]> git.proxmox.com Git - rustc.git/blobdiff - src/tools/tidy/src/style.rs
New upstream version 1.68.2+dfsg1
[rustc.git] / src / tools / tidy / src / style.rs
index 6a0d530e2362a27b55d5b44f8b54928e25945e68..6a0855405ec90bb491547aa8e34a9bc6b4755e2d 100644 (file)
@@ -2,20 +2,30 @@
 //!
 //! Example checks are:
 //!
-//! * No lines over 100 characters.
-//! * No files with over 3000 lines.
+//! * No lines over 100 characters (in non-Rust files).
+//! * No files with over 3000 lines (in non-Rust files).
 //! * No tabs.
 //! * No trailing whitespace.
 //! * No CR characters.
 //! * No `TODO` or `XXX` directives.
 //! * No unexplained ` ```ignore ` or ` ```rust,ignore ` doc tests.
 //!
+//! Note that some of these rules are excluded from Rust files because we enforce rustfmt. It is
+//! preferable to be formatted rather than tidy-clean.
+//!
 //! A number of these checks can be opted-out of with various directives of the form:
 //! `// ignore-tidy-CHECK-NAME`.
+// ignore-tidy-dbg
 
+use crate::walk::{filter_dirs, walk};
+use regex::{Regex, RegexSet};
 use std::path::Path;
 
+/// Error code markdown is restricted to 80 columns because they can be
+/// displayed on the console with --example.
+const ERROR_CODE_COLS: usize = 80;
 const COLS: usize = 100;
+const GOML_COLS: usize = 120;
 
 const LINES: usize = 3000;
 
@@ -35,6 +45,31 @@ C++ code used llvm_unreachable, which triggers undefined behavior
 when executed when assertions are disabled.
 Use llvm::report_fatal_error for increased robustness.";
 
+const DOUBLE_SPACE_AFTER_DOT: &str = r"\
+Use a single space after dots in comments.";
+
+const ANNOTATIONS_TO_IGNORE: &[&str] = &[
+    "// @!has",
+    "// @has",
+    "// @matches",
+    "// CHECK",
+    "// EMIT_MIR",
+    "// compile-flags",
+    "// error-pattern",
+    "// gdb",
+    "// lldb",
+    "// cdb",
+    "// normalize-stderr-test",
+];
+
+// Intentionally written in decimal rather than hex
+const PROBLEMATIC_CONSTS: &[u32] = &[
+    184594741, 2880289470, 2881141438, 2965027518, 2976579765, 3203381950, 3405691582, 3405697037,
+    3735927486, 3735932941, 4027431614, 4276992702,
+];
+
+const INTERNAL_COMPILER_DOCS_LINE: &str = "#### This error code is internal to the compiler and will not be emitted with normal Rust code.";
+
 /// Parser states for `line_is_url`.
 #[derive(Clone, Copy, PartialEq)]
 #[allow(non_camel_case_types)]
@@ -45,38 +80,39 @@ enum LIUState {
     EXP_END,
 }
 
-/// Returns `true` if `line` appears to be a line comment containing an URL,
+/// Returns `true` if `line` appears to be a line comment containing a URL,
 /// possibly with a Markdown link label in front, and nothing else.
 /// The Markdown link label, if present, may not contain whitespace.
 /// Lines of this form are allowed to be overlength, because Markdown
 /// offers no way to split a line in the middle of a URL, and the lengths
 /// of URLs to external references are beyond our control.
-fn line_is_url(line: &str) -> bool {
+fn line_is_url(is_error_code: bool, columns: usize, line: &str) -> bool {
+    // more basic check for markdown, to avoid complexity in implementing two state machines
+    if is_error_code {
+        return line.starts_with('[') && line.contains("]:") && line.contains("http");
+    }
+
     use self::LIUState::*;
     let mut state: LIUState = EXP_COMMENT_START;
     let is_url = |w: &str| w.starts_with("http://") || w.starts_with("https://");
 
     for tok in line.split_whitespace() {
         match (state, tok) {
-            (EXP_COMMENT_START, "//") |
-            (EXP_COMMENT_START, "///") |
-            (EXP_COMMENT_START, "//!") => state = EXP_LINK_LABEL_OR_URL,
+            (EXP_COMMENT_START, "//") | (EXP_COMMENT_START, "///") | (EXP_COMMENT_START, "//!") => {
+                state = EXP_LINK_LABEL_OR_URL
+            }
 
