llvm-toolchain-10/lldb/source/Utility/Args.cpp

687 lines
19 KiB
C++

//===-- Args.cpp ------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/Args.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/StringList.h"
#include "llvm/ADT/StringSwitch.h"
using namespace lldb;
using namespace lldb_private;
// A helper function for argument parsing.
// Parses the initial part of the first argument using normal double quote
// rules: backslash escapes the double quote and itself. The parsed string is
// appended to the second argument. The function returns the unparsed portion
// of the string, starting at the closing quote.
static llvm::StringRef ParseDoubleQuotes(llvm::StringRef quoted,
std::string &result) {
// Inside double quotes, '\' and '"' are special.
static const char *k_escapable_characters = "\"\\";
while (true) {
// Skip over over regular characters and append them.
size_t regular = quoted.find_first_of(k_escapable_characters);
result += quoted.substr(0, regular);
quoted = quoted.substr(regular);
// If we have reached the end of string or the closing quote, we're done.
if (quoted.empty() || quoted.front() == '"')
break;
// We have found a backslash.
quoted = quoted.drop_front();
if (quoted.empty()) {
// A lone backslash at the end of string, let's just append it.
result += '\\';
break;
}
// If the character after the backslash is not a whitelisted escapable
// character, we leave the character sequence untouched.
if (strchr(k_escapable_characters, quoted.front()) == nullptr)
result += '\\';
result += quoted.front();
quoted = quoted.drop_front();
}
return quoted;
}
static size_t ArgvToArgc(const char **argv) {
if (!argv)
return 0;
size_t count = 0;
while (*argv++)
++count;
return count;
}
// Trims all whitespace that can separate command line arguments from the left
// side of the string.
static llvm::StringRef ltrimForArgs(llvm::StringRef str) {
static const char *k_space_separators = " \t";
return str.ltrim(k_space_separators);
}
// A helper function for SetCommandString. Parses a single argument from the
// command string, processing quotes and backslashes in a shell-like manner.
// The function returns a tuple consisting of the parsed argument, the quote
// char used, and the unparsed portion of the string starting at the first
// unqouted, unescaped whitespace character.
static std::tuple<std::string, char, llvm::StringRef>
ParseSingleArgument(llvm::StringRef command) {
// Argument can be split into multiple discontiguous pieces, for example:
// "Hello ""World"
// this would result in a single argument "Hello World" (without the quotes)
// since the quotes would be removed and there is not space between the
// strings.
std::string arg;
// Since we can have multiple quotes that form a single command in a command
// like: "Hello "world'!' (which will make a single argument "Hello world!")
// we remember the first quote character we encounter and use that for the
// quote character.
char first_quote_char = '\0';
bool arg_complete = false;
do {
// Skip over over regular characters and append them.
size_t regular = command.find_first_of(" \t\r\"'`\\");
arg += command.substr(0, regular);
command = command.substr(regular);
if (command.empty())
break;
char special = command.front();
command = command.drop_front();
switch (special) {
case '\\':
if (command.empty()) {
arg += '\\';
break;
}
// If the character after the backslash is not a whitelisted escapable
// character, we leave the character sequence untouched.
if (strchr(" \t\\'\"`", command.front()) == nullptr)
arg += '\\';
arg += command.front();
command = command.drop_front();
break;
case ' ':
case '\t':
case '\r':
// We are not inside any quotes, we just found a space after an argument.
// We are done.
arg_complete = true;
break;
case '"':
case '\'':
case '`':
// We found the start of a quote scope.
if (first_quote_char == '\0')
first_quote_char = special;
if (special == '"')
command = ParseDoubleQuotes(command, arg);
else {
// For single quotes, we simply skip ahead to the matching quote
// character (or the end of the string).
size_t quoted = command.find(special);
arg += command.substr(0, quoted);
command = command.substr(quoted);
}
// If we found a closing quote, skip it.
