Adopt env_scoped_t::snapshot() and remove env_var_snapshot_t

Remove the env_var_snapshot_t class and switch everything to the new snapshot
function of env_scoped_t.

Fixes #5658. Fixes #5571.

src/env.cpp

@@ -181,7 +181,6 @@ wcstring environment_t::get_pwd_slash() const {
     return pwd;
 }
 
-null_environment_t::null_environment_t() = default;
 null_environment_t::~null_environment_t() = default;
 maybe_t<env_var_t> null_environment_t::get(const wcstring &key, env_mode_flags_t mode) const {
     UNUSED(key);
@@ -1140,39 +1139,6 @@ env_stack_t &env_stack_t::globals() {
     return s_global;
 }
 
-env_vars_snapshot_t::env_vars_snapshot_t(const environment_t &source, const wchar_t *const *keys) {
-    ASSERT_IS_MAIN_THREAD();
-    wcstring key;
-    for (size_t i = 0; keys[i]; i++) {
-        key.assign(keys[i]);
-        const auto var = source.get(key);
-        if (var) {
-            vars[key] = std::move(*var);
-        }
-    }
-    names = source.get_names(0);
-}
-
-env_vars_snapshot_t::~env_vars_snapshot_t() = default;
-
-maybe_t<env_var_t> env_vars_snapshot_t::get(const wcstring &key, env_mode_flags_t mode) const {
-    UNUSED(mode);
-    auto iter = vars.find(key);
-    if (iter == vars.end()) return none();
-    return iter->second;
-}
-
-wcstring_list_t env_vars_snapshot_t::get_names(int flags) const {
-    UNUSED(flags);
-    return names;
-}
-
-const wchar_t *const env_vars_snapshot_t::highlighting_keys[] = {
-    L"PATH", L"CDPATH", L"fish_function_path", L"PWD", L"HOME", NULL};
-
-const wchar_t *const env_vars_snapshot_t::completing_keys[] = {
-    L"PATH", L"CDPATH", L"fish_function_path", L"PWD", L"HOME", NULL};
-
 #if defined(__APPLE__) || defined(__CYGWIN__)
 static int check_runtime_path(const char *path) {
     UNUSED(path);

src/env.h

@@ -186,7 +186,7 @@ class environment_t {
 /// The null environment contains nothing.
 class null_environment_t : public environment_t {
    public:
-    null_environment_t();
+    null_environment_t() = default;
     ~null_environment_t() override;
 
     maybe_t<env_var_t> get(const wcstring &key, env_mode_flags_t mode = ENV_DEFAULT) const override;
@@ -296,28 +296,6 @@ class env_stack_t final : public env_scoped_t {
     static env_stack_t &globals();
 };
 
-class env_vars_snapshot_t : public environment_t {
-    std::map<wcstring, env_var_t> vars;
-    wcstring_list_t names;
-
-   public:
-    env_vars_snapshot_t() = default;
-    env_vars_snapshot_t(const env_vars_snapshot_t &) = default;
-    env_vars_snapshot_t &operator=(const env_vars_snapshot_t &) = default;
-    env_vars_snapshot_t(const environment_t &source, const wchar_t *const *keys);
-    ~env_vars_snapshot_t() override;
-
-    maybe_t<env_var_t> get(const wcstring &key, env_mode_flags_t mode = ENV_DEFAULT) const override;
-
-    wcstring_list_t get_names(int flags) const override;
-
-    // Vars necessary for highlighting.
-    static const wchar_t *const highlighting_keys[];
-
-    // Vars necessary for completion.
-    static const wchar_t *const completing_keys[];
-};
-
 extern int g_fork_count;
 extern bool g_use_posix_spawn;
 

src/fish_tests.cpp

@@ -2914,7 +2914,7 @@ static void test_autosuggest_suggest_special() {
 
 static void perform_one_autosuggestion_should_ignore_test(const wcstring &command, long line) {
     completion_list_t comps;
-    complete(command, &comps, COMPLETION_REQUEST_AUTOSUGGESTION, env_vars_snapshot_t{});
+    complete(command, &comps, COMPLETION_REQUEST_AUTOSUGGESTION, null_environment_t{});
     do_test(comps.empty());
     if (!comps.empty()) {
         const wcstring &suggestion = comps.front().completion;

src/reader.cpp

@@ -1276,10 +1276,9 @@ void reader_data_t::completion_insert(const wchar_t *val, complete_flags_t flags
 // on a background thread) to determine the autosuggestion
 static std::function<autosuggestion_result_t(void)> get_autosuggestion_performer(
     const wcstring &search_string, size_t cursor_pos, history_t *history) {
-    const auto &parser_vars = parser_t::principal_parser().vars();
     const unsigned int generation_count = read_generation_count();
-    const wcstring working_directory = parser_vars.get_pwd_slash();
+    auto vars = parser_t::principal_parser().vars().snapshot();
-    env_vars_snapshot_t vars(parser_vars, env_vars_snapshot_t::completing_keys);
+    const wcstring working_directory = vars->get_pwd_slash();
     // TODO: suspicious use of 'history' here
     // This is safe because histories are immortal, but perhaps
     // this should use shared_ptr
@@ -1306,7 +1305,7 @@ static std::function<autosuggestion_result_t(void)> get_autosuggestion_performer
             // Skip items with newlines because they make terrible autosuggestions.
             if (item.str().find('\n') != wcstring::npos) continue;
 
-            if (autosuggest_validate_from_history(item, working_directory, vars)) {
+            if (autosuggest_validate_from_history(item, working_directory, *vars)) {
                 // The command autosuggestion was handled specially, so we're done.
                 return {searcher.current_string(), search_string};
             }
@@ -1328,7 +1327,7 @@ static std::function<autosuggestion_result_t(void)> get_autosuggestion_performer
         // Try normal completions.
         completion_request_flags_t complete_flags = COMPLETION_REQUEST_AUTOSUGGESTION;
         std::vector<completion_t> completions;
-        complete(search_string, &completions, complete_flags, vars);
+        complete(search_string, &completions, complete_flags, *vars);
         completions_sort_and_prioritize(&completions, complete_flags);
         if (!completions.empty()) {
             const completion_t &comp = completions.at(0);
@@ -2041,8 +2040,7 @@ void reader_data_t::highlight_complete(highlight_result_t result) {
 // return a function that performs highlighting. The function may be invoked on a background thread.
 static std::function<highlight_result_t(void)> get_highlight_performer(
     const wcstring &text, long match_highlight_pos, highlight_function_t highlight_func) {
-    env_vars_snapshot_t vars(parser_t::principal_parser().vars(),
+    auto vars = parser_t::principal_parser().vars().snapshot();
-                             env_vars_snapshot_t::highlighting_keys);
     unsigned int generation_count = read_generation_count();
     return [=]() -> highlight_result_t {
         if (text.empty()) return {};
@@ -2052,7 +2050,7 @@ static std::function<highlight_result_t(void)> get_highlight_performer(
         }
         s_thread_generation = generation_count;
         std::vector<highlight_spec_t> colors(text.size(), highlight_spec_t{});
-        highlight_func(text, colors, match_highlight_pos, NULL /* error */, vars);
+        highlight_func(text, colors, match_highlight_pos, NULL /* error */, *vars);
         return {std::move(colors), text};
     };
 }