Auto merge of #28152 - llogiq:master, r=Manishearth

This changes a lot of `.to_string()` to `.to_owned()`, removes a few redundant closures, and changes some `match`es to `if let`s.

I'm currently in the process of trying out clippy and acting on its suggestions. I started with compiletest, because we use it to test clippy, too. If this finds positive reception, I may continue refactoring other parts of the rust codebase.

Author: bors

src/compiletest/compiletest.rs

@@ -178,7 +178,7 @@ pub fn log_config(config: &Config) {
     logv(c, format!("filter: {}",
                     opt_str(&config.filter
                                    .as_ref()
-                                   .map(|re| re.to_string()))));
+                                   .map(|re| re.to_owned()))));
     logv(c, format!("runtool: {}", opt_str(&config.runtool)));
     logv(c, format!("host-rustcflags: {}",
                     opt_str(&config.host_rustcflags)));
@@ -205,19 +205,16 @@ pub fn opt_str<'a>(maybestr: &'a Option<String>) -> &'a str {
 
 pub fn opt_str2(maybestr: Option<String>) -> String {
     match maybestr {
-        None => "(none)".to_string(),
+        None => "(none)".to_owned(),
         Some(s) => s,
     }
 }
 
 pub fn run_tests(config: &Config) {
     if config.target.contains("android") {
-        match config.mode {
-            DebugInfoGdb => {
-                println!("{} debug-info test uses tcp 5039 port.\
-                         please reserve it", config.target);
-            }
-            _ =>{}
+        if let DebugInfoGdb = config.mode {
+            println!("{} debug-info test uses tcp 5039 port.\
+                     please reserve it", config.target);
         }
 
         // android debug-info test uses remote debugger
@@ -289,10 +286,10 @@ pub fn is_test(config: &Config, testfile: &Path) -> bool {
     // Pretty-printer does not work with .rc files yet
     let valid_extensions =
         match config.mode {
-          Pretty => vec!(".rs".to_string()),
-          _ => vec!(".rc".to_string(), ".rs".to_string())
+          Pretty => vec!(".rs".to_owned()),
+          _ => vec!(".rc".to_owned(), ".rs".to_owned())
         };
-    let invalid_prefixes = vec!(".".to_string(), "#".to_string(), "~".to_string());
+    let invalid_prefixes = vec!(".".to_owned(), "#".to_owned(), "~".to_owned());
     let name = testfile.file_name().unwrap().to_str().unwrap();
 
     let mut valid = false;
@@ -364,7 +361,7 @@ fn extract_gdb_version(full_version_line: Option<String>) -> Option<String> {
                    full_version_line.char_at(pos + 3).is_digit(10) {
                     continue
                 }
-                return Some(full_version_line[pos..pos+3].to_string());
+                return Some(full_version_line[pos..pos+3].to_owned());
             }
             println!("Could not extract GDB version from line '{}'",
                      full_version_line);
@@ -386,9 +383,8 @@ fn extract_lldb_version(full_version_line: Option<String>) -> Option<String> {
     // We are only interested in the major version number, so this function
     // will return `Some("179")` and `Some("300")` respectively.
 
-    match full_version_line {
-        Some(ref full_version_line)
-          if !full_version_line.trim().is_empty() => {
+    if let Some(ref full_version_line) = full_version_line {
+        if !full_version_line.trim().is_empty() {
             let full_version_line = full_version_line.trim();
 
             for (pos, l) in full_version_line.char_indices() {
@@ -410,8 +406,7 @@ fn extract_lldb_version(full_version_line: Option<String>) -> Option<String> {
             }
             println!("Could not extract LLDB version from line '{}'",
                      full_version_line);
-            None
-        },
-        _ => None
+        }
     }
+    None
 }

src/compiletest/errors.rs

@@ -76,7 +76,7 @@ fn parse_expected(last_nonfollow_error: Option<usize>,
     let letters = line[kind_start..].chars();
     let msg = letters.skip_while(|c| c.is_whitespace())
                      .skip_while(|c| !c.is_whitespace())
-                     .collect::<String>().trim().to_string();
+                     .collect::<String>().trim().to_owned();
 
