blob: 2647bd1f0cb20c38020c8b6dd389a87e0104bce5 [file] [log] [blame]
// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/flags.h"
#include <cctype>
#include <cerrno>
#include <cstdlib>
#include <sstream>
#include "src/allocation.h"
#include "src/base/functional.h"
#include "src/base/platform/platform.h"
#include "src/counters.h"
#include "src/cpu-features.h"
#include "src/memcopy.h"
#include "src/ostreams.h"
#include "src/utils.h"
#include "src/wasm/wasm-limits.h"
namespace v8 {
namespace internal {
// Define all of our flags.
#define FLAG_MODE_DEFINE
#include "src/flag-definitions.h" // NOLINT(build/include)
// Define all of our flags default values.
#define FLAG_MODE_DEFINE_DEFAULTS
#include "src/flag-definitions.h" // NOLINT(build/include)
namespace {
// This structure represents a single entry in the flag system, with a pointer
// to the actual flag, default value, comment, etc. This is designed to be POD
// initialized as to avoid requiring static constructors.
struct Flag {
enum FlagType {
TYPE_BOOL,
TYPE_MAYBE_BOOL,
TYPE_INT,
TYPE_UINT,
TYPE_UINT64,
TYPE_FLOAT,
TYPE_SIZE_T,
TYPE_STRING,
};
FlagType type_; // What type of flag, bool, int, or string.
const char* name_; // Name of the flag, ex "my_flag".
void* valptr_; // Pointer to the global flag variable.
const void* defptr_; // Pointer to the default value.
const char* cmt_; // A comment about the flags purpose.
bool owns_ptr_; // Does the flag own its string value?
FlagType type() const { return type_; }
const char* name() const { return name_; }
const char* comment() const { return cmt_; }
bool* bool_variable() const {
DCHECK(type_ == TYPE_BOOL);
return reinterpret_cast<bool*>(valptr_);
}
MaybeBoolFlag* maybe_bool_variable() const {
DCHECK(type_ == TYPE_MAYBE_BOOL);
return reinterpret_cast<MaybeBoolFlag*>(valptr_);
}
int* int_variable() const {
DCHECK(type_ == TYPE_INT);
return reinterpret_cast<int*>(valptr_);
}
unsigned int* uint_variable() const {
DCHECK(type_ == TYPE_UINT);
return reinterpret_cast<unsigned int*>(valptr_);
}
uint64_t* uint64_variable() const {
DCHECK(type_ == TYPE_UINT64);
return reinterpret_cast<uint64_t*>(valptr_);
}
double* float_variable() const {
DCHECK(type_ == TYPE_FLOAT);
return reinterpret_cast<double*>(valptr_);
}
size_t* size_t_variable() const {
DCHECK(type_ == TYPE_SIZE_T);
return reinterpret_cast<size_t*>(valptr_);
}
const char* string_value() const {
DCHECK(type_ == TYPE_STRING);
return *reinterpret_cast<const char**>(valptr_);
}
void set_string_value(const char* value, bool owns_ptr) {
DCHECK(type_ == TYPE_STRING);
const char** ptr = reinterpret_cast<const char**>(valptr_);
if (owns_ptr_ && *ptr != nullptr) DeleteArray(*ptr);
*ptr = value;
owns_ptr_ = owns_ptr;
}
bool bool_default() const {
DCHECK(type_ == TYPE_BOOL);
return *reinterpret_cast<const bool*>(defptr_);
}
int int_default() const {
DCHECK(type_ == TYPE_INT);
return *reinterpret_cast<const int*>(defptr_);
}
unsigned int uint_default() const {
DCHECK(type_ == TYPE_UINT);
return *reinterpret_cast<const unsigned int*>(defptr_);
}
uint64_t uint64_default() const {
DCHECK(type_ == TYPE_UINT64);
return *reinterpret_cast<const uint64_t*>(defptr_);
}
double float_default() const {
DCHECK(type_ == TYPE_FLOAT);
return *reinterpret_cast<const double*>(defptr_);
}
size_t size_t_default() const {
DCHECK(type_ == TYPE_SIZE_T);
return *reinterpret_cast<const size_t*>(defptr_);
}
const char* string_default() const {
DCHECK(type_ == TYPE_STRING);
return *reinterpret_cast<const char* const *>(defptr_);
}
// Compare this flag's current value against the default.
