fix(c): only match real atomic_* type names, not atomic functions

CHANGES.md

@@ -6,6 +6,7 @@ Core Grammars:
 - fix(rust) recognize `\\` and `\"` char-literal escapes so highlighting doesn't leak, issue #4351 [Sarath Francis][]
 - fix(cmake) only highlight standalone numbers, not digits that begin an identifier (e.g. `3rdparty`), issue #4170 [MarkXian][]
 - fix(cpp) require a word boundary before numeric literals so digits inside identifiers aren't highlighted as numbers, issue #4231 [Mark Xian][]
+- fix(c) only match real `atomic_*` type names, not C11 atomic functions, issue #3837 [MarkXian][]
 - enh(python) add missing builtins: `aiter` and `anext` (Python 3.10), `frozendict` and `sentinel` (Python 3.15) [Hugo van Kemenade][]
 
 Documentation:

src/languages/c.js

@@ -21,11 +21,53 @@ export default function(hljs) {
   + ')';
 
 
+  // C11 <stdatomic.h> atomic type names. This is an explicit whitelist so that
+  // C11 atomic *functions* (atomic_init, atomic_store, atomic_load,
+  // atomic_fetch_add, ...) are not mistakenly highlighted as types. See #3837.
+  const ATOMIC_TYPES = regex.concat(/\batomic_/, regex.either(
+    'bool',
+    'char',
+    'schar',
+    'uchar',
+    'short',
+    'ushort',
+    'int',
+    'uint',
+    'long',
+    'ulong',
+    'llong',
+    'ullong',
+    'char16_t',
+    'char32_t',
+    'wchar_t',
+    'int_least8_t',
+    'uint_least8_t',
+    'int_least16_t',
+    'uint_least16_t',
+    'int_least32_t',
+    'uint_least32_t',
+    'int_least64_t',
+    'uint_least64_t',
+    'int_fast8_t',
+    'uint_fast8_t',
+    'int_fast16_t',
+    'uint_fast16_t',
+    'int_fast32_t',
+    'uint_fast32_t',
+    'int_fast64_t',
+    'uint_fast64_t',
+    'intptr_t',
+    'uintptr_t',
+    'size_t',
+    'ptrdiff_t',
+    'intmax_t',
+    'uintmax_t'
+  ), /\b/);
   const TYPES = {
     className: 'type',
     variants: [
       { begin: '\\b[a-z\\d_]*_t\\b' },
-      { match: /\batomic_[a-z]{3,6}\b/ }
+      { match: ATOMIC_TYPES }
     ]
 
   };

test/markup/c/atomic-types.expect.txt

@@ -0,0 +1,7 @@
+<span class="hljs-type">atomic_int</span> x;
+<span class="hljs-type">atomic_bool</span> flag;
+<span class="hljs-type">atomic_uint</span> counter;
+atomic_store(&amp;x, <span class="hljs-number">1</span>);
+atomic_load(&amp;x);
+atomic_init(&amp;x, <span class="hljs-number">0</span>);
+atomic_fetch_add(&amp;x, <span class="hljs-number">2</span>);

test/markup/c/atomic-types.txt

@@ -0,0 +1,7 @@
+atomic_int x;
+atomic_bool flag;
+atomic_uint counter;
+atomic_store(&x, 1);
+atomic_load(&x);
+atomic_init(&x, 0);
+atomic_fetch_add(&x, 2);