             (EXP_LINK_LABEL_OR_URL, w)
-                if w.len() >= 4 && w.starts_with('[') && w.ends_with("]:")
-                => state = EXP_URL,
+                if w.len() >= 4 && w.starts_with('[') && w.ends_with("]:") =>
+            {
+                state = EXP_URL
+            }
 
-            (EXP_LINK_LABEL_OR_URL, w)
-                if is_url(w)
-                => state = EXP_END,
+            (EXP_LINK_LABEL_OR_URL, w) if is_url(w) => state = EXP_END,
 
-            (EXP_URL, w)
-                if is_url(w) || w.starts_with("../")
-                => state = EXP_END,
+            (EXP_URL, w) if is_url(w) || w.starts_with("../") => state = EXP_END,
 
-            (_, w)
-                if w.len() > COLS && is_url(w)
-                => state = EXP_END,
+            (_, w) if w.len() > columns && is_url(w) => state = EXP_END,
 
             (_, _) => {}
         }
@@ -85,15 +121,27 @@ fn line_is_url(line: &str) -> bool {
     state == EXP_END
 }
 
+/// Returns `true` if `line` can be ignored. This is the case when it contains
+/// an annotation that is explicitly ignored.
+fn should_ignore(line: &str) -> bool {
+    // Matches test annotations like `//~ ERROR text`.
+    // This mirrors the regex in src/tools/compiletest/src/runtest.rs, please
+    // update both if either are changed.
+    let re = Regex::new("\\s*//(\\[.*\\])?~.*").unwrap();
+    re.is_match(line) || ANNOTATIONS_TO_IGNORE.iter().any(|a| line.contains(a))
+}
+
 /// Returns `true` if `line` is allowed to be longer than the normal limit.
-/// Currently there is only one exception, for long URLs, but more
-/// may be added in the future.
-fn long_line_is_ok(line: &str) -> bool {
-    if line_is_url(line) {
-        return true;
+fn long_line_is_ok(extension: &str, is_error_code: bool, max_columns: usize, line: &str) -> bool {
+    match extension {
+        // fluent files are allowed to be any length
+        "ftl" => true,
+        // non-error code markdown is allowed to be any length
+        "md" if !is_error_code => true,
+        // HACK(Ezrashaw): there is no way to split a markdown header over multiple lines
+        "md" if line == INTERNAL_COMPILER_DOCS_LINE => true,
+        _ => line_is_url(is_error_code, max_columns, line) || should_ignore(line),
     }
-
-    false
 }
 
 enum Directive {
@@ -112,8 +160,10 @@ fn contains_ignore_directive(can_contain: bool, contents: &str, check: &str) ->
         return Directive::Deny;
     }
     // Update `can_contain` when changing this
-    if contents.contains(&format!("// ignore-tidy-{}", check)) ||
-        contents.contains(&format!("# ignore-tidy-{}", check)) {
+    if contents.contains(&format!("// ignore-tidy-{check}"))
+        || contents.contains(&format!("# ignore-tidy-{check}"))
+        || contents.contains(&format!("/* ignore-tidy-{check} */"))
+    {
         Directive::Ignore(false)
     } else {
         Directive::Deny
@@ -130,23 +180,115 @@ macro_rules! suppressible_tidy_err {
     };
 }
 