     let (which, line) = if follow {
         assert!(adjusts == 0, "use either //~| or //~^, not both.");

src/compiletest/header.rs

@@ -67,10 +67,9 @@ pub fn load_props(testfile: &Path) -> TestProps {
     let mut pretty_compare_only = false;
     let mut forbid_output = Vec::new();
     iter_header(testfile, &mut |ln| {
-        match parse_error_pattern(ln) {
-          Some(ep) => error_patterns.push(ep),
-          None => ()
-        };
+        if let Some(ep) = parse_error_pattern(ln) {
+           error_patterns.push(ep);
+        }
 
         if compile_flags.is_none() {
             compile_flags = parse_compile_flags(ln);
@@ -108,24 +107,20 @@ pub fn load_props(testfile: &Path) -> TestProps {
             pretty_compare_only = parse_pretty_compare_only(ln);
         }
 
-        match parse_aux_build(ln) {
-            Some(ab) => { aux_builds.push(ab); }
-            None => {}
+        if let  Some(ab) = parse_aux_build(ln) {
+            aux_builds.push(ab);
         }
 
-        match parse_exec_env(ln) {
-            Some(ee) => { exec_env.push(ee); }
-            None => {}
+        if let Some(ee) = parse_exec_env(ln) {
+            exec_env.push(ee);
         }
 
-        match parse_check_line(ln) {
-            Some(cl) => check_lines.push(cl),
-            None => ()
-        };
+        if let Some(cl) =  parse_check_line(ln) {
+            check_lines.push(cl);
+        }
 
-        match parse_forbid_output(ln) {
-            Some(of) => forbid_output.push(of),
-            None => (),
+        if let Some(of) = parse_forbid_output(ln) {
+            forbid_output.push(of);
         }
 
         true
@@ -134,8 +129,8 @@ pub fn load_props(testfile: &Path) -> TestProps {
     for key in vec!["RUST_TEST_NOCAPTURE", "RUST_TEST_THREADS"] {
         match env::var(key) {
             Ok(val) =>
-                if exec_env.iter().find(|&&(ref x, _)| *x == key.to_string()).is_none() {
-                    exec_env.push((key.to_string(), val))
+                if exec_env.iter().find(|&&(ref x, _)| *x == key).is_none() {
+                    exec_env.push((key.to_owned(), val))
                 },
             Err(..) => {}
         }
@@ -153,7 +148,7 @@ pub fn load_props(testfile: &Path) -> TestProps {
         check_stdout: check_stdout,
         no_prefer_dynamic: no_prefer_dynamic,
         pretty_expanded: pretty_expanded,
-        pretty_mode: pretty_mode.unwrap_or("normal".to_string()),
+        pretty_mode: pretty_mode.unwrap_or("normal".to_owned()),
         pretty_compare_only: pretty_compare_only,
         forbid_output: forbid_output,
     }
@@ -182,22 +177,21 @@ pub fn is_test_ignored(config: &Config, testfile: &Path) -> bool {
             return true;
         }
 
-        match config.gdb_version {
-            Some(ref actual_version) => {
-                if line.contains("min-gdb-version") {
-                    let min_version = line.trim()
-                                          .split(' ')
-                                          .last()
-                                          .expect("Malformed GDB version directive");
-                    // Ignore if actual version is smaller the minimum required
-                    // version
-                    gdb_version_to_int(actual_version) <
-                        gdb_version_to_int(min_version)
-                } else {
-                    false
-                }
+        if let Some(ref actual_version) = config.gdb_version {
+            if line.contains("min-gdb-version") {
+                let min_version = line.trim()
+                                      .split(' ')
+                                      .last()
+                                      .expect("Malformed GDB version directive");
+                // Ignore if actual version is smaller the minimum required
+                // version
+                gdb_version_to_int(actual_version) <
+                    gdb_version_to_int(min_version)
+            } else {
+                false
             }
-            None => false
+        } else {
+            false
         }
     }
 
