rustc: Use static strings in a few literals

Avoid allocating extra copies of strings by using "" instead of ~"" for
the debug options list and for the `time` function. This is a small
change, but it is in a path that's always executed.

Author: blake2-ppc

src/librustc/back/link.rs

@@ -1007,9 +1007,9 @@ pub fn link_args(sess: Session,
             continue;
         }
         let dir = cratepath.dirname();
-        if dir != ~"" { args.push(~"-L" + dir); }
+        if !dir.is_empty() { args.push("-L" + dir); }
         let libarg = unlib(sess.targ_cfg, cratepath.filestem().unwrap().to_owned());
-        args.push(~"-l" + libarg);
+        args.push("-l" + libarg);
     }
 
     let ula = cstore::get_used_link_args(cstore);
@@ -1032,12 +1032,12 @@ pub fn link_args(sess: Session,
     // forces to make sure that library can be found at runtime.
 
     for path in sess.opts.addl_lib_search_paths.iter() {
-        args.push(~"-L" + path.to_str());
+        args.push("-L" + path.to_str());
     }
 
     let rustpath = filesearch::rust_path();
     for path in rustpath.iter() {
-        args.push(~"-L" + path.to_str());
+        args.push("-L" + path.to_str());
     }
 
     // The names of the extern libraries
@@ -1050,7 +1050,7 @@ pub fn link_args(sess: Session,
         // On mac we need to tell the linker to let this library
         // be rpathed
         if sess.targ_cfg.os == session::OsMacos {
-            args.push(~"-Wl,-install_name,@rpath/"
+            args.push("-Wl,-install_name,@rpath/"
                       + output.filename().unwrap());
         }
     }

src/librustc/driver/driver.rs

@@ -131,7 +131,7 @@ pub enum input {
 
 pub fn phase_1_parse_input(sess: Session, cfg: ast::CrateConfig, input: &input)
     -> ast::Crate {
-    time(sess.time_passes(), ~"parsing", (), |_| {
+    time(sess.time_passes(), "parsing", (), |_| {
         match *input {
             file_input(ref file) => {
                 parse::parse_crate_from_file(&(*file), cfg.clone(), sess.parse_sess)
@@ -167,29 +167,29 @@ pub fn phase_2_configure_and_expand(sess: Session,
     //   mod bar { macro_rules! baz!(() => {{}}) }
     //
     // baz! should not use this definition unless foo is enabled.
-    crate = time(time_passes, ~"std macros injection", crate, |crate|
+    crate = time(time_passes, "std macros injection", crate, |crate|
                  syntax::ext::expand::inject_std_macros(sess.parse_sess,
                                                         cfg.clone(),
                                                         crate));
 
-    crate = time(time_passes, ~"configuration 1", crate, |crate|
+    crate = time(time_passes, "configuration 1", crate, |crate|
                  front::config::strip_unconfigured_items(crate));
 
-    crate = time(time_passes, ~"expansion", crate, |crate|
+    crate = time(time_passes, "expansion", crate, |crate|
                  syntax::ext::expand::expand_crate(sess.parse_sess, cfg.clone(),
                                                    crate));
 
     // strip again, in case expansion added anything with a #[cfg].
-    crate = time(time_passes, ~"configuration 2", crate, |crate|
+    crate = time(time_passes, "configuration 2", crate, |crate|
                  front::config::strip_unconfigured_items(crate));
 
-    crate = time(time_passes, ~"maybe building test harness", crate, |crate|
+    crate = time(time_passes, "maybe building test harness", crate, |crate|
                  front::test::modify_for_testing(sess, crate));
 
-    crate = time(time_passes, ~"std injection", crate, |crate|
+    crate = time(time_passes, "std injection", crate, |crate|
                  front::std_inject::maybe_inject_libstd_ref(sess, crate));
 
-    crate = time(time_passes, ~"assigning node ids", crate, |crate|
+    crate = time(time_passes, "assigning node ids", crate, |crate|
                  front::assign_node_ids::assign_node_ids(sess, crate));
 
     return crate;
@@ -211,37 +211,37 @@ pub fn phase_3_run_analysis_passes(sess: Session,
 
     let time_passes = sess.time_passes();
 
-    let ast_map = time(time_passes, ~"ast indexing", (), |_|
+    let ast_map = time(time_passes, "ast indexing", (), |_|
                        syntax::ast_map::map_crate(sess.diagnostic(), crate));
 
-    time(time_passes, ~"external crate/lib resolution", (), |_|
+    time(time_passes, "external crate/lib resolution", (), |_|
          creader::read_crates(sess.diagnostic(), crate, sess.cstore,
                               sess.filesearch,
                               session::sess_os_to_meta_os(sess.targ_cfg.os),
                               sess.opts.is_static,
                               token::get_ident_interner()));
 
