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//===-- ShellUtility.cpp --------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "llbuild/Basic/ShellUtility.h"
#include "llvm/ADT/SmallString.h"
using namespace llvm;
namespace llbuild {
namespace basic {
#if defined(_WIN32)
std::string formatWindowsCommandArg(StringRef string) {
// Windows escaping, adapted from Daniel Colascione's "Everyone quotes
// command line arguments the wrong way" - Microsoft Developer Blog
const std::string needsQuote = " \t\n\v\"";
if (string.find_first_of(needsQuote) == std::string::npos) {
return string;
}
// To escape the command line, we surround the argument with quotes. However
// the complication comes due to how the Windows command line parser treats
// backslashes (\) and quotes (")
//
// - \ is normally treated as a literal backslash
// - e.g. foo\bar\baz => foo\bar\baz
// - However, the sequence \" is treated as a literal "
// - e.g. foo\"bar => foo"bar
//
// But then what if we are given a path that ends with a \? Surrounding
// foo\bar\ with " would be "foo\bar\" which would be an unterminated string
// since it ends on a literal quote. To allow this case the parser treats:
//
// - \\" as \ followed by the " metachar
// - \\\" as \ followed by a literal "
// - In general:
// - 2n \ followed by " => n \ followed by the " metachar
// - 2n+1 \ followed by " => n \ followed by a literal "
std::string escaped = "\"";
for (auto i = std::begin(string); i != std::end(string); ++i) {
int numBackslashes = 0;
while (i != string.end() && *i == '\\') {
++i;
++numBackslashes;
}
if (i == string.end()) {
// String ends with a backslash e.g. foo\bar\, escape all the backslashes
// then add the metachar " below
escaped.append(numBackslashes * 2, '\\');
break;
} else if (*i == '"') {
// This is a string of \ followed by a " e.g. foo\"bar. Escape the
// backslashes and the quote
escaped.append(numBackslashes * 2 + 1, '\\');
escaped.push_back(*i);
} else {
// These are just literal backslashes
escaped.append(numBackslashes, '\\');
escaped.push_back(*i);
}
}
escaped.push_back('"');
return escaped;
}
std::string formatWindowsCommandString(std::vector<std::string> args) {
std::string commandLine;
for (auto& arg : args)
commandLine += formatWindowsCommandArg(arg) + " ";
if (commandLine.size())
commandLine.pop_back();
return commandLine;
}
#endif
void appendShellEscapedString(llvm::raw_ostream& os, StringRef string) {
#if defined(_WIN32)
os << formatWindowsCommandArg(string);
return;
#else
static const std::string whitelist = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890-_/:@#%+=.,";
auto pos = string.find_first_not_of(whitelist);
// We don't need any escaping just append the string and return.
if (pos == std::string::npos) {
os << string;
return;
}
std::string escQuote = "'";
// We only need to escape the single quote, if it isn't present we can
// escape using single quotes.
auto singleQuotePos = string.find_first_of("'" , pos);
if (singleQuotePos == std::string::npos) {
os << "'" << string << "'";
return;
}
// Otherwise iterate and escape all the single quotes.
os << "'";
os << string.slice(0, singleQuotePos);
for (auto idx = singleQuotePos; idx < string.size(); idx++) {
if (string[idx] == '\'') {
os << "'\\''";
} else {
os << string[idx];
}
}
os << "'";
#endif
}
std::string shellEscaped(StringRef string) {
SmallString<16> out;
llvm::raw_svector_ostream os(out);
appendShellEscapedString(os, string);
return out.str();
}
}
}
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