if (!command.empty())
command = command.drop_front();
break;
}
} while (!arg_complete);
return std::make_tuple(arg, first_quote_char, command);
}
Args::ArgEntry::ArgEntry(llvm::StringRef str, char quote) : quote(quote) {
size_t size = str.size();
ptr.reset(new char[size + 1]);
::memcpy(data(), str.data() ? str.data() : "", size);
ptr[size] = 0;
}
// Args constructor
Args::Args(llvm::StringRef command) { SetCommandString(command); }
Args::Args(const Args &rhs) { *this = rhs; }
Args::Args(const StringList &list) : Args() {
for (const std::string &arg : list)
AppendArgument(arg);
}
Args &Args::operator=(const Args &rhs) {
Clear();
m_argv.clear();
m_entries.clear();
for (auto &entry : rhs.m_entries) {
m_entries.emplace_back(entry.ref(), entry.quote);
m_argv.push_back(m_entries.back().data());
}
m_argv.push_back(nullptr);
return *this;
}
// Destructor
Args::~Args() {}
void Args::Dump(Stream &s, const char *label_name) const {
if (!label_name)
return;
int i = 0;
for (auto &entry : m_entries) {
s.Indent();
s.Format("{0}[{1}]=\"{2}\"\n", label_name, i++, entry.ref());
}
s.Format("{0}[{1}]=NULL\n", label_name, i);
s.EOL();
}
bool Args::GetCommandString(std::string &command) const {
command.clear();
for (size_t i = 0; i < m_entries.size(); ++i) {
if (i > 0)
command += ' ';
command += m_entries[i].ref();
}
return !m_entries.empty();
}
bool Args::GetQuotedCommandString(std::string &command) const {
command.clear();
for (size_t i = 0; i < m_entries.size(); ++i) {
if (i > 0)
command += ' ';
if (m_entries[i].quote) {
command += m_entries[i].quote;
command += m_entries[i].ref();
command += m_entries[i].quote;
} else {
command += m_entries[i].ref();
}
}
return !m_entries.empty();
}
void Args::SetCommandString(llvm::StringRef command) {
Clear();
m_argv.clear();
command = ltrimForArgs(command);
std::string arg;
char quote;
while (!command.empty()) {
std::tie(arg, quote, command) = ParseSingleArgument(command);
m_entries.emplace_back(arg, quote);
m_argv.push_back(m_entries.back().data());
command = ltrimForArgs(command);
}
m_argv.push_back(nullptr);
}
size_t Args::GetArgumentCount() const { return m_entries.size(); }
const char *Args::GetArgumentAtIndex(size_t idx) const {
if (idx < m_argv.size())
return m_argv[idx];
return nullptr;
}
char **Args::GetArgumentVector() {
assert(!m_argv.empty());
// TODO: functions like execve and posix_spawnp exhibit undefined behavior
// when argv or envp is null. So the code below is actually wrong. However,
// other code in LLDB depends on it being null. The code has been acting
// this way for some time, so it makes sense to leave it this way until
// someone has the time to come along and fix it.
return (m_argv.size() > 1) ? m_argv.data() : nullptr;
}
const char **Args::GetConstArgumentVector() const {
assert(!m_argv.empty());
return (m_argv.size() > 1) ? const_cast<const char **>(m_argv.data())
: nullptr;
}
void Args::Shift() {
// Don't pop the last NULL terminator from the argv array
if (m_entries.empty())
return;
m_argv.erase(m_argv.begin());
m_entries.erase(m_entries.begin());
}
void Args::Unshift(llvm::StringRef arg_str, char quote_char) {
InsertArgumentAtIndex(0, arg_str, quote_char);
}
void Args::AppendArguments(const Args &rhs) {
assert(m_argv.size() == m_entries.size() + 1);
assert(m_argv.back() == nullptr);
m_argv.pop_back();
for (auto &entry : rhs.m_entries) {
m_entries.emplace_back(entry.ref(), entry.quote);
m_argv.push_back(m_entries.back().data());
}
m_argv.push_back(nullptr);
}
void Args::AppendArguments(const char **argv) {
size_t argc = ArgvToArgc(argv);
assert(m_argv.size() == m_entries.size() + 1);
assert(m_argv.back() == nullptr);
m_argv.pop_back();
for (auto arg : llvm::makeArrayRef(argv, argc)) {
m_entries.emplace_back(arg, '\0');
m_argv.push_back(m_entries.back().data());
}
m_argv.push_back(nullptr);
}
void Args::AppendArgument(llvm::StringRef arg_str, char quote_char) {
InsertArgumentAtIndex(GetArgumentCount(), arg_str, quote_char);
}
void Args::InsertArgumentAtIndex(size_t idx, llvm::StringRef arg_str,
