[clang-tidy] Add several references

Found with performance-unnecessary-value-param

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/complete.cpp

@@ -1643,16 +1643,16 @@ void complete(const wcstring &cmd_with_subcmds, std::vector<completion_t> *out_c
 
 /// Print the short switch \c opt, and the argument \c arg to the specified
 /// wcstring, but only if \c argument isn't an empty string.
-static void append_switch(wcstring &out, wchar_t opt, const wcstring arg) {
+static void append_switch(wcstring &out, wchar_t opt, const wcstring &arg) {
     if (arg.empty()) return;
     append_format(out, L" -%lc %ls", opt, escape_string(arg, ESCAPE_ALL).c_str());
 }
-static void append_switch(wcstring &out, const wcstring opt, const wcstring arg) {
+static void append_switch(wcstring &out, const wcstring &opt, const wcstring &arg) {
     if (arg.empty()) return;
     append_format(out, L" --%ls %ls", opt.c_str(), escape_string(arg, ESCAPE_ALL).c_str());
 }
 static void append_switch(wcstring &out, wchar_t opt) { append_format(out, L" -%lc", opt); }
-static void append_switch(wcstring &out, const wcstring opt) {
+static void append_switch(wcstring &out, const wcstring &opt) {
     append_format(out, L" --%ls", opt.c_str());
 }
 

src/env.cpp

@@ -878,7 +878,7 @@ class env_stack_impl_t final : public env_scoped_impl_t {
 
     /// Remove a variable from the chain \p node.
     /// \return true if the variable was found and removed.
-    bool remove_from_chain(env_node_ref_t node, const wcstring &key) const {
+    bool remove_from_chain(const env_node_ref_t &node, const wcstring &key) const {
         for (auto cursor = node; cursor; cursor = cursor->next) {
             auto iter = cursor->env.find(key);
             if (iter != cursor->env.end()) {
@@ -901,7 +901,7 @@ class env_stack_impl_t final : public env_scoped_impl_t {
     void set_universal(const wcstring &key, wcstring_list_t val, const query_t &query);
 
     /// Set a variable in a given node \p node.
-    void set_in_node(env_node_ref_t node, const wcstring &key, wcstring_list_t &&val,
+    void set_in_node(const env_node_ref_t &node, const wcstring &key, wcstring_list_t &&val,
                      const var_flags_t &flags);
 
     // Implement the default behavior of 'set' by finding the node for an unspecified scope.
@@ -970,8 +970,8 @@ static wcstring_list_t colon_split(const wcstring_list_t &val) {
     return split_val;
 }
 
-void env_stack_impl_t::set_in_node(env_node_ref_t node, const wcstring &key, wcstring_list_t &&val,
-                                   const var_flags_t &flags) {
+void env_stack_impl_t::set_in_node(const env_node_ref_t &node, const wcstring &key,
+                                   wcstring_list_t &&val, const var_flags_t &flags) {
     env_var_t &var = node->env[key];
 
     // Use an explicit exports, or inherit from the existing variable.

src/env_universal_common.cpp

@@ -277,7 +277,7 @@ void env_universal_t::set_internal(const wcstring &key, const env_var_t &var) {
     }
 }
 
-void env_universal_t::set(const wcstring &key, env_var_t var) {
+void env_universal_t::set(const wcstring &key, const env_var_t &var) {
     scoped_lock locker(lock);
     this->set_internal(key, var);
 }

src/env_universal_common.h

@@ -103,7 +103,7 @@ class env_universal_t {
     maybe_t<env_var_t::env_var_flags_t> get_flags(const wcstring &name) const;
 
     // Sets a variable.
-    void set(const wcstring &key, env_var_t var);
+    void set(const wcstring &key, const env_var_t &var);
 
     // Removes a variable. Returns true if it was found, false if not.
     bool remove(const wcstring &key);

src/exec.cpp

@@ -241,7 +241,7 @@ static void on_process_created(const std::shared_ptr<job_t> &j, pid_t child_pid)
 /// (stdout), and there is a dup2 3->1, then we need to write to fd 3. Then exit the internal
 /// process.
 static bool run_internal_process(process_t *p, std::string outdata, std::string errdata,
-                                 io_chain_t ios) {
+                                 const io_chain_t &ios) {
     p->check_generations_before_launch();
 
