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Support bitfields that contain constant integral expressions #129

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Merged
merged 2 commits into from
Sep 6, 2025
Merged

Support bitfields that contain constant integral expressions #129

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4d69eba
Move class bitfield tests to their own file
virtuald Sep 6, 2025
793d4f1
Support bitfields that contain constant integral expressions
virtuald Sep 6, 2025
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12 changes: 8 additions & 4 deletions cxxheaderparser/parser.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1407,10 +1407,14 @@ def _discard_ctor_initializer(self) -> None:
# Variable parsing
#

def _parse_bitfield(self) -> int:
# is a integral constant expression... for now, just do integers
tok = self._next_token_must_be("INT_CONST_DEC")
return int(tok.value)
def _parse_bitfield(self) -> typing.Union[int, Value]:
# Convert to integer for backwards compat
tok = self.lex.token_if("INT_CONST_DEC")
if tok is not None:
return int(tok.value)

# But also support weird things too
return self._create_value(self._consume_value_until([], ";"))

def _parse_field(
self,
Expand Down
2 changes: 1 addition & 1 deletion cxxheaderparser/types.py
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Expand Up @@ -862,7 +862,7 @@ class Field:
name: typing.Optional[str] = None

value: typing.Optional[Value] = None
bits: typing.Optional[int] = None
bits: typing.Union[None, int, Value] = None

constexpr: bool = False
mutable: bool = False
Expand Down
159 changes: 0 additions & 159 deletions tests/test_class.py
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,6 @@
Enumerator,
Field,
ForwardDecl,
Function,
FundamentalSpecifier,
Method,
MoveReference,
Expand Down Expand Up @@ -1416,164 +1415,6 @@ def test_class_volatile_move_deleted_fn() -> None:
)


def test_class_bitfield_1() -> None:
content = """
struct S {
// will usually occupy 2 bytes:
// 3 bits: value of b1
// 2 bits: unused
// 6 bits: value of b2
// 2 bits: value of b3
// 3 bits: unused
unsigned char b1 : 3, : 2, b2 : 6, b3 : 2;
};
"""
data = parse_string(content, cleandoc=True)

assert data == ParsedData(
namespace=NamespaceScope(
classes=[
ClassScope(
class_decl=ClassDecl(
typename=PQName(
segments=[NameSpecifier(name="S")], classkey="struct"
)
),
fields=[
Field(
name="b1",
type=Type(
typename=PQName(
segments=[
FundamentalSpecifier(name="unsigned char")
]
)
),
access="public",
bits=3,
),
Field(
type=Type(
typename=PQName(
segments=[
FundamentalSpecifier(name="unsigned char")
]
)
),
access="public",
bits=2,
),
Field(
name="b2",
type=Type(
typename=PQName(
segments=[
FundamentalSpecifier(name="unsigned char")
]
)
),
access="public",
bits=6,
),
Field(
name="b3",
type=Type(
typename=PQName(
segments=[
FundamentalSpecifier(name="unsigned char")
]
)
),
access="public",
bits=2,
),
],
)
]
)
)


def test_class_bitfield_2() -> None:
content = """
struct HAL_ControlWord {
int x : 1;
int y : 1;
};
typedef struct HAL_ControlWord HAL_ControlWord;
int HAL_GetControlWord(HAL_ControlWord *controlWord);
"""
data = parse_string(content, cleandoc=True)

assert data == ParsedData(
namespace=NamespaceScope(
classes=[
ClassScope(
class_decl=ClassDecl(
typename=PQName(
segments=[NameSpecifier(name="HAL_ControlWord")],
classkey="struct",
)
),
fields=[
Field(
name="x",
type=Type(
typename=PQName(
segments=[FundamentalSpecifier(name="int")]
)
),
access="public",
bits=1,
),
Field(
name="y",
type=Type(
typename=PQName(
segments=[FundamentalSpecifier(name="int")]
)
),
access="public",
bits=1,
),
],
)
],
functions=[
Function(
return_type=Type(
typename=PQName(segments=[FundamentalSpecifier(name="int")])
),
name=PQName(segments=[NameSpecifier(name="HAL_GetControlWord")]),
parameters=[
Parameter(
type=Pointer(
ptr_to=Type(
typename=PQName(
segments=[NameSpecifier(name="HAL_ControlWord")]
)
)
),
name="controlWord",
)
],
)
],
typedefs=[
Typedef(
type=Type(
typename=PQName(
segments=[NameSpecifier(name="HAL_ControlWord")],
classkey="struct",
)
),
name="HAL_ControlWord",
)
],
)
)


def test_class_anon_struct_as_globalvar() -> None:
content = """
struct {
Expand Down
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