Merge #10400

10400: fix: fix format string highlighting for `todo!` and `unimplemented!` r=jonas-schievink a=jonas-schievink

Part of #10394

These macros require us to see through the `const_format_args!` invocation the panic macros generate, for that we have to add it to our supported built-in macros.

I've also made the macros in the test `#[macro_export]` (turns out they didn't all resolve correctly before this), which changes the output slightly.

bors r+

Co-authored-by: Jonas Schievink <[email protected]>

Author: bors[bot]

crates/hir_expand/src/builtin_macro.rs

@@ -103,6 +103,7 @@ register_builtin! {
     (assert, Assert) => assert_expand,
     (stringify, Stringify) => stringify_expand,
     (format_args, FormatArgs) => format_args_expand,
+    (const_format_args, ConstFormatArgs) => format_args_expand,
     // format_args_nl only differs in that it adds a newline in the end,
     // so we use the same stub expansion for now
     (format_args_nl, FormatArgsNl) => format_args_expand,

crates/hir_expand/src/name.rs

@@ -211,6 +211,7 @@ pub mod known {
         // Builtin macros
         file,
         column,
+        const_format_args,
         compile_error,
         line,
         module_path,

crates/ide/src/syntax_highlighting/format.rs

@@ -38,6 +38,9 @@ fn is_format_string(string: &ast::String) -> Option<()> {
         return None;
     }
 
+    // NB: we match against `panic_2015`/`panic_2021` here because they have a special-cased arm for
+    // `"{}"`, which otherwise wouldn't get highlighted.
+
     let first_literal = parent
         .children_with_tokens()
         .find_map(|it| it.as_token().cloned().and_then(ast::String::cast))?;

crates/ide/src/syntax_highlighting/test_data/highlight_strings.html

@@ -46,10 +46,14 @@
     <span class="brace">}</span><span class="parenthesis">)</span>
 <span class="brace">}</span>
 <span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">rustc_builtin_macro</span><span class="attribute attribute">]</span>
-<span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">format_args_nl</span> <span class="brace">{</span>
-    <span class="parenthesis">(</span><span class="punctuation">$</span>fmt<span class="colon">:</span>expr<span class="parenthesis">)</span> <span class="operator">=</span><span class="angle">&gt;</span> <span class="brace">{</span><span class="brace">{</span> <span class="comment">/* compiler built-in */</span> <span class="brace">}</span><span class="brace">}</span><span class="semicolon">;</span>
-    <span class="parenthesis">(</span><span class="punctuation">$</span>fmt<span class="colon">:</span>expr<span class="comma">,</span> <span class="punctuation">$</span><span class="parenthesis">(</span><span class="punctuation">$</span>args<span class="colon">:</span>tt<span class="parenthesis">)</span><span class="punctuation">*</span><span class="parenthesis">)</span> <span class="operator">=</span><span class="angle">&gt;</span> <span class="brace">{</span><span class="brace">{</span> <span class="comment">/* compiler built-in */</span> <span class="brace">}</span><span class="brace">}</span><span class="semicolon">;</span>
-<span class="brace">}</span>
+<span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">macro_export</span><span class="attribute attribute">]</span>
+<span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">format_args</span> <span class="brace">{</span><span class="brace">}</span>
+<span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">rustc_builtin_macro</span><span class="attribute attribute">]</span>
+<span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">macro_export</span><span class="attribute attribute">]</span>
+<span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">const_format_args</span> <span class="brace">{</span><span class="brace">}</span>
+<span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">rustc_builtin_macro</span><span class="attribute attribute">]</span>
+<span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">macro_export</span><span class="attribute attribute">]</span>
+<span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">format_args_nl</span> <span class="brace">{</span><span class="brace">}</span>
 
 <span class="keyword">mod</span> <span class="module declaration">panic</span> <span class="brace">{</span>
     <span class="keyword">pub</span> <span class="keyword">macro</span> <span class="macro declaration">panic_2015</span> <span class="brace">{</span>
@@ -79,6 +83,11 @@
 <span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="builtin_attr attribute">rustc_builtin_macro</span><span class="attribute attribute">]</span>
 <span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">assert</span> <span class="brace">{</span><span class="brace">}</span>
 