char quote_char) {
assert(m_argv.size() == m_entries.size() + 1);
assert(m_argv.back() == nullptr);
if (idx > m_entries.size())
return;
m_entries.emplace(m_entries.begin() + idx, arg_str, quote_char);
m_argv.insert(m_argv.begin() + idx, m_entries[idx].data());
}
void Args::ReplaceArgumentAtIndex(size_t idx, llvm::StringRef arg_str,
char quote_char) {
assert(m_argv.size() == m_entries.size() + 1);
assert(m_argv.back() == nullptr);
if (idx >= m_entries.size())
return;
m_entries[idx] = ArgEntry(arg_str, quote_char);
m_argv[idx] = m_entries[idx].data();
}
void Args::DeleteArgumentAtIndex(size_t idx) {
if (idx >= m_entries.size())
return;
m_argv.erase(m_argv.begin() + idx);
m_entries.erase(m_entries.begin() + idx);
}
void Args::SetArguments(size_t argc, const char **argv) {
Clear();
auto args = llvm::makeArrayRef(argv, argc);
m_entries.resize(argc);
m_argv.resize(argc + 1);
for (size_t i = 0; i < args.size(); ++i) {
char quote =
((args[i][0] == '\'') || (args[i][0] == '"') || (args[i][0] == '`'))
? args[i][0]
: '\0';
m_entries[i] = ArgEntry(args[i], quote);
m_argv[i] = m_entries[i].data();
}
}
void Args::SetArguments(const char **argv) {
SetArguments(ArgvToArgc(argv), argv);
}
void Args::Clear() {
m_entries.clear();
m_argv.clear();
m_argv.push_back(nullptr);
}
const char *Args::GetShellSafeArgument(const FileSpec &shell,
const char *unsafe_arg,
std::string &safe_arg) {
struct ShellDescriptor {
ConstString m_basename;
const char *m_escapables;
};
static ShellDescriptor g_Shells[] = {{ConstString("bash"), " '\"<>()&"},
{ConstString("tcsh"), " '\"<>()&$"},
{ConstString("sh"), " '\"<>()&"}};
// safe minimal set
const char *escapables = " '\"";
if (auto basename = shell.GetFilename()) {
for (const auto &Shell : g_Shells) {
if (Shell.m_basename == basename) {
escapables = Shell.m_escapables;
break;
}
}
}
safe_arg.assign(unsafe_arg);
size_t prev_pos = 0;
while (prev_pos < safe_arg.size()) {
// Escape spaces and quotes
size_t pos = safe_arg.find_first_of(escapables, prev_pos);
if (pos != std::string::npos) {
safe_arg.insert(pos, 1, '\\');
prev_pos = pos + 2;
} else
break;
}
return safe_arg.c_str();
}
lldb::Encoding Args::StringToEncoding(llvm::StringRef s,
lldb::Encoding fail_value) {
return llvm::StringSwitch<lldb::Encoding>(s)
.Case("uint", eEncodingUint)
.Case("sint", eEncodingSint)
.Case("ieee754", eEncodingIEEE754)
.Case("vector", eEncodingVector)
.Default(fail_value);
}
uint32_t Args::StringToGenericRegister(llvm::StringRef s) {
if (s.empty())
return LLDB_INVALID_REGNUM;
uint32_t result = llvm::StringSwitch<uint32_t>(s)
.Case("pc", LLDB_REGNUM_GENERIC_PC)
.Case("sp", LLDB_REGNUM_GENERIC_SP)
.Case("fp", LLDB_REGNUM_GENERIC_FP)
.Cases("ra", "lr", LLDB_REGNUM_GENERIC_RA)
.Case("flags", LLDB_REGNUM_GENERIC_FLAGS)
.Case("arg1", LLDB_REGNUM_GENERIC_ARG1)
.Case("arg2", LLDB_REGNUM_GENERIC_ARG2)
.Case("arg3", LLDB_REGNUM_GENERIC_ARG3)
.Case("arg4", LLDB_REGNUM_GENERIC_ARG4)
.Case("arg5", LLDB_REGNUM_GENERIC_ARG5)
.Case("arg6", LLDB_REGNUM_GENERIC_ARG6)
.Case("arg7", LLDB_REGNUM_GENERIC_ARG7)
.Case("arg8", LLDB_REGNUM_GENERIC_ARG8)
.Default(LLDB_INVALID_REGNUM);
return result;
}
void Args::EncodeEscapeSequences(const char *src, std::string &dst) {
dst.clear();
if (src) {
for (const char *p = src; *p != '\0'; ++p) {
size_t non_special_chars = ::strcspn(p, "\\");
if (non_special_chars > 0) {
dst.append(p, non_special_chars);
p += non_special_chars;
if (*p == '\0')
break;
}
if (*p == '\\') {
++p; // skip the slash
switch (*p) {
case 'a':
dst.append(1, '\a');
break;
case 'b':
dst.append(1, '\b');
break;
case 'f':
dst.append(1, '\f');
break;
case 'n':
dst.append(1, '\n');
break;
case 'r':
dst.append(1, '\r');
break;
case 't':
dst.append(1, '\t');
break;
case 'v':
dst.append(1, '\v');
break;
case '\\':
dst.append(1, '\\');
break;
case '\'':
dst.append(1, '\'');
break;
case '"':
dst.append(1, '"');
break;
case '0':
// 1 to 3 octal chars
{
// Make a string that can hold onto the initial zero char, up to 3
// octal digits, and a terminating NULL.
