rustc_expand: Don not beautify doc comments before passing them to ma…

…cros

Beautify all doc strings in rustdoc instead, including those in `#[doc]` attributes

src/librustc_ast/util/comments.rs

@@ -1,5 +1,4 @@
 use crate::ast::AttrStyle;
-use crate::token::CommentKind;
 use rustc_span::source_map::SourceMap;
 use rustc_span::{BytePos, CharPos, FileName, Pos, Symbol};
 
@@ -64,7 +63,9 @@ pub fn block_doc_comment_style(block_comment: &str, terminated: bool) -> Option<
     }
 }
 
-pub fn strip_doc_comment_decoration(data: Symbol, comment_kind: CommentKind) -> String {
+/// Makes a doc string more presentable to users.
+/// Used by rustdoc and perhaps other tools, but not by rustc.
+pub fn beautify_doc_string(data: Symbol) -> String {
     /// remove whitespace-only lines from the start/end of lines
     fn vertical_trim(lines: Vec<String>) -> Vec<String> {
         let mut i = 0;
@@ -126,18 +127,14 @@ pub fn strip_doc_comment_decoration(data: Symbol, comment_kind: CommentKind) ->
         }
     }
 
-    match comment_kind {
-        CommentKind::Line => {
-            let data = data.as_str();
-            let prefix_len = if data.starts_with('!') { 1 } else { 0 };
-            data[prefix_len..].to_string()
-        }
-        CommentKind::Block => {
-            let lines = data.as_str().lines().map(|s| s.to_string()).collect::<Vec<String>>();
-            let lines = vertical_trim(lines);
-            let lines = horizontal_trim(lines);
-            lines.join("\n")
-        }
+    let data = data.as_str();
+    if data.contains('\n') {
+        let lines = data.lines().map(|s| s.to_string()).collect::<Vec<String>>();
+        let lines = vertical_trim(lines);
+        let lines = horizontal_trim(lines);
+        lines.join("\n")
+    } else {
+        data.to_string()
     }
 }
 

src/librustc_ast/util/comments/tests.rs

@@ -12,7 +12,7 @@ fn line_doc_comments() {
 fn test_block_doc_comment_1() {
     with_default_session_globals(|| {
         let comment = "\n * Test \n **  Test\n *   Test\n";
-        let stripped = strip_doc_comment_decoration(Symbol::intern(comment), CommentKind::Block);
+        let stripped = beautify_doc_string(Symbol::intern(comment));
         assert_eq!(stripped, " Test \n*  Test\n   Test");
     })
 }
@@ -21,7 +21,7 @@ fn test_block_doc_comment_1() {
 fn test_block_doc_comment_2() {
     with_default_session_globals(|| {
         let comment = "\n * Test\n *  Test\n";
-        let stripped = strip_doc_comment_decoration(Symbol::intern(comment), CommentKind::Block);
+        let stripped = beautify_doc_string(Symbol::intern(comment));
         assert_eq!(stripped, " Test\n  Test");
     })
 }
@@ -30,21 +30,21 @@ fn test_block_doc_comment_2() {
 fn test_block_doc_comment_3() {
     with_default_session_globals(|| {
         let comment = "\n let a: *i32;\n *a = 5;\n";
-        let stripped = strip_doc_comment_decoration(Symbol::intern(comment), CommentKind::Block);
+        let stripped = beautify_doc_string(Symbol::intern(comment));
         assert_eq!(stripped, " let a: *i32;\n *a = 5;");
     })
 }
 
 #[test]
 fn test_line_doc_comment() {
     with_default_session_globals(|| {
-        let stripped = strip_doc_comment_decoration(Symbol::intern(" test"), CommentKind::Line);
+        let stripped = beautify_doc_string(Symbol::intern(" test"));
         assert_eq!(stripped, " test");
-        let stripped = strip_doc_comment_decoration(Symbol::intern("! test"), CommentKind::Line);
-        assert_eq!(stripped, " test");
-        let stripped = strip_doc_comment_decoration(Symbol::intern("test"), CommentKind::Line);
-        assert_eq!(stripped, "test");
-        let stripped = strip_doc_comment_decoration(Symbol::intern("!test"), CommentKind::Line);
+        let stripped = beautify_doc_string(Symbol::intern("! test"));
+        assert_eq!(stripped, "! test");
+        let stripped = beautify_doc_string(Symbol::intern("test"));
         assert_eq!(stripped, "test");
+        let stripped = beautify_doc_string(Symbol::intern("!test"));
+        assert_eq!(stripped, "!test");
     })
 }

