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Cleanup and simplify null_terminated_array_t and its clients

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This commit is contained in:
ridiculousfish 2013-02-22 16:22:56 -08:00
parent d99c2cb9a7
commit a8e92639af
7 changed files with 113 additions and 121 deletions
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75
common.cpp
View File

@ -1978,18 +1978,21 @@ void exit_without_destructors(int code)
}
/* Helper function to convert from a null_terminated_array_t<wchar_t> to a null_terminated_array_t<char_t> */
null_terminated_array_t<char> convert_wide_array_to_narrow(const null_terminated_array_t<wchar_t> &wide_arr)
void convert_wide_array_to_narrow(const null_terminated_array_t<wchar_t> &wide_arr, null_terminated_array_t<char> *output)
{
const wchar_t *const *arr = wide_arr.get();
if (! arr)
return null_terminated_array_t<char>();
{
output->clear();
return;
}
std::vector<std::string> list;
for (size_t i=0; arr[i]; i++)
{
list.push_back(wcs2string(arr[i]));
}
return null_terminated_array_t<char>(list);
output->set(list);
}
void append_path_component(wcstring &path, const wcstring &component)
@ -2167,3 +2170,69 @@ wcstokenizer::~wcstokenizer()
{
free(buffer);
}
template <typename CharType_t>
static CharType_t **make_null_terminated_array_helper(const std::vector<std::basic_string<CharType_t> > &argv)
{
size_t count = argv.size();
/* We allocate everything in one giant block. First compute how much space we need. */
/* N + 1 pointers */
size_t pointers_allocation_len = (count + 1) * sizeof(CharType_t *);
/* In the very unlikely event that CharType_t has stricter alignment requirements than does a pointer, round us up to the size of a CharType_t */
pointers_allocation_len += sizeof(CharType_t) - 1;
pointers_allocation_len -= pointers_allocation_len % sizeof(CharType_t);
/* N null terminated strings */
size_t strings_allocation_len = 0;
for (size_t i=0; i < count; i++)
{
/* The size of the string, plus a null terminator */
strings_allocation_len += (argv.at(i).size() + 1) * sizeof(CharType_t);
}
/* Now allocate their sum */
unsigned char *base = static_cast<unsigned char *>(malloc(pointers_allocation_len + strings_allocation_len));
if (! base) return NULL;
/* Divvy it up into the pointers and strings */
CharType_t **pointers = reinterpret_cast<CharType_t **>(base);
CharType_t *strings = reinterpret_cast<CharType_t *>(base + pointers_allocation_len);
/* Start copying */
for (size_t i=0; i < count; i++)
{
const std::basic_string<CharType_t> &str = argv.at(i);
// store the current string pointer into self
*pointers++ = strings;
// copy the string into strings
strings = std::copy(str.begin(), str.end(), strings);
// each string needs a null terminator
*strings++ = (CharType_t)(0);
}
// array of pointers needs a null terminator
*pointers++ = NULL;
// Make sure we know what we're doing
assert((unsigned char *)pointers - base == (ptrdiff_t)pointers_allocation_len);
assert((unsigned char *)strings - (unsigned char *)pointers == (ptrdiff_t)strings_allocation_len);
assert((unsigned char *)strings - base == (ptrdiff_t)(pointers_allocation_len + strings_allocation_len));
// Return what we did
return reinterpret_cast<CharType_t**>(base);
}
wchar_t **make_null_terminated_array(const wcstring_list_t &lst)
{
return make_null_terminated_array_helper(lst);
}
char **make_null_terminated_array(const std::vector<std::string> &lst)
{
return make_null_terminated_array_helper(lst);
}

