Auto merge of #34186 - GuillaumeGomez:err-code-check, r=alexcrichton

Implementation of #34168

r? @brson

cc @alexcrichton
cc @steveklabnik
cc @jonathandturner

I only updated `librustc_privacy/diagnostics.rs`, and I already found a case where the code doesn't throw the expected error code (E0448).

Fixes #34168.

src/librustc_privacy/diagnostics.rs

@@ -16,7 +16,7 @@
 A private trait was used on a public type parameter bound. Erroneous code
 examples:
 
-```compile_fail
+```compile_fail,E0445
 #![deny(private_in_public)]
 
 trait Foo {
@@ -46,7 +46,7 @@ pub fn foo<T: Foo> (t: T) {} // ok!
 E0446: r##"
 A private type was used in a public type signature. Erroneous code example:
 
-```compile_fail
+```compile_fail,E0446
 #![deny(private_in_public)]
 
 mod Foo {
@@ -100,7 +100,7 @@ pub enum Foo {
 Since the enum is already public, adding `pub` on one its elements is
 unnecessary. Example:
 
-```compile_fail
+```compile_fail,
 enum Foo {
     pub Bar, // not ok!
 }
@@ -119,7 +119,7 @@ pub enum Foo {
 A tuple constructor was invoked while some of its fields are private. Erroneous
 code example:
 
-```compile_fail
+```compile_fail,E0450
 mod Bar {
     pub struct Foo(isize);
 }
@@ -157,7 +157,7 @@ pub fn new(x: isize) -> Foo {
 E0451: r##"
 A struct constructor with private fields was invoked. Erroneous code example:
 
-```compile_fail
+```compile_fail,E0451
 mod Bar {
     pub struct Foo {
         pub a: isize,

src/librustdoc/html/markdown.rs

@@ -408,7 +408,7 @@ pub fn find_testable_code(doc: &str, tests: &mut ::test::Collector) {
             tests.add_test(text.to_owned(),
                            block_info.should_panic, block_info.no_run,
                            block_info.ignore, block_info.test_harness,
-                           block_info.compile_fail);
+                           block_info.compile_fail, block_info.error_codes);
         }
     }
 
@@ -454,6 +454,7 @@ struct LangString {
     rust: bool,
     test_harness: bool,
     compile_fail: bool,
+    error_codes: Vec<String>,
 }
 
 impl LangString {
@@ -465,6 +466,7 @@ fn all_false() -> LangString {
             rust: true,  // NB This used to be `notrust = false`
             test_harness: false,
             compile_fail: false,
+            error_codes: Vec::new(),
         }
     }
 
@@ -472,9 +474,14 @@ fn parse(string: &str) -> LangString {
         let mut seen_rust_tags = false;
         let mut seen_other_tags = false;
         let mut data = LangString::all_false();
-        let allow_compile_fail = match get_unstable_features_setting() {
-            UnstableFeatures::Allow | UnstableFeatures::Cheat=> true,
-            _ => false,
+        let mut allow_compile_fail = false;
+        let mut allow_error_code_check = false;
+        match get_unstable_features_setting() {
+            UnstableFeatures::Allow | UnstableFeatures::Cheat => {
+                allow_compile_fail = true;
+                allow_error_code_check = true;
+            }
+            _ => {},
         };
 
         let tokens = string.split(|c: char|
@@ -493,7 +500,15 @@ fn parse(string: &str) -> LangString {
                     data.compile_fail = true;
                     seen_rust_tags = true;
                     data.no_run = true;
-                },
+                }
+                x if allow_error_code_check && x.starts_with("E") && x.len() == 5 => {
+                    if let Ok(_) = x[1..].parse::<u32>() {
+                        data.error_codes.push(x.to_owned());
+                        seen_rust_tags = true;
+                    } else {
+                        seen_other_tags = true;
+                    }
+                }
                 _ => { seen_other_tags = true }
             }
         }
@@ -577,7 +592,7 @@ mod tests {
     fn test_lang_string_parse() {
         fn t(s: &str,
             should_panic: bool, no_run: bool, ignore: bool, rust: bool, test_harness: bool,
-            compile_fail: bool) {
+            compile_fail: bool, error_codes: Vec<String>) {
             assert_eq!(LangString::parse(s), LangString {
                 should_panic: should_panic,
                 no_run: no_run,
@@ -585,22 +600,26 @@ fn t(s: &str,
                 rust: rust,
                 test_harness: test_harness,
                 compile_fail: compile_fail,
+                error_codes: error_codes,
             })
         }
 