+pub fn is_in(full_path: &Path, parent_folder_to_find: &str, folder_to_find: &str) -> bool {
+    if let Some(parent) = full_path.parent() {
+        if parent.file_name().map_or_else(
+            || false,
+            |f| {
+                f.to_string_lossy() == folder_to_find
+                    && parent
+                        .parent()
+                        .and_then(|f| f.file_name())
+                        .map_or_else(|| false, |f| f == parent_folder_to_find)
+            },
+        ) {
+            true
+        } else {
+            is_in(parent, parent_folder_to_find, folder_to_find)
+        }
+    } else {
+        false
+    }
+}
+
+fn skip_markdown_path(path: &Path) -> bool {
+    // These aren't ready for tidy.
+    const SKIP_MD: &[&str] = &[
+        "src/doc/edition-guide",
+        "src/doc/embedded-book",
+        "src/doc/nomicon",
+        "src/doc/reference",
+        "src/doc/rust-by-example",
+        "src/doc/rustc-dev-guide",
+    ];
+    SKIP_MD.iter().any(|p| path.ends_with(p))
+}
+
+fn is_unexplained_ignore(extension: &str, line: &str) -> bool {
+    if !line.ends_with("```ignore") && !line.ends_with("```rust,ignore") {
+        return false;
+    }
+    if extension == "md" && line.trim().starts_with("//") {
+        // Markdown examples may include doc comments with ignore inside a
+        // code block.
+        return false;
+    }
+    true
+}
+
 pub fn check(path: &Path, bad: &mut bool) {
-    super::walk(path, &mut super::filter_dirs, &mut |entry, contents| {
+    fn skip(path: &Path) -> bool {
+        filter_dirs(path) || skip_markdown_path(path)
+    }
+    let problematic_consts_strings: Vec<String> = (PROBLEMATIC_CONSTS.iter().map(u32::to_string))
+        .chain(PROBLEMATIC_CONSTS.iter().map(|v| format!("{:x}", v)))
+        .chain(PROBLEMATIC_CONSTS.iter().map(|v| format!("{:X}", v)))
+        .collect();
+    let problematic_regex = RegexSet::new(problematic_consts_strings.as_slice()).unwrap();
+    walk(path, &mut skip, &mut |entry, contents| {
         let file = entry.path();
         let filename = file.file_name().unwrap().to_string_lossy();
-        let extensions = [".rs", ".py", ".js", ".sh", ".c", ".cpp", ".h"];
-        if extensions.iter().all(|e| !filename.ends_with(e)) ||
-           filename.starts_with(".#") {
-            return
+        let extensions =
+            [".rs", ".py", ".js", ".sh", ".c", ".cpp", ".h", ".md", ".css", ".ftl", ".goml"];
+        if extensions.iter().all(|e| !filename.ends_with(e)) || filename.starts_with(".#") {
+            return;
+        }
+
+        let is_style_file = filename.ends_with(".css");
+        let under_rustfmt = filename.ends_with(".rs") &&
+            // This list should ideally be sourced from rustfmt.toml but we don't want to add a toml
+            // parser to tidy.
+            !file.ancestors().any(|a| {
+                (a.ends_with("tests") && a.join("COMPILER_TESTS.md").exists()) ||
+                    a.ends_with("src/doc/book")
+            });
+
+        if is_style_file && !is_in(file, "src", "librustdoc") {
+            // We only check CSS files in rustdoc.
+            return;
         }
 
         if contents.is_empty() {
             tidy_error!(bad, "{}: empty file", file.display());
         }
 