     // We want both the dup2s and the io_chain_ts to be kept alive by the background thread, because
@@ -780,8 +780,8 @@ static proc_performer_t get_performer_for_process(process_t *p, const job_t *job
 /// \p conflicts contains the list of fds which pipes should avoid.
 /// \p allow_buffering if true, permit buffering the output.
 /// \return true on success, false on error.
-static bool exec_block_or_func_process(parser_t &parser, std::shared_ptr<job_t> j, process_t *p,
-                                       const fd_set_t &conflicts, io_chain_t io_chain,
+static bool exec_block_or_func_process(parser_t &parser, const std::shared_ptr<job_t> &j,
+                                       process_t *p, const fd_set_t &conflicts, io_chain_t io_chain,
                                        bool allow_buffering) {
     // Create an output buffer if we're piping to another process.
     shared_ptr<io_bufferfill_t> block_output_bufferfill{};
@@ -839,7 +839,7 @@ static bool exec_block_or_func_process(parser_t &parser, std::shared_ptr<job_t>
 /// \p deferred_pipes represents the pipes from our deferred process; if set ensure they get closed
 /// in any child. If \p is_deferred_run is true, then this is a deferred run; this affects how
 /// certain buffering works. \returns true on success, false on exec error.
-static bool exec_process_in_job(parser_t &parser, process_t *p, std::shared_ptr<job_t> j,
+static bool exec_process_in_job(parser_t &parser, process_t *p, const std::shared_ptr<job_t> &j,
                                 const io_chain_t &block_io, autoclose_pipes_t pipes,
                                 const fd_set_t &conflicts, const autoclose_pipes_t &deferred_pipes,
                                 size_t stdout_read_limit, bool is_deferred_run = false) {
@@ -1027,7 +1027,7 @@ static bool should_claim_process_group_for_job(const shared_ptr<job_t> &j) {
     DIE("unreachable");
 }
 
-bool exec_job(parser_t &parser, shared_ptr<job_t> j, const job_lineage_t &lineage) {
+bool exec_job(parser_t &parser, const shared_ptr<job_t> &j, const job_lineage_t &lineage) {
     assert(j && "null job_t passed to exec_job!");
 
     // Set to true if something goes wrong while executing the job, in which case the cleanup

src/exec.h

@@ -15,7 +15,7 @@
 class job_t;
 struct job_lineage_t;
 class parser_t;
-bool exec_job(parser_t &parser, std::shared_ptr<job_t> j, const job_lineage_t &lineage);
+bool exec_job(parser_t &parser, const std::shared_ptr<job_t> &j, const job_lineage_t &lineage);
 
 /// Evaluate the expression cmd in a subshell, add the outputs into the list l. On return, the
 /// status flag as returned bu \c proc_gfet_last_status will not be changed.

src/function.cpp

@@ -166,7 +166,8 @@ void function_add(wcstring name, wcstring description, function_properties_ref_t
 
     // Create and store a new function.
     auto ins = funcset->funcs.emplace(
-        std::move(name), function_info_t(props, std::move(description), filename, is_autoload));
+        std::move(name),
+        function_info_t(std::move(props), std::move(description), filename, is_autoload));
     assert(ins.second && "Function should not already be present in the table");
     (void)ins;
 }

src/input.cpp

@@ -17,6 +17,7 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "common.h"
@@ -427,9 +428,9 @@ bool inputter_t::mapping_is_match(const input_mapping_t &m) {
     return true;
 }
 
-void inputter_t::queue_ch(char_event_t ch) { event_queue_.push_back(ch); }
+void inputter_t::queue_ch(const char_event_t &ch) { event_queue_.push_back(std::move(ch)); }
 
-void inputter_t::push_front(char_event_t ch) { event_queue_.push_front(ch); }
+void inputter_t::push_front(const char_event_t &ch) { event_queue_.push_front(std::move(ch)); }
 
 /// \return the first mapping that matches, walking first over the user's mapping list, then the
 /// preset list. \return null if nothing matches.

src/input.h

@@ -57,10 +57,10 @@ class inputter_t {
 
     /// Enqueue a char event to the queue of unread characters that input_readch will return before
     /// actually reading from fd 0.
-    void queue_ch(char_event_t ch);
+    void queue_ch(const char_event_t &ch);
 
     /// Enqueue a char event to the front of the queue; this will be the next event returned.
-    void push_front(char_event_t ch);
+    void push_front(const char_event_t &ch);
 
     /// Sets the return status of the most recently executed input function.
     void function_set_status(bool status) { function_status_ = status; }

src/input_common.cpp

@@ -225,6 +225,6 @@ char_event_t input_event_queue_t::readch_timed(bool dequeue_timeouts) {
     return result;
 }
 
-void input_event_queue_t::push_back(char_event_t ch) { queue_.push_back(ch); }
+void input_event_queue_t::push_back(const char_event_t& ch) { queue_.push_back(ch); }
 