@@ -210,22 +204,21 @@ pub fn is_test_ignored(config: &Config, testfile: &Path) -> bool {
             return true;
         }
 
-        match config.lldb_version {
-            Some(ref actual_version) => {
-                if line.contains("min-lldb-version") {
-                    let min_version = line.trim()
-                                          .split(' ')
-                                          .last()
-                                          .expect("Malformed lldb version directive");
-                    // Ignore if actual version is smaller the minimum required
-                    // version
-                    lldb_version_to_int(actual_version) <
-                        lldb_version_to_int(min_version)
-                } else {
-                    false
-                }
+        if let Some(ref actual_version) = config.lldb_version {
+            if line.contains("min-lldb-version") {
+                let min_version = line.trim()
+                                      .split(' ')
+                                      .last()
+                                      .expect("Malformed lldb version directive");
+                // Ignore if actual version is smaller the minimum required
+                // version
+                lldb_version_to_int(actual_version) <
+                    lldb_version_to_int(min_version)
+            } else {
+                false
             }
-            None => false
+        } else {
+            false
         }
     }
 
@@ -316,11 +309,11 @@ fn parse_exec_env(line: &str) -> Option<(String, String)> {
         // nv is either FOO or FOO=BAR
         let mut strs: Vec<String> = nv
                                       .splitn(2, '=')
-                                      .map(|s| s.to_string())
+                                      .map(str::to_owned)
                                       .collect();
 
         match strs.len() {
-          1 => (strs.pop().unwrap(), "".to_string()),
+          1 => (strs.pop().unwrap(), "".to_owned()),
           2 => {
               let end = strs.pop().unwrap();
               (strs.pop().unwrap(), end)
@@ -331,33 +324,31 @@ fn parse_exec_env(line: &str) -> Option<(String, String)> {
 }
 
 fn parse_pp_exact(line: &str, testfile: &Path) -> Option<PathBuf> {
-    match parse_name_value_directive(line, "pp-exact") {
-      Some(s) => Some(PathBuf::from(&s)),
-      None => {
+    if let Some(s) = parse_name_value_directive(line, "pp-exact") {
+        Some(PathBuf::from(&s))
+    } else {
         if parse_name_directive(line, "pp-exact") {
-            testfile.file_name().map(|s| PathBuf::from(s))
+            testfile.file_name().map(PathBuf::from)
         } else {
             None
         }
-      }
     }
 }
 
 fn parse_name_directive(line: &str, directive: &str) -> bool {
     // This 'no-' rule is a quick hack to allow pretty-expanded and no-pretty-expanded to coexist
-    line.contains(directive) && !line.contains(&("no-".to_string() + directive))
+    line.contains(directive) && !line.contains(&("no-".to_owned() + directive))
 }
 
 pub fn parse_name_value_directive(line: &str, directive: &str)
                                   -> Option<String> {
     let keycolon = format!("{}:", directive);
-    match line.find(&keycolon) {
-        Some(colon) => {
-            let value = line[(colon + keycolon.len()) .. line.len()].to_string();
-            debug!("{}: {}", directive, value);
-            Some(value)
-        }
-        None => None
+    if let Some(colon) = line.find(&keycolon) {
+        let value = line[(colon + keycolon.len()) .. line.len()].to_owned();
+        debug!("{}: {}", directive, value);
+        Some(value)
+    } else {
+        None
     }
 }
 

src/compiletest/procsrv.rs

@@ -17,9 +17,8 @@ fn add_target_env(cmd: &mut Command, lib_path: &str, aux_path: Option<&str>) {
     // Need to be sure to put both the lib_path and the aux path in the dylib
     // search path for the child.
     let mut path = DynamicLibrary::search_path();
-    match aux_path {
-        Some(p) => path.insert(0, PathBuf::from(p)),
-        None => {}
+    if let Some(p) = aux_path {
+        path.insert(0, PathBuf::from(p))
     }
     path.insert(0, PathBuf::from(lib_path));