bool IsDefault() const {
switch (type_) {
case TYPE_BOOL:
return *bool_variable() == bool_default();
case TYPE_MAYBE_BOOL:
return maybe_bool_variable()->has_value == false;
case TYPE_INT:
return *int_variable() == int_default();
case TYPE_UINT:
return *uint_variable() == uint_default();
case TYPE_UINT64:
return *uint64_variable() == uint64_default();
case TYPE_FLOAT:
return *float_variable() == float_default();
case TYPE_SIZE_T:
return *size_t_variable() == size_t_default();
case TYPE_STRING: {
const char* str1 = string_value();
const char* str2 = string_default();
if (str2 == nullptr) return str1 == nullptr;
if (str1 == nullptr) return str2 == nullptr;
return strcmp(str1, str2) == 0;
}
}
UNREACHABLE();
}
// Set a flag back to it's default value.
void Reset() {
switch (type_) {
case TYPE_BOOL:
*bool_variable() = bool_default();
break;
case TYPE_MAYBE_BOOL:
*maybe_bool_variable() = MaybeBoolFlag::Create(false, false);
break;
case TYPE_INT:
*int_variable() = int_default();
break;
case TYPE_UINT:
*uint_variable() = uint_default();
break;
case TYPE_UINT64:
*uint64_variable() = uint64_default();
break;
case TYPE_FLOAT:
*float_variable() = float_default();
break;
case TYPE_SIZE_T:
*size_t_variable() = size_t_default();
break;
case TYPE_STRING:
set_string_value(string_default(), false);
break;
}
}
};
Flag flags[] = {
#define FLAG_MODE_META
#include "src/flag-definitions.h" // NOLINT(build/include)
};
const size_t num_flags = sizeof(flags) / sizeof(*flags);
} // namespace
static const char* Type2String(Flag::FlagType type) {
switch (type) {
case Flag::TYPE_BOOL: return "bool";
case Flag::TYPE_MAYBE_BOOL: return "maybe_bool";
case Flag::TYPE_INT: return "int";
case Flag::TYPE_UINT:
return "uint";
case Flag::TYPE_UINT64:
return "uint64";
case Flag::TYPE_FLOAT: return "float";
case Flag::TYPE_SIZE_T:
return "size_t";
case Flag::TYPE_STRING: return "string";
}
UNREACHABLE();
}
std::ostream& operator<<(std::ostream& os, const Flag& flag) { // NOLINT
switch (flag.type()) {
case Flag::TYPE_BOOL:
os << (*flag.bool_variable() ? "true" : "false");
break;
case Flag::TYPE_MAYBE_BOOL:
os << (flag.maybe_bool_variable()->has_value
? (flag.maybe_bool_variable()->value ? "true" : "false")
: "unset");
break;
case Flag::TYPE_INT:
os << *flag.int_variable();
break;
case Flag::TYPE_UINT:
os << *flag.uint_variable();
break;
case Flag::TYPE_UINT64:
os << *flag.uint64_variable();
break;
case Flag::TYPE_FLOAT:
os << *flag.float_variable();
break;
case Flag::TYPE_SIZE_T:
os << *flag.size_t_variable();
break;
case Flag::TYPE_STRING: {
const char* str = flag.string_value();
os << (str ? str : "nullptr");
break;
}
}
return os;
}
// static
std::vector<const char*>* FlagList::argv() {
std::vector<const char*>* args = new std::vector<const char*>(8);
for (size_t i = 0; i < num_flags; ++i) {
Flag* f = &flags[i];
if (!f->IsDefault()) {
{
bool disabled = f->type() == Flag::TYPE_BOOL && !*f->bool_variable();
std::ostringstream os;
os << (disabled ? "--no" : "--") << f->name();
args->push_back(StrDup(os.str().c_str()));
}
if (f->type() != Flag::TYPE_BOOL) {
std::ostringstream os;
os << *f;
args->push_back(StrDup(os.str().c_str()));
}
}
}
return args;
}
inline char NormalizeChar(char ch) {
return ch == '_' ? '-' : ch;
}
// Helper function to parse flags: Takes an argument arg and splits it into
// a flag name and flag value (or nullptr if they are missing). negated is set
// if the arg started with "-no" or "--no". The buffer may be used to NUL-
// terminate the name, it must be large enough to hold any possible name.
static void SplitArgument(const char* arg, char* buffer, int buffer_size,
const char** name, const char** value,
bool* negated) {
*name = nullptr;
*value = nullptr;
*negated = false;
if (arg != nullptr && *arg == '-') {
// find the begin of the flag name
arg++; // remove 1st '-'
if (*arg == '-') {
arg++; // remove 2nd '-'
DCHECK_NE('\0', arg[0]); // '--' arguments are handled in the caller.
}
if (arg[0] == 'n' && arg[1] == 'o') {
arg += 2; // remove "no"
if (NormalizeChar(arg[0]) == '-') arg++; // remove dash after "no".