-    let lang_items = time(time_passes, ~"language item collection", (), |_|
+    let lang_items = time(time_passes, "language item collection", (), |_|
                           middle::lang_items::collect_language_items(crate, sess));
 
     let middle::resolve::CrateMap {
         def_map: def_map,
         exp_map2: exp_map2,
         trait_map: trait_map
     } =
-        time(time_passes, ~"resolution", (), |_|
+        time(time_passes, "resolution", (), |_|
              middle::resolve::resolve_crate(sess, lang_items, crate));
 
-    time(time_passes, ~"looking for entry point", (),
+    time(time_passes, "looking for entry point", (),
          |_| middle::entry::find_entry_point(sess, crate, ast_map));
 
-    let freevars = time(time_passes, ~"freevar finding", (), |_|
+    let freevars = time(time_passes, "freevar finding", (), |_|
                         freevars::annotate_freevars(def_map, crate));
 
-    let region_map = time(time_passes, ~"region resolution", (), |_|
+    let region_map = time(time_passes, "region resolution", (), |_|
                           middle::region::resolve_crate(sess, def_map, crate));
 
-    let rp_set = time(time_passes, ~"region parameterization inference", (), |_|
+    let rp_set = time(time_passes, "region parameterization inference", (), |_|
                       middle::region::determine_rp_in_crate(sess, ast_map, def_map, crate));
 
     let ty_cx = ty::mk_ctxt(sess, def_map, ast_map, freevars,
@@ -252,53 +252,53 @@ pub fn phase_3_run_analysis_passes(sess: Session,
         ty_cx, trait_map, crate);
 
     // These next two const passes can probably be merged
-    time(time_passes, ~"const marking", (), |_|
+    time(time_passes, "const marking", (), |_|
          middle::const_eval::process_crate(crate, ty_cx));
 
-    time(time_passes, ~"const checking", (), |_|
+    time(time_passes, "const checking", (), |_|
          middle::check_const::check_crate(sess, crate, ast_map, def_map,
                                           method_map, ty_cx));
 
     let exported_items =
-        time(time_passes, ~"privacy checking", (), |_|
+        time(time_passes, "privacy checking", (), |_|
              middle::privacy::check_crate(ty_cx, &method_map, &exp_map2, crate));
 
-    time(time_passes, ~"effect checking", (), |_|
+    time(time_passes, "effect checking", (), |_|
          middle::effect::check_crate(ty_cx, method_map, crate));
 
-    time(time_passes, ~"loop checking", (), |_|
+    time(time_passes, "loop checking", (), |_|
          middle::check_loop::check_crate(ty_cx, crate));
 
-    time(time_passes, ~"stack checking", (), |_|
+    time(time_passes, "stack checking", (), |_|
          middle::stack_check::stack_check_crate(ty_cx, crate));
 
     let middle::moves::MoveMaps {moves_map, moved_variables_set,
                                  capture_map} =
-        time(time_passes, ~"compute moves", (), |_|
+        time(time_passes, "compute moves", (), |_|
              middle::moves::compute_moves(ty_cx, method_map, crate));
 
-    time(time_passes, ~"match checking", (), |_|
+    time(time_passes, "match checking", (), |_|
          middle::check_match::check_crate(ty_cx, method_map,
                                           moves_map, crate));
 
-    time(time_passes, ~"liveness checking", (), |_|
+    time(time_passes, "liveness checking", (), |_|
          middle::liveness::check_crate(ty_cx, method_map,
                                        capture_map, crate));
 
     let (root_map, write_guard_map) =
-        time(time_passes, ~"borrow checking", (), |_|
+        time(time_passes, "borrow checking", (), |_|
              middle::borrowck::check_crate(ty_cx, method_map,
                                            moves_map, moved_variables_set,
                                            capture_map, crate));
 
-    time(time_passes, ~"kind checking", (), |_|
+    time(time_passes, "kind checking", (), |_|
          kind::check_crate(ty_cx, method_map, crate));
 
     let reachable_map =
-        time(time_passes, ~"reachability checking", (), |_|
+        time(time_passes, "reachability checking", (), |_|
              reachable::find_reachable(ty_cx, method_map, crate));
 
-    time(time_passes, ~"lint checking", (), |_|
+    time(time_passes, "lint checking", (), |_|
          lint::check_crate(ty_cx, crate));
 
