Add an optional mode to env_get_string()

The mode restricts the scope in which the variable is searched for.

Use this new restricted scope functionality in the `set` builtin. This
fixes `set -g` to not show local shadowing variable values, and also
allows for scoped erasing of slices.
This commit is contained in:
Kevin Ballard
2014-07-12 14:40:46 -07:00
parent 2457997cd9
commit dcc043df3b
4 changed files with 97 additions and 79 deletions

145
env.cpp
View File

@@ -936,82 +936,107 @@ const wchar_t *env_var_t::c_str(void) const
return wcstring::c_str();
}
env_var_t env_get_string(const wcstring &key)
env_var_t env_get_string(const wcstring &key, int mode)
{
/* Big hack...we only allow getting the history on the main thread. Note that history_t may ask for an environment variable, so don't take the lock here (we don't need it) */
const bool is_main = is_main_thread();
if (key == L"history" && is_main)
{
env_var_t result;
const bool has_scope = mode & (ENV_LOCAL | ENV_GLOBAL | ENV_UNIVERSAL);
const bool search_local = !has_scope || (mode & ENV_LOCAL);
const bool search_global = !has_scope || (mode & ENV_GLOBAL);
const bool search_universal = !has_scope || (mode & ENV_UNIVERSAL);
history_t *history = reader_get_history();
if (! history)
const bool search_exported = (mode & ENV_EXPORT) || !(mode & ENV_UNEXPORT);
const bool search_unexported = (mode & ENV_UNEXPORT) || !(mode & ENV_EXPORT);
/* Make the assumption that electric keys can't be shadowed elsewhere, since we currently block that in env_set() */
if (is_electric(key))
{
if (!search_global) return env_var_t::missing_var();
/* Big hack...we only allow getting the history on the main thread. Note that history_t may ask for an environment variable, so don't take the lock here (we don't need it) */
if (key == L"history" && is_main_thread())
{
history = &history_t::history_with_name(L"fish");
}
if (history)
history->get_string_representation(result, ARRAY_SEP_STR);
return result;
}
else if (key == L"COLUMNS")
{
return to_string(common_get_width());
}
else if (key == L"LINES")
{
return to_string(common_get_height());
}
else if (key == L"status")
{
return to_string(proc_get_last_status());
}
else if (key == L"umask")
{
return format_string(L"0%0.3o", get_umask());
}
else
{
{
/* Lock around a local region */
scoped_lock lock(env_lock);
env_var_t result;
env_node_t *env = top;
wcstring result;
while (env != NULL)
history_t *history = reader_get_history();
if (! history)
{
const var_entry_t *entry = env->find_entry(key);
if (entry != NULL)
{
if (entry->val == ENV_NULL)
{
return env_var_t::missing_var();
}
else
{
return entry->val;
}
}
history = &history_t::history_with_name(L"fish");
}
if (history)
history->get_string_representation(result, ARRAY_SEP_STR);
return result;
}
else if (key == L"COLUMNS")
{
return to_string(common_get_width());
}
else if (key == L"LINES")
{
return to_string(common_get_height());
}
else if (key == L"status")
{
return to_string(proc_get_last_status());
}
else if (key == L"umask")
{
return format_string(L"0%0.3o", get_umask());
}
// we should never get here unless the electric var list is out of sync
}
if (search_local || search_global) {
/* Lock around a local region */
scoped_lock lock(env_lock);
env_node_t *env = search_local ? top : global_env;
wcstring result;
while (env != NULL)
{
const var_entry_t *entry = env->find_entry(key);
if (entry != NULL && (entry->exportv ? search_exported : search_unexported))
{
if (entry->val == ENV_NULL)
{
return env_var_t::missing_var();
}
else
{
return entry->val;
}
}
if (has_scope)
{
if (!search_global || env == global_env) break;
env = global_env;
}
else
{
env = env->next_scope_to_search();
}
}
}
/* Another big hack - only do a universal barrier on the main thread (since it can change variable values)
Make sure we do this outside the env_lock because it may itself call env_get_string */
if (is_main && ! get_proc_had_barrier())
{
set_proc_had_barrier(true);
env_universal_barrier();
}
if (!search_universal) return env_var_t::missing_var();
env_var_t env_var = uvars() ? uvars()->get(key) : env_var_t::missing_var();
if (env_var == ENV_NULL)
/* Another big hack - only do a universal barrier on the main thread (since it can change variable values)
Make sure we do this outside the env_lock because it may itself call env_get_string */
if (is_main_thread() && ! get_proc_had_barrier())
{
set_proc_had_barrier(true);
env_universal_barrier();
}
if (uvars())
{
env_var_t env_var = uvars()->get(key);
if (env_var == ENV_NULL || !(uvars()->get_export(key) ? search_exported : search_unexported))
{
env_var = env_var_t::missing_var();
}
return env_var;
}
return env_var_t::missing_var();
}
bool env_exist(const wchar_t *key, int mode)