*negated = true;
}
*name = arg;
// find the end of the flag name
while (*arg != '\0' && *arg != '=')
arg++;
// get the value if any
if (*arg == '=') {
// make a copy so we can NUL-terminate flag name
size_t n = arg - *name;
CHECK(n < static_cast<size_t>(buffer_size)); // buffer is too small
MemCopy(buffer, *name, n);
buffer[n] = '\0';
*name = buffer;
// get the value
*value = arg + 1;
}
}
}
static bool EqualNames(const char* a, const char* b) {
for (int i = 0; NormalizeChar(a[i]) == NormalizeChar(b[i]); i++) {
if (a[i] == '\0') {
return true;
}
}
return false;
}
static Flag* FindFlag(const char* name) {
for (size_t i = 0; i < num_flags; ++i) {
if (EqualNames(name, flags[i].name()))
return &flags[i];
}
return nullptr;
}
template <typename T>
bool TryParseUnsigned(Flag* flag, const char* arg, const char* value,
char** endp, T* out_val) {
// We do not use strtoul because it accepts negative numbers.
// Rejects values >= 2**63 when T is 64 bits wide but that
// seems like an acceptable trade-off.
uint64_t max = static_cast<uint64_t>(std::numeric_limits<T>::max());
errno = 0;
int64_t val = static_cast<int64_t>(strtoll(value, endp, 10));
if (val < 0 || static_cast<uint64_t>(val) > max || errno != 0) {
PrintF(stderr,
"Error: Value for flag %s of type %s is out of bounds "
"[0-%" PRIu64 "]\n",
arg, Type2String(flag->type()), max);
return false;
}
*out_val = static_cast<T>(val);
return true;
}
// static
int FlagList::SetFlagsFromCommandLine(int* argc,
char** argv,
bool remove_flags) {
int return_code = 0;
// parse arguments
for (int i = 1; i < *argc;) {
int j = i; // j > 0
const char* arg = argv[i++];
// split arg into flag components
char buffer[1*KB];
const char* name;
const char* value;
bool negated;
SplitArgument(arg, buffer, sizeof buffer, &name, &value, &negated);
if (name != nullptr) {
// lookup the flag
Flag* flag = FindFlag(name);
if (flag == nullptr) {
if (remove_flags) {
// We don't recognize this flag but since we're removing
// the flags we recognize we assume that the remaining flags
// will be processed somewhere else so this flag might make
// sense there.
continue;
} else {
PrintF(stderr, "Error: unrecognized flag %s\n", arg);
return_code = j;
break;
}
}
// if we still need a flag value, use the next argument if available
if (flag->type() != Flag::TYPE_BOOL &&
flag->type() != Flag::TYPE_MAYBE_BOOL && value == nullptr) {
if (i < *argc) {
value = argv[i++];
}
if (!value) {
PrintF(stderr, "Error: missing value for flag %s of type %s\n", arg,
Type2String(flag->type()));
return_code = j;
break;
}
}
// set the flag
char* endp = const_cast<char*>(""); // *endp is only read
switch (flag->type()) {
case Flag::TYPE_BOOL:
*flag->bool_variable() = !negated;
break;
case Flag::TYPE_MAYBE_BOOL:
*flag->maybe_bool_variable() = MaybeBoolFlag::Create(true, !negated);
break;
case Flag::TYPE_INT:
*flag->int_variable() = static_cast<int>(strtol(value, &endp, 10));
break;
case Flag::TYPE_UINT:
if (!TryParseUnsigned(flag, arg, value, &endp,
flag->uint_variable())) {
return_code = j;
}
break;
case Flag::TYPE_UINT64:
if (!TryParseUnsigned(flag, arg, value, &endp,
flag->uint64_variable())) {
return_code = j;
}
break;
case Flag::TYPE_FLOAT:
*flag->float_variable() = strtod(value, &endp);
break;
case Flag::TYPE_SIZE_T:
if (!TryParseUnsigned(flag, arg, value, &endp,
flag->size_t_variable())) {
return_code = j;
}
break;
case Flag::TYPE_STRING:
flag->set_string_value(value ? StrDup(value) : nullptr, true);
break;
}
// handle errors
bool is_bool_type = flag->type() == Flag::TYPE_BOOL ||
flag->type() == Flag::TYPE_MAYBE_BOOL;
if ((is_bool_type && value != nullptr) || (!is_bool_type && negated) ||
*endp != '\0') {
// TODO(neis): TryParseUnsigned may return with {*endp == '\0'} even in
// an error case.