-        let can_contain = contents.contains("// ignore-tidy-") ||
-            contents.contains("# ignore-tidy-");
+        let extension = file.extension().unwrap().to_string_lossy();
+        let is_error_code = extension == "md" && is_in(file, "src", "error_codes");
+        let is_goml_code = extension == "goml";
+
+        let max_columns = if is_error_code {
+            ERROR_CODE_COLS
+        } else if is_goml_code {
+            GOML_COLS
+        } else {
+            COLS
+        };
+
+        let can_contain = contents.contains("// ignore-tidy-")
+            || contents.contains("# ignore-tidy-")
+            || contents.contains("/* ignore-tidy-");
+        // Enable testing ICE's that require specific (untidy)
+        // file formats easily eg. `issue-1234-ignore-tidy.rs`
+        if filename.contains("ignore-tidy") {
+            return;
+        }
+        // apfloat shouldn't be changed because of license problems
+        if is_in(file, "compiler", "rustc_apfloat") {
+            return;
+        }
         let mut skip_cr = contains_ignore_directive(can_contain, &contents, "cr");
+        let mut skip_undocumented_unsafe =
+            contains_ignore_directive(can_contain, &contents, "undocumented-unsafe");
         let mut skip_tab = contains_ignore_directive(can_contain, &contents, "tab");
         let mut skip_line_length = contains_ignore_directive(can_contain, &contents, "linelength");
         let mut skip_file_length = contains_ignore_directive(can_contain, &contents, "filelength");
@@ -154,67 +296,141 @@ pub fn check(path: &Path, bad: &mut bool) {
             contains_ignore_directive(can_contain, &contents, "end-whitespace");
         let mut skip_trailing_newlines =
             contains_ignore_directive(can_contain, &contents, "trailing-newlines");
+        let mut skip_leading_newlines =
+            contains_ignore_directive(can_contain, &contents, "leading-newlines");
         let mut skip_copyright = contains_ignore_directive(can_contain, &contents, "copyright");
+        let mut skip_dbg = contains_ignore_directive(can_contain, &contents, "dbg");
         let mut leading_new_lines = false;
         let mut trailing_new_lines = 0;
         let mut lines = 0;
+        let mut last_safety_comment = false;
+        let is_test = file.components().any(|c| c.as_os_str() == "tests");
+        // scanning the whole file for multiple needles at once is more efficient than
+        // executing lines times needles separate searches.
+        let any_problematic_line = problematic_regex.is_match(contents);
         for (i, line) in contents.split('\n').enumerate() {
+            if line.is_empty() {
+                if i == 0 {
+                    leading_new_lines = true;
+                }
+                trailing_new_lines += 1;
+                continue;
+            } else {
+                trailing_new_lines = 0;
+            }
+
+            let trimmed = line.trim();
+
+            if !trimmed.starts_with("//") {
+                lines += 1;
+            }
+
             let mut err = |msg: &str| {
                 tidy_error!(bad, "{}:{}: {}", file.display(), i + 1, msg);
             };
-            if line.chars().count() > COLS && !long_line_is_ok(line) {
+
+            if trimmed.contains("dbg!")
+                && !trimmed.starts_with("//")
+                && !file.ancestors().any(|a| {
+                    (a.ends_with("tests") && a.join("COMPILER_TESTS.md").exists())
+                        || a.ends_with("library/alloc/tests")
+                })
+                && filename != "tests.rs"
+            {
+                suppressible_tidy_err!(
+                    err,
+                    skip_dbg,
+                    "`dbg!` macro is intended as a debugging tool. It should not be in version control."
+                )
+            }
+
+            if !under_rustfmt
+                && line.chars().count() > max_columns
+                && !long_line_is_ok(&extension, is_error_code, max_columns, line)
+            {
                 suppressible_tidy_err!(
                     err,
                     skip_line_length,
-                    &format!("line longer than {} chars", COLS)
+                    &format!("line longer than {max_columns} chars")
                 );
             }
-            if line.contains('\t') {
+            if !is_style_file && line.contains('\t') {
                 suppressible_tidy_err!(err, skip_tab, "tab character");
             }
             if line.ends_with(' ') || line.ends_with('\t') {
                 suppressible_tidy_err!(err, skip_end_whitespace, "trailing whitespace");
             }
+            if is_style_file && line.starts_with(' ') {
+                err("CSS files use tabs for indent");
+            }
             if line.contains('\r') {
                 suppressible_tidy_err!(err, skip_cr, "CR character");
             }
             if filename != "style.rs" {
-                if line.contains("TODO") {
+                if trimmed.contains("TODO") {
                     err("TODO is deprecated; use FIXME")
                 }
-                if line.contains("//") && line.contains(" XXX") {
+                if trimmed.contains("//") && trimmed.contains(" XXX") {