120
common.h
View File

@ -330,140 +330,70 @@ inline wcstring to_string(const int &x)
return to_string(static_cast<long>(x));
}
wchar_t **make_null_terminated_array(const wcstring_list_t &lst);
char **make_null_terminated_array(const std::vector<std::string> &lst);
/* Helper class for managing a null-terminated array of null-terminated strings (of some char type) */
template <typename CharType_t>
class null_terminated_array_t
{
CharType_t **array;
/* No assignment or copying */
void operator=(null_terminated_array_t rhs);
null_terminated_array_t(const null_terminated_array_t &);
typedef std::basic_string<CharType_t> string_t;
typedef std::vector<string_t> string_list_t;
void swap(null_terminated_array_t<CharType_t> &him)
{
std::swap(array, him.array);
}
/* Silly function to get the length of a null terminated array of...something */
template <typename T>
static size_t count_not_null(const T *arr)
{
size_t len;
for (len=0; arr[len] != T(0); len++)
;
return len;
}
typedef std::vector<std::basic_string<CharType_t> > string_list_t;
size_t size() const
{
return count_not_null(array);
size_t len = 0;
if (array != NULL)
{
while (array[len] != NULL)
{
len++;
}
}
return len;
}
void free(void)
{
if (array != NULL)
{
for (size_t i = 0; array[i] != NULL; i++)
{
delete [] array[i];
}
delete [] array;
array = NULL;
}
::free((void *)array);
array = NULL;
}
public:
null_terminated_array_t() : array(NULL) { }
null_terminated_array_t(const string_list_t &argv) : array(NULL)
null_terminated_array_t(const string_list_t &argv) : array(make_null_terminated_array(argv))
{
this->set(argv);
}
~null_terminated_array_t()
{
this->free();
}
/** operator=. Notice the pass-by-value parameter. */
null_terminated_array_t& operator=(null_terminated_array_t rhs)
{
if (this != &rhs)
this->swap(rhs);
return *this;
}
/* Copy constructor. */
null_terminated_array_t(const null_terminated_array_t &him) : array(NULL)
{
this->set(him.array);
}
void set(const string_list_t &argv)
{
/* Get rid of the old argv */
this->free();
/* Allocate our null-terminated array of null-terminated strings */
size_t i, count = argv.size();
this->array = new CharType_t * [count + 1];
for (i=0; i < count; i++)
{
const string_t &str = argv.at(i);
this->array[i] = new CharType_t [1 + str.size()];
std::copy(str.begin(), str.end(), this->array[i]);
this->array[i][str.size()] = CharType_t(0);
}
this->array[count] = NULL;
this->array = make_null_terminated_array(argv);
}
void set(const CharType_t * const *new_array)
{
if (new_array == array)
return;
/* Get rid of the old argv */
this->free();
/* Copy the new one */
if (new_array)
{
size_t i, count = count_not_null(new_array);
this->array = new CharType_t * [count + 1];
for (i=0; i < count; i++)
{
size_t len = count_not_null(new_array[i]);
this->array[i] = new CharType_t [1 + len];
std::copy(new_array[i], new_array[i] + len, this->array[i]);
this->array[i][len] = CharType_t(0);
}
this->array[count] = NULL;
}
}
CharType_t **get()
{
return array;
}
const CharType_t * const *get() const
{
return array;
}
string_list_t to_list() const
void clear()
{
string_list_t lst;
if (array != NULL)
{
size_t count = this->size();
lst.reserve(count);
lst.insert(lst.end(), array, array + count);
}
return lst;
this->free();
}
};
/* Helper function to convert from a null_terminated_array_t<wchar_t> to a null_terminated_array_t<char_t> */
null_terminated_array_t<char> convert_wide_array_to_narrow(const null_terminated_array_t<wchar_t> &arr);
void convert_wide_array_to_narrow(const null_terminated_array_t<wchar_t> &arr, null_terminated_array_t<char> *output);
/* Helper class to cache a narrow version of a wcstring in a malloc'd buffer, so that we can read it after fork() */
class narrow_string_rep_t

9
env.cpp
View File

@ -1478,20 +1478,13 @@ static void update_export_array_if_necessary(bool recalc)
}
char **env_export_arr(bool recalc)
const char * const *env_export_arr(bool recalc)
{
ASSERT_IS_MAIN_THREAD();
update_export_array_if_necessary(recalc);
return export_array.get();
}
void env_export_arr(bool recalc, null_terminated_array_t<char> &output)
{
ASSERT_IS_MAIN_THREAD();
update_export_array_if_necessary(recalc);
output = export_array;
}
env_vars_snapshot_t::env_vars_snapshot_t(const wchar_t * const *keys)
{
ASSERT_IS_MAIN_THREAD();

3
env.h
View File

@ -206,8 +206,7 @@ void env_push(bool new_scope);
void env_pop();
/** Returns an array containing all exported variables in a format suitable for execv. */
char **env_export_arr(bool recalc);
void env_export_arr(bool recalc, null_terminated_array_t<char> &result);
const char * const * env_export_arr(bool recalc);
/**
Returns all variable names.