-void input_event_queue_t::push_front(char_event_t ch) { queue_.push_front(ch); }
+void input_event_queue_t::push_front(const char_event_t& ch) { queue_.push_front(ch); }

src/input_common.h

@@ -186,11 +186,11 @@ class input_event_queue_t {
 
     /// Enqueue a character or a readline function to the queue of unread characters that
     /// readch will return before actually reading from fd 0.
-    void push_back(char_event_t ch);
+    void push_back(const char_event_t& ch);
 
     /// Add a character or a readline function to the front of the queue of unread characters.  This
     /// will be the next character returned by readch.
-    void push_front(char_event_t ch);
+    void push_front(const char_event_t& ch);
 };
 
 #endif

src/parser.cpp

@@ -626,7 +626,7 @@ eval_result_t parser_t::eval(const wcstring &cmd, const io_chain_t &io,
     }
 }
 
-eval_result_t parser_t::eval(parsed_source_ref_t ps, const io_chain_t &io,
+eval_result_t parser_t::eval(const parsed_source_ref_t &ps, const io_chain_t &io,
                              enum block_type_t block_type) {
     assert(block_type == block_type_t::top || block_type == block_type_t::subst);
     if (!ps->tree.empty()) {
@@ -640,8 +640,8 @@ eval_result_t parser_t::eval(parsed_source_ref_t ps, const io_chain_t &io,
 }
 
 template <typename T>
-eval_result_t parser_t::eval_node(parsed_source_ref_t ps, tnode_t<T> node, job_lineage_t lineage,
-                                  block_type_t block_type) {
+eval_result_t parser_t::eval_node(const parsed_source_ref_t &ps, tnode_t<T> node,
+                                  job_lineage_t lineage, block_type_t block_type) {
     static_assert(
         std::is_same<T, grammar::statement>::value || std::is_same<T, grammar::job_list>::value,
         "Unexpected node type");
@@ -683,9 +683,9 @@ eval_result_t parser_t::eval_node(parsed_source_ref_t ps, tnode_t<T> node, job_l
 }
 
 // Explicit instantiations. TODO: use overloads instead?
-template eval_result_t parser_t::eval_node(parsed_source_ref_t, tnode_t<grammar::statement>,
+template eval_result_t parser_t::eval_node(const parsed_source_ref_t &, tnode_t<grammar::statement>,
                                            job_lineage_t, block_type_t);
-template eval_result_t parser_t::eval_node(parsed_source_ref_t, tnode_t<grammar::job_list>,
+template eval_result_t parser_t::eval_node(const parsed_source_ref_t &, tnode_t<grammar::job_list>,
                                            job_lineage_t, block_type_t);
 
 void parser_t::get_backtrace(const wcstring &src, const parse_error_list_t &errors,

src/parser.h

@@ -268,13 +268,13 @@ class parser_t : public std::enable_shared_from_this<parser_t> {
 
     /// Evaluate the parsed source ps.
     /// Because the source has been parsed, a syntax error is impossible.
-    eval_result_t eval(parsed_source_ref_t ps, const io_chain_t &io,
+    eval_result_t eval(const parsed_source_ref_t &ps, const io_chain_t &io,
                        block_type_t block_type = block_type_t::top);
 
     /// Evaluates a node.
     /// The node type must be grammar::statement or grammar::job_list.
     template <typename T>
-    eval_result_t eval_node(parsed_source_ref_t ps, tnode_t<T> node, job_lineage_t lineage,
+    eval_result_t eval_node(const parsed_source_ref_t &ps, tnode_t<T> node, job_lineage_t lineage,
                             block_type_t block_type = block_type_t::top);
 
     /// Evaluate line as a list of parameters, i.e. tokenize it and perform parameter expansion and

src/proc.cpp

@@ -269,7 +269,7 @@ void process_t::check_generations_before_launch() {
     gens_ = topic_monitor_t::principal().current_generations();
 }
 
-job_t::job_t(job_id_t job_id, const properties_t &props, job_lineage_t lineage)
+job_t::job_t(job_id_t job_id, const properties_t &props, const job_lineage_t &lineage)
     : properties(props),
       job_id(job_id),
       root_constructed(lineage.root_constructed ? lineage.root_constructed : this->constructed) {}

src/proc.h

@@ -320,7 +320,7 @@ class job_t {
     void operator=(const job_t &) = delete;
 
    public:
-    job_t(job_id_t job_id, const properties_t &props, job_lineage_t lineage);
+    job_t(job_id_t job_id, const properties_t &props, const job_lineage_t &lineage);
     ~job_t();
 
     /// Returns the command as a wchar_t *. */