                     err("XXX is deprecated; use FIXME")
                 }
+                if any_problematic_line {
+                    for s in problematic_consts_strings.iter() {
+                        if trimmed.contains(s) {
+                            err("Don't use magic numbers that spell things (consider 0x12345678)");
+                        }
+                    }
+                }
             }
-            if (line.starts_with("// Copyright") ||
-                line.starts_with("# Copyright") ||
-                line.starts_with("Copyright"))
-                && (line.contains("Rust Developers") ||
-                    line.contains("Rust Project Developers")) {
+            // for now we just check libcore
+            if trimmed.contains("unsafe {") && !trimmed.starts_with("//") && !last_safety_comment {
+                if file.components().any(|c| c.as_os_str() == "core") && !is_test {
+                    suppressible_tidy_err!(err, skip_undocumented_unsafe, "undocumented unsafe");
+                }
+            }
+            if trimmed.contains("// SAFETY:") {
+                last_safety_comment = true;
+            } else if trimmed.starts_with("//") || trimmed.is_empty() {
+                // keep previous value
+            } else {
+                last_safety_comment = false;
+            }
+            if (line.starts_with("// Copyright")
+                || line.starts_with("# Copyright")
+                || line.starts_with("Copyright"))
+                && (trimmed.contains("Rust Developers")
+                    || trimmed.contains("Rust Project Developers"))
+            {
                 suppressible_tidy_err!(
                     err,
                     skip_copyright,
                     "copyright notices attributed to the Rust Project Developers are deprecated"
                 );
             }
-            if line.ends_with("```ignore") || line.ends_with("```rust,ignore") {
+            if is_unexplained_ignore(&extension, line) {
                 err(UNEXPLAINED_IGNORE_DOCTEST_INFO);
             }
             if filename.ends_with(".cpp") && line.contains("llvm_unreachable") {
                 err(LLVM_UNREACHABLE_INFO);
             }
-            if line.is_empty() {
-                if i == 0 {
-                    leading_new_lines = true;
-                }
-                trailing_new_lines += 1;
-            } else {
-                trailing_new_lines = 0;
+
+            // For now only enforce in compiler
+            let is_compiler = || file.components().any(|c| c.as_os_str() == "compiler");
+            if is_compiler()
+                && line.contains("//")
+                && line
+                    .chars()
+                    .collect::<Vec<_>>()
+                    .windows(4)
+                    .any(|cs| matches!(cs, ['.', ' ', ' ', last] if last.is_alphabetic()))
+            {
+                err(DOUBLE_SPACE_AFTER_DOT)
             }
-            lines = i;
         }
         if leading_new_lines {
-            tidy_error!(bad, "{}: leading newline", file.display());
+            let mut err = |_| {
+                tidy_error!(bad, "{}: leading newline", file.display());
+            };
+            suppressible_tidy_err!(err, skip_leading_newlines, "mising leading newline");
         }
         let mut err = |msg: &str| {
             tidy_error!(bad, "{}: {}", file.display(), msg);
@@ -225,7 +441,7 @@ pub fn check(path: &Path, bad: &mut bool) {
             n => suppressible_tidy_err!(
                 err,
                 skip_trailing_newlines,
-                &format!("too many trailing newlines ({})", n)
+                &format!("too many trailing newlines ({n})")
             ),
         };
         if lines > LINES {
@@ -247,20 +463,21 @@ pub fn check(path: &Path, bad: &mut bool) {
         if let Directive::Ignore(false) = skip_tab {
             tidy_error!(bad, "{}: ignoring tab characters unnecessarily", file.display());
         }
-        if let Directive::Ignore(false) = skip_line_length {
-            tidy_error!(bad, "{}: ignoring line length unnecessarily", file.display());
-        }
-        if let Directive::Ignore(false) = skip_file_length {
-            tidy_error!(bad, "{}: ignoring file length unnecessarily", file.display());
-        }
         if let Directive::Ignore(false) = skip_end_whitespace {
             tidy_error!(bad, "{}: ignoring trailing whitespace unnecessarily", file.display());
         }
         if let Directive::Ignore(false) = skip_trailing_newlines {
             tidy_error!(bad, "{}: ignoring trailing newlines unnecessarily", file.display());
         }
+        if let Directive::Ignore(false) = skip_leading_newlines {
+            tidy_error!(bad, "{}: ignoring leading newlines unnecessarily", file.display());
+        }
         if let Directive::Ignore(false) = skip_copyright {
             tidy_error!(bad, "{}: ignoring copyright unnecessarily", file.display());
         }
+        // We deliberately do not warn about these being unnecessary,
+        // that would just lead to annoying churn.
+        let _unused = skip_line_length;
+        let _unused = skip_file_length;
     })
 }