21
exec.cpp
View File

@ -271,13 +271,16 @@ char *get_interpreter(const char *command, char *interpreter, size_t buff_size)
in \c p. It never returns.
*/
/* Called in a forked child! Do not allocate memory, etc. */
static void safe_launch_process(process_t *p, const char *actual_cmd, char **argv, char **envv)
static void safe_launch_process(process_t *p, const char *actual_cmd, const char *const* cargv, const char *const *cenvv)
{
int err;
// debug( 1, L"exec '%ls'", p->argv[0] );
// Wow, this wcs2str call totally allocates memory
// This function never returns, so we take certain liberties with constness
char * const * envv = const_cast<char* const *>(cenvv);
char * const * argv = const_cast<char* const *>(cargv);
execve(actual_cmd, argv, envv);
err = errno;
@ -326,7 +329,7 @@ static void launch_process_nofork(process_t *p)
ASSERT_IS_NOT_FORKED_CHILD();
char **argv = wcsv2strv(p->get_argv());
char **envv = env_export_arr(false);
const char *const *envv = env_export_arr(false);
char *actual_cmd = wcs2str(p->actual_cmd.c_str());
/* Bounce to launch_process. This never returns. */
@ -1275,13 +1278,11 @@ void exec(parser_t &parser, job_t *j)
case EXTERNAL:
{
/* Get argv and envv before we fork */
null_terminated_array_t<char> argv_array = convert_wide_array_to_narrow(p->get_argv_array());
null_terminated_array_t<char> argv_array;
convert_wide_array_to_narrow(p->get_argv_array(), &argv_array);
null_terminated_array_t<char> envv_array;
env_export_arr(false, envv_array);
char **envv = envv_array.get();
char **argv = argv_array.get();
const char * const *argv = argv_array.get();
const char * const *envv = env_export_arr(false);
std::string actual_cmd_str = wcs2string(p->actual_cmd);
const char *actual_cmd = actual_cmd_str.c_str();
@ -1309,7 +1310,7 @@ void exec(parser_t &parser, job_t *j)
if (made_it)
{
/* We successfully made the attributes and actions; actually call posix_spawn */
int spawn_ret = posix_spawn(&pid, actual_cmd, &actions, &attr, argv, envv);
int spawn_ret = posix_spawn(&pid, actual_cmd, &actions, &attr, const_cast<char * const *>(argv), const_cast<char * const *>(envv));
/* This usleep can be used to test for various race conditions (https://github.com/fish-shell/fish-shell/issues/360) */
//usleep(10000);

4
postfork.cpp
View File

@ -528,7 +528,7 @@ bool fork_actions_make_spawn_properties(posix_spawnattr_t *attr, posix_spawn_fil
}
#endif //FISH_USE_POSIX_SPAWN
void safe_report_exec_error(int err, const char *actual_cmd, char **argv, char **envv)
void safe_report_exec_error(int err, const char *actual_cmd, const char * const *argv, const char *const *envv)
{
debug_safe(0, "Failed to execute process '%s'. Reason:", actual_cmd);
@ -542,7 +542,7 @@ void safe_report_exec_error(int err, const char *actual_cmd, char **argv, char *
long arg_max = -1;
size_t sz = 0;
char **p;
const char * const *p;
for (p=argv; *p; p++)
{
sz += strlen(*p)+1;

2
postfork.h
View File

@ -69,7 +69,7 @@ pid_t execute_fork(bool wait_for_threads_to_die);
bool do_builtin_io(const char *out, size_t outlen, const char *err, size_t errlen);
/** Report an error from failing to exec or posix_spawn a command */
void safe_report_exec_error(int err, const char *actual_cmd, char **argv, char **envv);
void safe_report_exec_error(int err, const char *actual_cmd, const char * const *argv, const char * const *envv);
#if FISH_USE_POSIX_SPAWN
/* Initializes and fills in a posix_spawnattr_t; on success, the caller should destroy it via posix_spawnattr_destroy */