     CrateAnalysis {
@@ -328,7 +328,7 @@ pub fn phase_4_translate_to_llvm(sess: Session,
                                  crate: ast::Crate,
                                  analysis: &CrateAnalysis,
                                  outputs: &OutputFilenames) -> CrateTranslation {
-    time(sess.time_passes(), ~"translation", crate, |crate|
+    time(sess.time_passes(), "translation", crate, |crate|
          trans::base::trans_crate(sess, crate, analysis,
                                   &outputs.obj_filename))
 }
@@ -349,7 +349,7 @@ pub fn phase_5_run_llvm_passes(sess: Session,
         let output_type = link::output_type_assembly;
         let asm_filename = outputs.obj_filename.with_filetype("s");
 
-        time(sess.time_passes(), ~"LLVM passes", (), |_|
+        time(sess.time_passes(), "LLVM passes", (), |_|
             link::write::run_passes(sess,
                                     trans.context,
                                     trans.module,
@@ -363,7 +363,7 @@ pub fn phase_5_run_llvm_passes(sess: Session,
             os::remove_file(&asm_filename);
         }
     } else {
-        time(sess.time_passes(), ~"LLVM passes", (), |_|
+        time(sess.time_passes(), "LLVM passes", (), |_|
             link::write::run_passes(sess,
                                     trans.context,
                                     trans.module,
@@ -377,7 +377,7 @@ pub fn phase_5_run_llvm_passes(sess: Session,
 pub fn phase_6_link_output(sess: Session,
                            trans: &CrateTranslation,
                            outputs: &OutputFilenames) {
-    time(sess.time_passes(), ~"linking", (), |_|
+    time(sess.time_passes(), "linking", (), |_|
          link::link_binary(sess,
                            &outputs.obj_filename,
                            &outputs.out_filename,
@@ -596,12 +596,12 @@ pub fn build_target_config(sopts: @session::options,
                            -> @session::config {
     let os = match get_os(sopts.target_triple) {
       Some(os) => os,
-      None => early_error(demitter, ~"unknown operating system")
+      None => early_error(demitter, "unknown operating system")
     };
     let arch = match get_arch(sopts.target_triple) {
       Some(arch) => arch,
       None => early_error(demitter,
-                          ~"unknown architecture: " + sopts.target_triple)
+                          "unknown architecture: " + sopts.target_triple)
     };
     let (int_type, uint_type) = match arch {
       abi::X86 => (ast::ty_i32, ast::ty_u32),
@@ -686,7 +686,7 @@ pub fn build_session_options(binary: @str,
         let mut this_bit = 0u;
         for tuple in debug_map.iter() {
             let (name, bit) = match *tuple { (ref a, _, b) => (a, b) };
-            if name == debug_flag { this_bit = bit; break; }
+            if *name == *debug_flag { this_bit = bit; break; }
         }
         if this_bit == 0u {
             early_error(demitter, format!("unknown debug flag: {}", *debug_flag))
@@ -726,7 +726,7 @@ pub fn build_session_options(binary: @str,
             No
         } else if matches.opt_present("O") {
             if matches.opt_present("opt-level") {
-                early_error(demitter, ~"-O and --opt-level both provided");
+                early_error(demitter, "-O and --opt-level both provided");
             }
             Default
         } else if matches.opt_present("opt-level") {
@@ -736,7 +736,7 @@ pub fn build_session_options(binary: @str,
               ~"2" => Default,
               ~"3" => Aggressive,
               _ => {
-                early_error(demitter, ~"optimization level needs to be between 0-3")
+                early_error(demitter, "optimization level needs to be between 0-3")
               }
             }
         } else { No }
@@ -1030,7 +1030,7 @@ pub fn build_output_filenames(input: &input,
     }
 }
 
-pub fn early_error(emitter: @diagnostic::Emitter, msg: ~str) -> ! {
+pub fn early_error(emitter: @diagnostic::Emitter, msg: &str) -> ! {
     emitter.emit(None, msg, diagnostic::fatal);
     fail2!();
 }

src/librustc/driver/session.rs

@@ -81,61 +81,60 @@ pub static no_vectorize_slp:        uint = 1 << 28;
 pub static no_prepopulate_passes:   uint = 1 << 29;
 pub static use_softfp:              uint = 1 << 30;
 