         // marker                | should_panic| no_run| ignore| rust | test_harness| compile_fail
-        t("",                      false,        false,  false,  true,  false,        false);
-        t("rust",                  false,        false,  false,  true,  false,        false);
-        t("sh",                    false,        false,  false,  false, false,        false);
-        t("ignore",                false,        false,  true,   true,  false,        false);
-        t("should_panic",          true,         false,  false,  true,  false,        false);
-        t("no_run",                false,        true,   false,  true,  false,        false);
-        t("test_harness",          false,        false,  false,  true,  true,         false);
-        t("compile_fail",          false,        true,   false,  true,  false,        true);
-        t("{.no_run .example}",    false,        true,   false,  true,  false,        false);
-        t("{.sh .should_panic}",   true,         false,  false,  true,  false,        false);
-        t("{.example .rust}",      false,        false,  false,  true,  false,        false);
-        t("{.test_harness .rust}", false,        false,  false,  true,  true,         false);
+        //                       | error_codes
+        t("",                      false,        false,  false,  true,  false, false, Vec::new());
+        t("rust",                  false,        false,  false,  true,  false, false, Vec::new());
+        t("sh",                    false,        false,  false,  false, false, false, Vec::new());
+        t("ignore",                false,        false,  true,   true,  false, false, Vec::new());
+        t("should_panic",          true,         false,  false,  true,  false, false, Vec::new());
+        t("no_run",                false,        true,   false,  true,  false, false, Vec::new());
+        t("test_harness",          false,        false,  false,  true,  true,  false, Vec::new());
+        t("compile_fail",          false,        true,   false,  true,  false, true,  Vec::new());
+        t("E0450",                 false,        false,  false,  true,  false, false,
+                                   vec!("E0450".to_owned()));
+        t("{.no_run .example}",    false,        true,   false,  true,  false, false, Vec::new());
+        t("{.sh .should_panic}",   true,         false,  false,  true,  false, false, Vec::new());
+        t("{.example .rust}",      false,        false,  false,  true,  false, false, Vec::new());
+        t("{.test_harness .rust}", false,        false,  false,  true,  true,  false, Vec::new());
     }
 
     #[test]

src/librustdoc/test.rs

@@ -176,7 +176,7 @@ fn scrape_test_config(krate: &::rustc::hir::Crate) -> TestOptions {
 fn runtest(test: &str, cratename: &str, cfgs: Vec<String>, libs: SearchPaths,
            externs: core::Externs,
            should_panic: bool, no_run: bool, as_test_harness: bool,
-           compile_fail: bool, opts: &TestOptions) {
+           compile_fail: bool, mut error_codes: Vec<String>, opts: &TestOptions) {
     // the test harness wants its own `main` & top level functions, so
     // never wrap the test in `fn main() { ... }`
     let test = maketest(test, Some(cratename), as_test_harness, opts);
@@ -232,7 +232,7 @@ fn drop(&mut self) {
                                                       None,
                                                       codemap.clone());
     let old = io::set_panic(box Sink(data.clone()));
-    let _bomb = Bomb(data, old.unwrap_or(box io::stdout()));
+    let _bomb = Bomb(data.clone(), old.unwrap_or(box io::stdout()));
 
     // Compile the code
     let diagnostic_handler = errors::Handler::with_emitter(true, false, box emitter);
@@ -273,13 +273,28 @@ fn drop(&mut self) {
                     } else if count == 0 && compile_fail == true {
                         panic!("test compiled while it wasn't supposed to")
                     }
+                    if count > 0 && error_codes.len() > 0 {
+                        let out = String::from_utf8(data.lock().unwrap().to_vec()).unwrap();
+                        error_codes.retain(|err| !out.contains(err));
+                    }
                 }
                 Ok(()) if compile_fail => panic!("test compiled while it wasn't supposed to"),
                 _ => {}
             }
         }
-        Err(_) if compile_fail == false => panic!("couldn't compile the test"),
-        _ => {}
+        Err(_) => {
+            if compile_fail == false {
+                panic!("couldn't compile the test");
+            }
+            if error_codes.len() > 0 {
+                let out = String::from_utf8(data.lock().unwrap().to_vec()).unwrap();
+                error_codes.retain(|err| !out.contains(err));
+            }
+        }
+    }
+
+    if error_codes.len() > 0 {
+        panic!("Some expected error codes were not found: {:?}", error_codes);
     }
 
     if no_run { return }
@@ -411,7 +426,7 @@ pub fn new(cratename: String, cfgs: Vec<String>, libs: SearchPaths, externs: cor
 
     pub fn add_test(&mut self, test: String,
                     should_panic: bool, no_run: bool, should_ignore: bool,
-                    as_test_harness: bool, compile_fail: bool) {
+                    as_test_harness: bool, compile_fail: bool, error_codes: Vec<String>) {
         let name = if self.use_headers {
             let s = self.current_header.as_ref().map(|s| &**s).unwrap_or("");
             format!("{}_{}", s, self.cnt)
@@ -442,6 +457,7 @@ pub fn add_test(&mut self, test: String,
                         no_run,
                         as_test_harness,
                         compile_fail,
+                        error_codes,
                         &opts);
             })
         });