Driver: Implement basic --help text.
- PR3875.
- <rdar://problem/6615249> [driver] ccc should support some form of
--help
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68148 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index a51e4bd..84e4cea 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -225,6 +225,71 @@
}
}
+static std::string getOptionHelpName(const OptTable &Opts, options::ID Id) {
+ std::string Name = Opts.getOptionName(Id);
+
+ // Add metavar, if used.
+ switch (Opts.getOptionKind(Id)) {
+ case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
+ assert(0 && "Invalid option with help text.");
+
+ case Option::MultiArgClass: case Option::JoinedAndSeparateClass:
+ assert(0 && "Cannot print metavar for this kind of option.");
+
+ case Option::FlagClass:
+ break;
+
+ case Option::SeparateClass: case Option::JoinedOrSeparateClass:
+ Name += ' ';
+ // FALLTHROUGH
+ case Option::JoinedClass: case Option::CommaJoinedClass:
+ Name += Opts.getOptionMetaVar(Id);
+ break;
+ }
+
+ return Name;
+}
+
+void Driver::PrintHelp() const {
+ llvm::raw_ostream &OS = llvm::outs();
+
+ OS << "OVERVIEW: clang \"gcc-compatible\" driver\n";
+ OS << '\n';
+ OS << "USAGE: " << Name << " [options] <input files>\n";
+ OS << '\n';
+ OS << "OPTIONS:\n";
+
+ // Render help text into (option, help) pairs.
+ std::vector< std::pair<std::string, const char*> > OptionHelp;
+
+ for (unsigned i = options::OPT_INPUT, e = options::LastOption; i != e; ++i) {
+ options::ID Id = (options::ID) i;
+ if (const char *Text = getOpts().getOptionHelpText(Id))
+ OptionHelp.push_back(std::make_pair(getOptionHelpName(getOpts(), Id),
+ Text));
+ }
+
+ // Find the maximum option length.
+ unsigned OptionFieldWidth = 0;
+ for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
+ // Limit the amount of padding we are willing to give up for
+ // alignment.
+ unsigned Length = OptionHelp[i].first.size();
+ if (Length <= 23)
+ OptionFieldWidth = std::max(OptionFieldWidth, Length);
+ }
+
+ for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
+ const std::string &Option = OptionHelp[i].first;
+ OS << " " << Option;
+ for (int j = Option.length(), e = OptionFieldWidth; j < e; ++j)
+ OS << ' ';
+ OS << ' ' << OptionHelp[i].second << '\n';
+ }
+
+ OS.flush();
+}
+
void Driver::PrintVersion(const Compilation &C) const {
static char buf[] = "$URL$";
char *zap = strstr(buf, "/lib/Driver");
@@ -252,6 +317,12 @@
// The order these options are handled in in gcc is all over the
// place, but we don't expect inconsistencies w.r.t. that to matter
// in practice.
+
+ if (C.getArgs().hasArg(options::OPT__help)) {
+ PrintHelp();
+ return false;
+ }
+
if (C.getArgs().hasArg(options::OPT_v) ||
C.getArgs().hasArg(options::OPT__HASH_HASH_HASH)) {
PrintVersion(C);
@@ -276,6 +347,7 @@
llvm::outs() << *it;
}
llvm::outs() << "\n";
+ return false;
}
// FIXME: The following handlers should use a callback mechanism, we