C and C++, parsing function attributes

Fixes sphinx-doc/sphinx#8114

6 files changed, 44 insertions, 14 deletions

diff --git a/CHANGES b/CHANGES
index 282646967..50008f519 100644
--- a/CHANGES
+++ b/CHANGES
@@ -36,6 +36,7 @@ Features added
 
 * #8095: napoleon: Add :confval:`napoleon_preprocess_types` to enable the type
   preprocessor for numpy style docstrings
+* #8114: C and C++, parse function attributes after parameters and qualifiers.
 
 Bugs fixed
 ----------
diff --git a/sphinx/domains/c.py b/sphinx/domains/c.py
index 65786b5de..d8ccc2e3d 100644
--- a/sphinx/domains/c.py
+++ b/sphinx/domains/c.py
@@ -32,7 +32,7 @@ from sphinx.transforms import SphinxTransform
 from sphinx.transforms.post_transforms import ReferencesResolver
 from sphinx.util import logging
 from sphinx.util.cfamily import (
-    NoOldIdError, ASTBaseBase, ASTBaseParenExprList,
+    NoOldIdError, ASTBaseBase, ASTAttribute, ASTBaseParenExprList,
     verify_description_mode, StringifyTransform,
     BaseParser, DefinitionError, UnsupportedMultiCharacterCharLiteral,
     identifier_re, anon_identifier_re, integer_literal_re, octal_literal_re,
@@ -652,8 +652,9 @@ class ASTFunctionParameter(ASTBase):
 
 
 class ASTParameters(ASTBase):
-    def __init__(self, args: List[ASTFunctionParameter]) -> None:
+    def __init__(self, args: List[ASTFunctionParameter], attrs: List[ASTAttribute]) -> None:
         self.args = args
+        self.attrs = attrs
 
     @property
     def function_params(self) -> List[ASTFunctionParameter]:
@@ -669,6 +670,9 @@ class ASTParameters(ASTBase):
             first = False
             res.append(str(a))
         res.append(')')
+        for attr in self.attrs:
+            res.append(' ')
+            res.append(transform(attr))
         return ''.join(res)
 
     def describe_signature(self, signode: TextElement, mode: str,
@@ -683,6 +687,9 @@ class ASTParameters(ASTBase):
                 arg.describe_signature(param, 'markType', env, symbol=symbol)
             paramlist += param
         signode += paramlist
+        for attr in self.attrs:
+            signode += nodes.Text(' ')
+            attr.describe_signature(signode)
 
 
 class ASTDeclSpecsSimple(ASTBaseBase):
@@ -2572,7 +2579,15 @@ class DefinitionParser(BaseParser):
                     self.fail(
                         'Expecting "," or ")" in parameters, '
                         'got "%s".' % self.current_char)
-        return ASTParameters(args)
+
+        attrs = []
+        while True:
+            attr = self._parse_attribute()
+            if attr is None:
+                break
+            attrs.append(attr)
+
+        return ASTParameters(args, attrs)
 
     def _parse_decl_specs_simple(self, outer: str, typed: bool) -> ASTDeclSpecsSimple:
         """Just parse the simple ones."""
diff --git a/sphinx/domains/cpp.py b/sphinx/domains/cpp.py
index 0b3c02e83..92d578427 100644
--- a/sphinx/domains/cpp.py
+++ b/sphinx/domains/cpp.py
@@ -1879,7 +1879,8 @@ class ASTNoexceptSpec(ASTBase):
 class ASTParametersQualifiers(ASTBase):
     def __init__(self, args: List[ASTFunctionParameter], volatile: bool, const: bool,
                  refQual: str, exceptionSpec: ASTNoexceptSpec, trailingReturn: "ASTType",
-                 override: bool, final: bool, initializer: str) -> None:
+                 override: bool, final: bool, attrs: List[ASTAttribute],
+                 initializer: str) -> None:
         self.args = args
         self.volatile = volatile
         self.const = const
@@ -1888,6 +1889,7 @@ class ASTParametersQualifiers(ASTBase):
         self.trailingReturn = trailingReturn
         self.override = override
         self.final = final
+        self.attrs = attrs
         self.initializer = initializer
 
