1 //===--- Job.cpp - Command to Execute -------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "clang/Driver/Driver.h"
11 #include "clang/Driver/DriverDiagnostic.h"
12 #include "clang/Driver/Job.h"
13 #include "clang/Driver/Tool.h"
14 #include "clang/Driver/ToolChain.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/ADT/StringSwitch.h"
18 #include "llvm/Support/Program.h"
19 #include "llvm/Support/raw_ostream.h"
20 #include <cassert>
21 using namespace clang::driver;
22 using llvm::raw_ostream;
23 using llvm::StringRef;
24 
25 Job::~Job() {}
26 
27 Command::Command(const Action &_Source, const Tool &_Creator,
28                  const char *_Executable,
29                  const ArgStringList &_Arguments)
30     : Job(CommandClass), Source(_Source), Creator(_Creator),
31       Executable(_Executable), Arguments(_Arguments) {}
32 
33 static int skipArgs(const char *Flag) {
34   // These flags are all of the form -Flag <Arg> and are treated as two
35   // arguments.  Therefore, we need to skip the flag and the next argument.
36   bool Res = llvm::StringSwitch<bool>(Flag)
37     .Cases("-I", "-MF", "-MT", "-MQ", true)
38     .Cases("-o", "-coverage-file", "-dependency-file", true)
39     .Cases("-fdebug-compilation-dir", "-idirafter", true)
40     .Cases("-include", "-include-pch", "-internal-isystem", true)
41     .Cases("-internal-externc-isystem", "-iprefix", "-iwithprefix", true)
42     .Cases("-iwithprefixbefore", "-isysroot", "-isystem", "-iquote", true)
43     .Cases("-resource-dir", "-serialize-diagnostic-file", true)
44     .Cases("-dwarf-debug-flags", "-ivfsoverlay", true)
45     .Default(false);
46 
47   // Match found.
48   if (Res)
49     return 2;
50 
51   // The remaining flags are treated as a single argument.
52 
53   // These flags are all of the form -Flag and have no second argument.
54   Res = llvm::StringSwitch<bool>(Flag)
55     .Cases("-M", "-MM", "-MG", "-MP", "-MD", true)
56     .Case("-MMD", true)
57     .Default(false);
58 
59   // Match found.
60   if (Res)
61     return 1;
62 
63   // These flags are treated as a single argument (e.g., -F<Dir>).
64   StringRef FlagRef(Flag);
65   if (FlagRef.startswith("-F") || FlagRef.startswith("-I") ||
66       FlagRef.startswith("-fmodules-cache-path="))
67     return 1;
68 
69   return 0;
70 }
71 
72 static bool quoteNextArg(const char *flag) {
73   return llvm::StringSwitch<bool>(flag)
74     .Case("-D", true)
75     .Default(false);
76 }
77 
78 static void PrintArg(raw_ostream &OS, const char *Arg, bool Quote) {
79   const bool Escape = std::strpbrk(Arg, "\"\\$");
80 
81   if (!Quote && !Escape) {
82     OS << Arg;
83     return;
84   }
85 
86   // Quote and escape. This isn't really complete, but good enough.
87   OS << '"';
88   while (const char c = *Arg++) {
89     if (c == '"' || c == '\\' || c == '$')
90       OS << '\\';
91     OS << c;
92   }
93   OS << '"';
94 }
95 
96 void Command::Print(raw_ostream &OS, const char *Terminator, bool Quote,
97                     bool CrashReport) const {
98   // Always quote the exe.
99   OS << ' ';
100   PrintArg(OS, Executable, /*Quote=*/true);
101 
102   for (size_t i = 0, e = Arguments.size(); i < e; ++i) {
103     const char *const Arg = Arguments[i];
104 
105     if (CrashReport) {
106       if (int Skip = skipArgs(Arg)) {
107         i += Skip - 1;
108         continue;
109       }
110     }
111 
112     OS << ' ';
113     PrintArg(OS, Arg, Quote);
114 
115     if (CrashReport && quoteNextArg(Arg) && i + 1 < e) {
116       OS << ' ';
117       PrintArg(OS, Arguments[++i], true);
118     }
119   }
120   OS << Terminator;
121 }
122 
123 int Command::Execute(const StringRef **Redirects, std::string *ErrMsg,
124                      bool *ExecutionFailed) const {
125   SmallVector<const char*, 128> Argv;
126   Argv.push_back(Executable);
127   for (size_t i = 0, e = Arguments.size(); i != e; ++i)
128     Argv.push_back(Arguments[i]);
129   Argv.push_back(nullptr);
130 
131   return llvm::sys::ExecuteAndWait(Executable, Argv.data(), /*env*/ nullptr,
132                                    Redirects, /*secondsToWait*/ 0,
133                                    /*memoryLimit*/ 0, ErrMsg, ExecutionFailed);
134 }
135 
136 FallbackCommand::FallbackCommand(const Action &Source_, const Tool &Creator_,
137                                  const char *Executable_,
138                                  const ArgStringList &Arguments_,
139                                  Command *Fallback_)
140     : Command(Source_, Creator_, Executable_, Arguments_), Fallback(Fallback_) {
141 }
142 
143 void FallbackCommand::Print(raw_ostream &OS, const char *Terminator,
144                             bool Quote, bool CrashReport) const {
145   Command::Print(OS, "", Quote, CrashReport);
146   OS << " ||";
147   Fallback->Print(OS, Terminator, Quote, CrashReport);
148 }
149 
150 static bool ShouldFallback(int ExitCode) {
151   // FIXME: We really just want to fall back for internal errors, such
152   // as when some symbol cannot be mangled, when we should be able to
153   // parse something but can't, etc.
154   return ExitCode != 0;
155 }
156 
157 int FallbackCommand::Execute(const StringRef **Redirects, std::string *ErrMsg,
158                              bool *ExecutionFailed) const {
159   int PrimaryStatus = Command::Execute(Redirects, ErrMsg, ExecutionFailed);
160   if (!ShouldFallback(PrimaryStatus))
161     return PrimaryStatus;
162 
163   // Clear ExecutionFailed and ErrMsg before falling back.
164   if (ErrMsg)
165     ErrMsg->clear();
166   if (ExecutionFailed)
167     *ExecutionFailed = false;
168 
169   const Driver &D = getCreator().getToolChain().getDriver();
170   D.Diag(diag::warn_drv_invoking_fallback) << Fallback->getExecutable();
171 
172   int SecondaryStatus = Fallback->Execute(Redirects, ErrMsg, ExecutionFailed);
173   return SecondaryStatus;
174 }
175 
176 JobList::JobList() : Job(JobListClass) {}
177 
178 JobList::~JobList() {
179   for (iterator it = begin(), ie = end(); it != ie; ++it)
180     delete *it;
181 }
182 
183 void JobList::Print(raw_ostream &OS, const char *Terminator, bool Quote,
184                     bool CrashReport) const {
185   for (const_iterator it = begin(), ie = end(); it != ie; ++it)
186     (*it)->Print(OS, Terminator, Quote, CrashReport);
187 }
188 
189 void JobList::clear() {
190   DeleteContainerPointers(Jobs);
191 }
192