src/librustc_expand/proc_macro_server.rs

@@ -3,7 +3,6 @@ use crate::base::ExtCtxt;
 use rustc_ast::ast;
 use rustc_ast::token;
 use rustc_ast::tokenstream::{self, DelimSpan, IsJoint::*, TokenStream, TreeAndJoint};
-use rustc_ast::util::comments;
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::Diagnostic;
@@ -148,10 +147,9 @@ impl FromInternal<(TreeAndJoint, &'_ ParseSess, &'_ mut Vec<Self>)>
                 tt!(Punct::new('\'', true))
             }
             Literal(lit) => tt!(Literal { lit }),
-            DocComment(comment_kind, attr_style, data) => {
-                let stripped = comments::strip_doc_comment_decoration(data, comment_kind);
+            DocComment(_, attr_style, data) => {
                 let mut escaped = String::new();
-                for ch in stripped.chars() {
+                for ch in data.as_str().chars() {
                     escaped.extend(ch.escape_debug());
                 }
                 let stream = vec![

src/librustc_parse/parser/mod.rs

@@ -22,7 +22,6 @@ use rustc_ast::ast::{
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, DelimToken, Token, TokenKind};
 use rustc_ast::tokenstream::{self, DelimSpan, TokenStream, TokenTree, TreeAndJoint};
-use rustc_ast::util::comments::strip_doc_comment_decoration;
 use rustc_ast_pretty::pprust;
 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, FatalError, PResult};
 use rustc_session::parse::ParseSess;
@@ -209,20 +208,18 @@ impl TokenCursor {
     }
 
     fn next_desugared(&mut self) -> Token {
-        let (data, comment_kind, attr_style, sp) = match self.next() {
-            Token { kind: token::DocComment(comment_kind, attr_style, data), span } => {
-                (data, comment_kind, attr_style, span)
+        let (data, attr_style, sp) = match self.next() {
+            Token { kind: token::DocComment(_, attr_style, data), span } => {
+                (data, attr_style, span)
             }
             tok => return tok,
         };
 
-        let stripped = strip_doc_comment_decoration(data, comment_kind);
-
         // Searches for the occurrences of `"#*` and returns the minimum number of `#`s
         // required to wrap the text.
         let mut num_of_hashes = 0;
         let mut count = 0;
-        for ch in stripped.chars() {
+        for ch in data.as_str().chars() {
             count = match ch {
                 '"' => 1,
                 '#' if count > 0 => count + 1,
@@ -238,10 +235,7 @@ impl TokenCursor {
             [
                 TokenTree::token(token::Ident(sym::doc, false), sp),
                 TokenTree::token(token::Eq, sp),
-                TokenTree::token(
-                    TokenKind::lit(token::StrRaw(num_of_hashes), Symbol::intern(&stripped), None),
-                    sp,
-                ),
+                TokenTree::token(TokenKind::lit(token::StrRaw(num_of_hashes), data, None), sp),
             ]
             .iter()
             .cloned()

src/librustc_save_analysis/lib.rs

@@ -10,7 +10,7 @@ mod span_utils;
 mod sig;
 
 use rustc_ast::ast::{self};
-use rustc_ast::util::comments::strip_doc_comment_decoration;
+use rustc_ast::util::comments::beautify_doc_string;
 use rustc_ast_pretty::pprust::attribute_to_string;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind as HirDefKind, Res};
@@ -822,11 +822,8 @@ impl<'tcx> SaveContext<'tcx> {
 
         for attr in attrs {
             if let Some(val) = attr.doc_str() {
-                if let ast::AttrKind::DocComment(comment_kind, _) = attr.kind {
-                    result.push_str(&strip_doc_comment_decoration(val, comment_kind));
-                } else {
-                    result.push_str(&val.as_str());
-                }
+                // FIXME: Should save-analysis beautify doc strings itself or leave it to users?
+                result.push_str(&beautify_doc_string(val));
                 result.push('\n');
             } else if attr.check_name(sym::doc) {
                 if let Some(meta_list) = attr.meta_item_list() {

src/librustdoc/clean/types.rs

@@ -10,7 +10,7 @@ use std::{slice, vec};
 
 use rustc_ast::ast::{self, AttrStyle};
 use rustc_ast::attr;
-use rustc_ast::util::comments::strip_doc_comment_decoration;
+use rustc_ast::util::comments::beautify_doc_string;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def::Res;
@@ -506,15 +506,12 @@ impl Attributes {
             .iter()
             .filter_map(|attr| {
                 if let Some(value) = attr.doc_str() {
-                    let (value, mk_fragment): (_, fn(_, _, _) -> _) =
-                        if let ast::AttrKind::DocComment(comment_kind, _) = attr.kind {
-                            (
-                                strip_doc_comment_decoration(value, comment_kind),
-                                DocFragment::SugaredDoc,
-                            )
-                        } else {
-                            (value.to_string(), DocFragment::RawDoc)
-                        };
+                    let value = beautify_doc_string(value);
+                    let mk_fragment: fn(_, _, _) -> _ = if attr.is_doc_comment() {
+                        DocFragment::SugaredDoc
+                    } else {
+                        DocFragment::RawDoc
+                    };
 
                     let line = doc_line;
                     doc_line += value.lines().count();