     @property
@@ -1947,6 +1949,9 @@ class ASTParametersQualifiers(ASTBase):
             res.append(' final')
         if self.override:
             res.append(' override')
+        for attr in self.attrs:
+            res.append(' ')
+            res.append(transform(attr))
         if self.initializer:
             res.append(' = ')
             res.append(self.initializer)
@@ -1988,6 +1993,9 @@ class ASTParametersQualifiers(ASTBase):
             _add_anno(signode, 'final')
         if self.override:
             _add_anno(signode, 'override')
+        for attr in self.attrs:
+            signode += nodes.Text(' ')
+            attr.describe_signature(signode)
         if self.initializer:
             _add_text(signode, '= ' + str(self.initializer))
 
@@ -5709,6 +5717,13 @@ class DefinitionParser(BaseParser):
             override = self.skip_word_and_ws(
                 'override')  # they can be permuted
 
+        attrs = []
+        while True:
+            attr = self._parse_attribute()
+            if attr is None:
+                break
+            attrs.append(attr)
+
         self.skip_ws()
         initializer = None
         if self.skip_string('='):
@@ -5725,7 +5740,7 @@ class DefinitionParser(BaseParser):
 
         return ASTParametersQualifiers(
             args, volatile, const, refQual, exceptionSpec, trailingReturn,
-            override, final, initializer)
+            override, final, attrs, initializer)
 
     def _parse_decl_specs_simple(self, outer: str, typed: bool) -> ASTDeclSpecsSimple:
         """Just parse the simple ones."""
diff --git a/sphinx/util/cfamily.py b/sphinx/util/cfamily.py
index a67b2a0ad..0edea128c 100644
--- a/sphinx/util/cfamily.py
+++ b/sphinx/util/cfamily.py
@@ -391,7 +391,7 @@ class BaseParser:
                       % startPos)
         return self.definition[startPos:self.pos]
 
-    def _parse_attribute(self) -> ASTAttribute:
+    def _parse_attribute(self) -> Optional[ASTAttribute]:
         self.skip_ws()
         # try C++11 style
         startPos = self.pos
diff --git a/tests/test_domain_c.py b/tests/test_domain_c.py
index 71bf251e9..b6f72287e 100644
--- a/tests/test_domain_c.py
+++ b/tests/test_domain_c.py
@@ -497,17 +497,16 @@ def test_attributes():
         parse('member', 'paren_attr({]}) int f')
 
     # position: decl specs
-    check('function', 'static inline __attribute__(()) void f()',
-          {1: 'f'},
+    check('function', 'static inline __attribute__(()) void f()', {1: 'f'},
           output='__attribute__(()) static inline void f()')
-    check('function', '[[attr1]] [[attr2]] void f()',
-          {1: 'f'},
-          output='[[attr1]] [[attr2]] void f()')
+    check('function', '[[attr1]] [[attr2]] void f()', {1: 'f'})
     # position: declarator
     check('member', 'int *[[attr]] i', {1: 'i'})
     check('member', 'int *const [[attr]] volatile i', {1: 'i'},
           output='int *[[attr]] volatile const i')
     check('member', 'int *[[attr]] *i', {1: 'i'})
+    # position: parameters
+    check('function', 'void f() [[attr1]] [[attr2]]', {1: 'f'})
 
     # issue michaeljones/breathe#500
     check('function', 'LIGHTGBM_C_EXPORT int LGBM_BoosterFree(int handle)',
diff --git a/tests/test_domain_cpp.py b/tests/test_domain_cpp.py
index 513205cab..558d69911 100644
--- a/tests/test_domain_cpp.py
+++ b/tests/test_domain_cpp.py
@@ -938,15 +938,15 @@ def test_attributes():
     check('function', 'static inline __attribute__(()) void f()',
           {1: 'f', 2: '1fv'},
           output='__attribute__(()) static inline void f()')
-    check('function', '[[attr1]] [[attr2]] void f()',
-          {1: 'f', 2: '1fv'},
-          output='[[attr1]] [[attr2]] void f()')
+    check('function', '[[attr1]] [[attr2]] void f()', {1: 'f', 2: '1fv'})
     # position: declarator
     check('member', 'int *[[attr]] i', {1: 'i__iP', 2: '1i'})
     check('member', 'int *const [[attr]] volatile i', {1: 'i__iPVC', 2: '1i'},
           output='int *[[attr]] volatile const i')
     check('member', 'int &[[attr]] i', {1: 'i__iR', 2: '1i'})
     check('member', 'int *[[attr]] *i', {1: 'i__iPP', 2: '1i'})
+    # position: parameters and qualifiers
+    check('function', 'void f() [[attr1]] [[attr2]]', {1: 'f', 2: '1fv'})
 
 
 def test_xref_parsing():