-pub fn debugging_opts_map() -> ~[(~str, ~str, uint)] {
-    ~[(~"verbose", ~"in general, enable more debug printouts", verbose),
-     (~"time-passes", ~"measure time of each rustc pass", time_passes),
-     (~"count-llvm-insns", ~"count where LLVM \
+pub fn debugging_opts_map() -> ~[(&'static str, &'static str, uint)] {
+    ~[("verbose", "in general, enable more debug printouts", verbose),
+     ("time-passes", "measure time of each rustc pass", time_passes),
+     ("count-llvm-insns", "count where LLVM \
                            instrs originate", count_llvm_insns),
-     (~"time-llvm-passes", ~"measure time of each LLVM pass",
+     ("time-llvm-passes", "measure time of each LLVM pass",
       time_llvm_passes),
-     (~"trans-stats", ~"gather trans statistics", trans_stats),
-     (~"asm-comments", ~"generate comments into the assembly (may change behavior)", asm_comments),
-     (~"no-verify", ~"skip LLVM verification", no_verify),
-     (~"trace", ~"emit trace logs", trace),
-     (~"coherence", ~"perform coherence checking", coherence),
-     (~"borrowck-stats", ~"gather borrowck statistics",  borrowck_stats),
-     (~"borrowck-note-pure", ~"note where purity is req'd",
+     ("trans-stats", "gather trans statistics", trans_stats),
+     ("asm-comments", "generate comments into the assembly (may change behavior)", asm_comments),
+     ("no-verify", "skip LLVM verification", no_verify),
+     ("trace", "emit trace logs", trace),
+     ("coherence", "perform coherence checking", coherence),
+     ("borrowck-stats", "gather borrowck statistics",  borrowck_stats),
+     ("borrowck-note-pure", "note where purity is req'd",
       borrowck_note_pure),
-     (~"borrowck-note-loan", ~"note where loans are req'd",
+     ("borrowck-note-loan", "note where loans are req'd",
       borrowck_note_loan),
-     (~"no-landing-pads", ~"omit landing pads for unwinding",
+     ("no-landing-pads", "omit landing pads for unwinding",
       no_landing_pads),
-     (~"debug-llvm", ~"enable debug output from LLVM", debug_llvm),
-     (~"count-type-sizes", ~"count the sizes of aggregate types",
+     ("debug-llvm", "enable debug output from LLVM", debug_llvm),
+     ("count-type-sizes", "count the sizes of aggregate types",
       count_type_sizes),
-     (~"meta-stats", ~"gather metadata statistics", meta_stats),
-     (~"no-opt", ~"do not optimize, even if -O is passed", no_opt),
-     (~"print-link-args", ~"Print the arguments passed to the linker", print_link_args),
-     (~"gc", ~"Garbage collect shared data (experimental)", gc),
-     (~"jit", ~"Execute using JIT (experimental)", jit),
-     (~"extra-debug-info", ~"Extra debugging info (experimental)",
+     ("meta-stats", "gather metadata statistics", meta_stats),
+     ("no-opt", "do not optimize, even if -O is passed", no_opt),
+     ("print-link-args", "Print the arguments passed to the linker", print_link_args),
+     ("gc", "Garbage collect shared data (experimental)", gc),
+     ("jit", "Execute using JIT (experimental)", jit),
+     ("extra-debug-info", "Extra debugging info (experimental)",
       extra_debug_info),
-     (~"debug-info", ~"Produce debug info (experimental)", debug_info),
-     (~"static", ~"Use or produce static libraries or binaries " +
-      "(experimental)", statik),
-     (~"no-debug-borrows",
-      ~"do not show where borrow checks fail",
+     ("debug-info", "Produce debug info (experimental)", debug_info),
+     ("static", "Use or produce static libraries or binaries (experimental)", statik),
+     ("no-debug-borrows",
+      "do not show where borrow checks fail",
       no_debug_borrows),
-     (~"lint-llvm",
-      ~"Run the LLVM lint pass on the pre-optimization IR",
+     ("lint-llvm",
+      "Run the LLVM lint pass on the pre-optimization IR",
       lint_llvm),
-     (~"once-fns",
-      ~"Allow 'once fn' closures to deinitialize captured variables",
+     ("once-fns",
+      "Allow 'once fn' closures to deinitialize captured variables",
       once_fns),
-     (~"print-llvm-passes",
-      ~"Prints the llvm optimization passes being run",
+     ("print-llvm-passes",
+      "Prints the llvm optimization passes being run",
       print_llvm_passes),
-     (~"no-prepopulate-passes",
-      ~"Don't pre-populate the pass managers with a list of passes, only use \
+     ("no-prepopulate-passes",
+      "Don't pre-populate the pass managers with a list of passes, only use \
         the passes from --passes",
       no_prepopulate_passes),
-     (~"no-vectorize-loops",
-      ~"Don't run the loop vectorization optimization passes",
+     ("no-vectorize-loops",
+      "Don't run the loop vectorization optimization passes",
       no_vectorize_loops),
-     (~"no-vectorize-slp",
-      ~"Don't run LLVM's SLP vectorization passes",
+     ("no-vectorize-slp",
+      "Don't run LLVM's SLP vectorization passes",
       no_vectorize_slp),
-     (~"soft-float", ~"Generate software floating point library calls", use_softfp),
+     ("soft-float", "Generate software floating point library calls", use_softfp),
     ]
 }