver::Command *>, 4>
120       failingCommands;
121 
122   // Run the driver
123   int res = 1;
124   bool isCrash = false;
125   res = theDriver.ExecuteCompilation(*c, failingCommands);
126 
127   for (const auto &p : failingCommands) {
128     int commandRes = p.first;
129     const clang::driver::Command *failingCommand = p.second;
130     if (!res)
131       res = commandRes;
132 
133     // If result status is < 0 (e.g. when sys::ExecuteAndWait returns -1),
134     // then the driver command signalled an error. On Windows, abort will
135     // return an exit code of 3. In these cases, generate additional diagnostic
136     // information if possible.
137     isCrash = commandRes < 0;
138 #ifdef _WIN32
139     isCrash |= commandRes == 3;
140 #endif
141     if (isCrash) {
142       theDriver.generateCompilationDiagnostics(*c, *failingCommand);
143       break;
144     }
145   }
146 
147   diags.getClient()->finish();
148 
149   // If we have multiple failing commands, we return the result of the first
150   // failing command.
151   return res;
152 }
153