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 #include "clang/Driver/Driver.h"
14 #include "flang/Frontend/CompilerInvocation.h"
15 #include "flang/Frontend/TextDiagnosticPrinter.h"
16 #include "clang/Basic/Diagnostic.h"
17 #include "clang/Basic/DiagnosticIDs.h"
18 #include "clang/Basic/DiagnosticOptions.h"
19 #include "clang/Driver/Compilation.h"
20 #include "llvm/ADT/ArrayRef.h"
21 #include "llvm/ADT/IntrusiveRefCntPtr.h"
22 #include "llvm/Option/ArgList.h"
23 #include "llvm/Support/Host.h"
24 #include "llvm/Support/InitLLVM.h"
25 #include "llvm/Support/VirtualFileSystem.h"
26 
27 using llvm::StringRef;
28 
29 // main frontend method. Lives inside fc1_main.cpp
30 extern int fc1_main(llvm::ArrayRef<const char *> argv, const char *argv0);
31 
32 std::string GetExecutablePath(const char *argv0) {
33   // This just needs to be some symbol in the binary
34   void *p = (void *)(intptr_t)GetExecutablePath;
35   return llvm::sys::fs::getMainExecutable(argv0, p);
36 }
37 
38 // This lets us create the DiagnosticsEngine with a properly-filled-out
39 // DiagnosticOptions instance
40 static clang::DiagnosticOptions *CreateAndPopulateDiagOpts(
41     llvm::ArrayRef<const char *> argv) {
42   auto *diagOpts = new clang::DiagnosticOptions;
43 
44   // Ignore missingArgCount and the return value of ParseDiagnosticArgs.
45   // Any errors that would be diagnosed here will also be diagnosed later,
46   // when the DiagnosticsEngine actually exists.
47   unsigned missingArgIndex, missingArgCount;
48   llvm::opt::InputArgList args = clang::driver::getDriverOptTable().ParseArgs(
49       argv.slice(1), missingArgIndex, missingArgCount,
50       /*FlagsToInclude=*/clang::driver::options::FlangOption);
51 
52   (void)Fortran::frontend::ParseDiagnosticArgs(*diagOpts, args);
53 
54   return diagOpts;
55 }
56 
57 static int ExecuteFC1Tool(llvm::SmallVectorImpl<const char *> &argV) {
58   llvm::StringRef tool = argV[1];
59   if (tool == "-fc1")
60     return fc1_main(makeArrayRef(argV).slice(2), argV[0]);
61 
62   // Reject unknown tools.
63   // ATM it only supports fc1. Any fc1[*] is rejected.
64   llvm::errs() << "error: unknown integrated tool '" << tool << "'. "
65                << "Valid tools include '-fc1'.\n";
66   return 1;
67 }
68 
69 int main(int argc, const char **argv) {
70 
71   // Initialize variables to call the driver
72   llvm::InitLLVM x(argc, argv);
73   llvm::SmallVector<const char *, 256> args(argv, argv + argc);
74 
75   clang::driver::ParsedClangName targetandMode("flang", "--driver-mode=flang");
76   std::string driverPath = GetExecutablePath(args[0]);
77 
78   // Check if flang-new is in the frontend mode
79   auto firstArg = std::find_if(
80       args.begin() + 1, args.end(), [](const char *a) { return a != nullptr; });
81   if (firstArg != args.end()) {
82     if (llvm::StringRef(args[1]).startswith("-cc1")) {
83       llvm::errs() << "error: unknown integrated tool '" << args[1] << "'. "
84                    << "Valid tools include '-fc1'.\n";
85       return 1;
86     }
87     // Call flang-new frontend
88     if (llvm::StringRef(args[1]).startswith("-fc1")) {
89       return ExecuteFC1Tool(args);
90     }
91   }
92 
93   // Not in the frontend mode - continue in the compiler driver mode.
94 
95   // Create DiagnosticsEngine for the compiler driver
96   llvm::IntrusiveRefCntPtr<clang::DiagnosticOptions> diagOpts =
97       CreateAndPopulateDiagOpts(args);
98   llvm::IntrusiveRefCntPtr<clang::DiagnosticIDs> diagID(
99       new clang::DiagnosticIDs());
100   Fortran::frontend::TextDiagnosticPrinter *diagClient =
101       new Fortran::frontend::TextDiagnosticPrinter(llvm::errs(), &*diagOpts);
102 
103   diagClient->set_prefix(
104       std::string(llvm::sys::path::stem(GetExecutablePath(args[0]))));
105 
106   clang::DiagnosticsEngine diags(diagID, &*diagOpts, diagClient);
107 
108   // Prepare the driver
109   clang::driver::Driver theDriver(driverPath,
110       llvm::sys::getDefaultTargetTriple(), diags, "flang LLVM compiler");
111   theDriver.setTargetAndMode(targetandMode);
112   std::unique_ptr<clang::driver::Compilation> c(
113       theDriver.BuildCompilation(args));
114   llvm::SmallVector<std::pair<int, const clang::driver::Command *>, 4>
115       failingCommands;
116 
117   // Run the driver
118   int res = 1;
119   bool isCrash = false;
120   res = theDriver.ExecuteCompilation(*c, failingCommands);
121 
122   for (const auto &p : failingCommands) {
123     int CommandRes = p.first;
124     const clang::driver::Command *failingCommand = p.second;
125     if (!res)
126       res = CommandRes;
127 
128     // If result status is < 0 (e.g. when sys::ExecuteAndWait returns -1),
129     // then the driver command signalled an error. On Windows, abort will
130     // return an exit code of 3. In these cases, generate additional diagnostic
131     // information if possible.
132     isCrash = CommandRes < 0;
133 #ifdef _WIN32
134     isCrash |= CommandRes == 3;
135 #endif
136     if (isCrash) {
137       theDriver.generateCompilationDiagnostics(*c, *failingCommand);
138       break;
139     }
140   }
141 
142   diags.getClient()->finish();
143 
144   // If we have multiple failing commands, we return the result of the first
145   // failing command.
146   return res;
147 }
148