PrintF(stderr, "Error: illegal value for flag %s of type %s\n", arg,
Type2String(flag->type()));
if (is_bool_type) {
PrintF(stderr,
"To set or unset a boolean flag, use --flag or --no-flag.\n");
}
return_code = j;
break;
}
// remove the flag & value from the command
if (remove_flags) {
while (j < i) {
argv[j++] = nullptr;
}
}
}
}
if (FLAG_help) {
PrintHelp();
exit(0);
}
if (remove_flags) {
// shrink the argument list
int j = 1;
for (int i = 1; i < *argc; i++) {
if (argv[i] != nullptr) argv[j++] = argv[i];
}
*argc = j;
} else if (return_code != 0) {
if (return_code + 1 < *argc) {
PrintF(stderr, "The remaining arguments were ignored:");
for (int i = return_code + 1; i < *argc; ++i) {
PrintF(stderr, " %s", argv[i]);
}
PrintF(stderr, "\n");
}
}
if (return_code != 0) PrintF(stderr, "Try --help for options\n");
return return_code;
}
static char* SkipWhiteSpace(char* p) {
while (*p != '\0' && isspace(*p) != 0) p++;
return p;
}
static char* SkipBlackSpace(char* p) {
while (*p != '\0' && isspace(*p) == 0) p++;
return p;
}
// static
int FlagList::SetFlagsFromString(const char* str, size_t len) {
// make a 0-terminated copy of str
std::unique_ptr<char[]> copy0{NewArray<char>(len + 1)};
MemCopy(copy0.get(), str, len);
copy0[len] = '\0';
// strip leading white space
char* copy = SkipWhiteSpace(copy0.get());
// count the number of 'arguments'
int argc = 1; // be compatible with SetFlagsFromCommandLine()
for (char* p = copy; *p != '\0'; argc++) {
p = SkipBlackSpace(p);
p = SkipWhiteSpace(p);
}
// allocate argument array
ScopedVector<char*> argv(argc);
// split the flags string into arguments
argc = 1; // be compatible with SetFlagsFromCommandLine()
for (char* p = copy; *p != '\0'; argc++) {
argv[argc] = p;
p = SkipBlackSpace(p);
if (*p != '\0') *p++ = '\0'; // 0-terminate argument
p = SkipWhiteSpace(p);
}
return SetFlagsFromCommandLine(&argc, argv.begin(), false);
}
// static
void FlagList::ResetAllFlags() {
for (size_t i = 0; i < num_flags; ++i) {
flags[i].Reset();
}
}
// static
void FlagList::PrintHelp() {
CpuFeatures::Probe(false);
CpuFeatures::PrintTarget();
CpuFeatures::PrintFeatures();
StdoutStream os;
os << "Synopsis:\n"
" shell [options] [--shell] [<file>...]\n"
" d8 [options] [-e <string>] [--shell] [[--module] <file>...]\n\n"
" -e execute a string in V8\n"
" --shell run an interactive JavaScript shell\n"
" --module execute a file as a JavaScript module\n\n"
"Note: the --module option is implicitly enabled for *.mjs files.\n\n"
"The following syntax for options is accepted (both '-' and '--' are "
"ok):\n"
" --flag (bool flags only)\n"
" --no-flag (bool flags only)\n"
" --flag=value (non-bool flags only, no spaces around '=')\n"
" --flag value (non-bool flags only)\n"
" -- (captures all remaining args in JavaScript)\n\n"
"Options:\n";
for (const Flag& f : flags) {
os << " --";
for (const char* c = f.name(); *c != '\0'; ++c) {
os << NormalizeChar(*c);
}
os << " (" << f.comment() << ")\n"
<< " type: " << Type2String(f.type()) << " default: " << f
<< "\n";
}
}
static uint32_t flag_hash = 0;
void ComputeFlagListHash() {
std::ostringstream modified_args_as_string;
#ifdef DEBUG
modified_args_as_string << "debug";
#endif // DEBUG
if (FLAG_embedded_builtins) {
modified_args_as_string << "embedded";
}
for (size_t i = 0; i < num_flags; ++i) {
Flag* current = &flags[i];
if (current->type() == Flag::TYPE_BOOL &&
current->bool_variable() == &FLAG_profile_deserialization) {
// We want to be able to flip --profile-deserialization without
// causing the code cache to get invalidated by this hash.
continue;
}
if (!current->IsDefault()) {
modified_args_as_string << i;
modified_args_as_string << *current;
}
}
std::string args(modified_args_as_string.str());
flag_hash = static_cast<uint32_t>(
base::hash_range(args.c_str(), args.c_str() + args.length()));
}
// static
void FlagList::EnforceFlagImplications() {
#define FLAG_MODE_DEFINE_IMPLICATIONS
#include "src/flag-definitions.h" // NOLINT(build/include)
#undef FLAG_MODE_DEFINE_IMPLICATIONS
ComputeFlagListHash();
}
uint32_t FlagList::Hash() { return flag_hash; }
} // namespace internal
} // namespace v8