char oct_str[5] = {'\0', '\0', '\0', '\0', '\0'};
int i;
for (i = 0; (p[i] >= '0' && p[i] <= '7') && i < 4; ++i)
oct_str[i] = p[i];
// We don't want to consume the last octal character since the main
// for loop will do this for us, so we advance p by one less than i
// (even if i is zero)
p += i - 1;
unsigned long octal_value = ::strtoul(oct_str, nullptr, 8);
if (octal_value <= UINT8_MAX) {
dst.append(1, static_cast<char>(octal_value));
}
}
break;
case 'x':
// hex number in the format
if (isxdigit(p[1])) {
++p; // Skip the 'x'
// Make a string that can hold onto two hex chars plus a
// NULL terminator
char hex_str[3] = {*p, '\0', '\0'};
if (isxdigit(p[1])) {
++p; // Skip the first of the two hex chars
hex_str[1] = *p;
}
unsigned long hex_value = strtoul(hex_str, nullptr, 16);
if (hex_value <= UINT8_MAX)
dst.append(1, static_cast<char>(hex_value));
} else {
dst.append(1, 'x');
}
break;
default:
// Just desensitize any other character by just printing what came
// after the '\'
dst.append(1, *p);
break;
}
}
}
}
}
void Args::ExpandEscapedCharacters(const char *src, std::string &dst) {
dst.clear();
if (src) {
for (const char *p = src; *p != '\0'; ++p) {
if (isprint(*p))
dst.append(1, *p);
else {
switch (*p) {
case '\a':
dst.append("\\a");
break;
case '\b':
dst.append("\\b");
break;
case '\f':
dst.append("\\f");
break;
case '\n':
dst.append("\\n");
break;
case '\r':
dst.append("\\r");
break;
case '\t':
dst.append("\\t");
break;
case '\v':
dst.append("\\v");
break;
case '\'':
dst.append("\\'");
break;
case '"':
dst.append("\\\"");
break;
case '\\':
dst.append("\\\\");
break;
default: {
// Just encode as octal
dst.append("\\0");
char octal_str[32];
snprintf(octal_str, sizeof(octal_str), "%o", *p);
dst.append(octal_str);
} break;
}
}
}
}
}
std::string Args::EscapeLLDBCommandArgument(const std::string &arg,
char quote_char) {
const char *chars_to_escape = nullptr;
switch (quote_char) {
case '\0':
chars_to_escape = " \t\\'\"`";
break;
case '"':
chars_to_escape = "$\"`\\";
break;
case '`':
case '\'':
return arg;
default:
assert(false && "Unhandled quote character");
return arg;
}
std::string res;
res.reserve(arg.size());
for (char c : arg) {
if (::strchr(chars_to_escape, c))
res.push_back('\\');
res.push_back(c);
}
return res;
}
OptionsWithRaw::OptionsWithRaw(llvm::StringRef arg_string) {
SetFromString(arg_string);
}
void OptionsWithRaw::SetFromString(llvm::StringRef arg_string) {
const llvm::StringRef original_args = arg_string;
arg_string = ltrimForArgs(arg_string);
std::string arg;
char quote;
// If the string doesn't start with a dash, we just have no options and just
// a raw part.
if (!arg_string.startswith("-")) {
m_suffix = original_args;
return;
}
bool found_suffix = false;
while (!arg_string.empty()) {
// The length of the prefix before parsing.
std::size_t prev_prefix_length = original_args.size() - arg_string.size();
// Parse the next argument from the remaining string.
std::tie(arg, quote, arg_string) = ParseSingleArgument(arg_string);
// If we get an unquoted '--' argument, then we reached the suffix part
// of the command.
Args::ArgEntry entry(arg, quote);
if (!entry.IsQuoted() && arg == "--") {
// The remaining line is the raw suffix, and the line we parsed so far
// needs to be interpreted as arguments.
m_has_args = true;
m_suffix = arg_string;
found_suffix = true;
// The length of the prefix after parsing.
std::size_t prefix_length = original_args.size() - arg_string.size();
// Take the string we know contains all the arguments and actually parse
// it as proper arguments.
llvm::StringRef prefix = original_args.take_front(prev_prefix_length);
m_args = Args(prefix);
m_arg_string = prefix;
// We also record the part of the string that contains the arguments plus
// the delimiter.
m_arg_string_with_delimiter = original_args.take_front(prefix_length);
// As the rest of the string became the raw suffix, we are done here.
break;
}
arg_string = ltrimForArgs(arg_string);
}
// If we didn't find a suffix delimiter, the whole string is the raw suffix.
if (!found_suffix) {
found_suffix = true;
m_suffix = original_args;
}
}