+<span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">toho</span> <span class="brace">{</span>
+    <span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="operator">=</span><span class="angle">&gt;</span> <span class="parenthesis">(</span><span class="punctuation">$</span>crate<span class="colon">:</span><span class="colon">:</span>panic<span class="punctuation">!</span><span class="parenthesis">(</span><span class="string_literal">"not yet implemented"</span><span class="parenthesis">)</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+    <span class="parenthesis">(</span><span class="punctuation">$</span><span class="parenthesis">(</span><span class="punctuation">$</span>arg<span class="colon">:</span>tt<span class="parenthesis">)</span><span class="punctuation">+</span><span class="parenthesis">)</span> <span class="operator">=</span><span class="angle">&gt;</span> <span class="parenthesis">(</span><span class="punctuation">$</span>crate<span class="colon">:</span><span class="colon">:</span>panic<span class="punctuation">!</span><span class="parenthesis">(</span><span class="string_literal">"not yet implemented: {}"</span><span class="comma">,</span> <span class="punctuation">$</span>crate<span class="colon">:</span><span class="colon">:</span>format_args<span class="punctuation">!</span><span class="parenthesis">(</span><span class="punctuation">$</span><span class="parenthesis">(</span><span class="punctuation">$</span>arg<span class="parenthesis">)</span><span class="punctuation">+</span><span class="parenthesis">)</span><span class="parenthesis">)</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+<span class="brace">}</span>
+
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
     <span class="comment">// from https://doc.rust-lang.org/std/fmt/index.html</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello"</span><span class="parenthesis">)</span><span class="semicolon">;</span>                 <span class="comment">// =&gt; "Hello"</span>
@@ -104,7 +113,7 @@
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">+</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="comma">,</span> <span class="numeric_literal">5</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="comma">,</span> <span class="numeric_literal">27</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="comma">,</span> <span class="numeric_literal">5</span><span class="parenthesis">)</span><span class="semicolon">;</span>
-    <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="comma">,</span> <span class="punctuation">-</span><span class="numeric_literal">5</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+    <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="comma">,</span> <span class="numeric_literal">-</span><span class="numeric_literal">5</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="numeric_literal">0</span><span class="numeric_literal">10</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="comma">,</span> <span class="numeric_literal">27</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> <span class="string_literal">"x"</span><span class="comma">,</span> <span class="numeric_literal">0.01</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">0</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> <span class="numeric_literal">5</span><span class="comma">,</span> <span class="string_literal">"x"</span><span class="comma">,</span> <span class="numeric_literal">0.01</span><span class="parenthesis">)</span><span class="semicolon">;</span>
@@ -127,9 +136,10 @@
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="escape_sequence">\x41</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> A <span class="operator">=</span> <span class="numeric_literal">92</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">ничоси</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> ничоси <span class="operator">=</span> <span class="numeric_literal">92</span><span class="parenthesis">)</span><span class="semicolon">;</span>
 
-    <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="variable">x</span><span class="format_specifier">?</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> "</span><span class="comma">,</span> thingy<span class="comma">,</span> n2<span class="parenthesis">)</span><span class="semicolon">;</span>
+    <span class="macro">println!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="variable">x</span><span class="format_specifier">?</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> "</span><span class="comma">,</span> <span class="unresolved_reference">thingy</span><span class="comma">,</span> <span class="unresolved_reference">n2</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">panic!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> <span class="numeric_literal">0</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">panic!</span><span class="parenthesis">(</span><span class="string_literal">"more </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> <span class="numeric_literal">1</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">assert!</span><span class="parenthesis">(</span><span class="bool_literal">true</span><span class="comma">,</span> <span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="comma">,</span> <span class="numeric_literal">1</span><span class="parenthesis">)</span><span class="semicolon">;</span>
     <span class="macro">assert!</span><span class="parenthesis">(</span><span class="bool_literal">true</span><span class="comma">,</span> <span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> asdasd"</span><span class="comma">,</span> <span class="numeric_literal">1</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+    <span class="macro">toho!</span><span class="parenthesis">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">fmt"</span><span class="comma">,</span> <span class="numeric_literal">0</span><span class="parenthesis">)</span><span class="semicolon">;</span>
 <span class="brace">}</span></code></pre>

crates/ide/src/syntax_highlighting/tests.rs

@@ -441,10 +441,14 @@ macro_rules! println {
     })
 }
 #[rustc_builtin_macro]
-macro_rules! format_args_nl {
-    ($fmt:expr) => {{ /* compiler built-in */ }};
-    ($fmt:expr, $($args:tt)*) => {{ /* compiler built-in */ }};
-}
+#[macro_export]
+macro_rules! format_args {}
+#[rustc_builtin_macro]
+#[macro_export]
+macro_rules! const_format_args {}
+#[rustc_builtin_macro]
+#[macro_export]
+macro_rules! format_args_nl {}
 
 mod panic {
     pub macro panic_2015 {
@@ -474,6 +478,11 @@ macro_rules! panic {}
 #[rustc_builtin_macro]
 macro_rules! assert {}
 
+macro_rules! toho {
+    () => ($crate::panic!("not yet implemented"));
+    ($($arg:tt)+) => ($crate::panic!("not yet implemented: {}", $crate::format_args!($($arg)+)));
+}
+
 fn main() {
     // from https://doc.rust-lang.org/std/fmt/index.html
     println!("Hello");                 // => "Hello"
@@ -527,6 +536,7 @@ fn main() {
     panic!("more {}", 1);
     assert!(true, "{}", 1);
     assert!(true, "{} asdasd", 1);
+    toho!("{}fmt", 0);
 }"#
         .trim(),
         expect_file!["./test_data/highlight_strings.html"],