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Revert "reserve correct space for bitfields"

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This reverts commit 22cb693889.
This commit is contained in:
Veikka Tuominen 2022-05-29 12:04:50 +03:00
parent 22cb693889
commit ee651c3cd3
5 changed files with 42 additions and 97 deletions
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6
src/clang.zig
View File

@ -476,12 +476,6 @@ pub const FieldDecl = opaque {
pub const isBitField = ZigClangFieldDecl_isBitField;
extern fn ZigClangFieldDecl_isBitField(*const FieldDecl) bool;
pub const getBitWidthValue = ZigClangFieldDecl_getBitWidthValue;
extern fn ZigClangFieldDecl_getBitWidthValue(*const FieldDecl, *const ASTContext) c_uint;
pub const isZeroLengthBitField = ZigClangFieldDecl_isZeroLengthBitField;
extern fn ZigClangFieldDecl_isZeroLengthBitField(*const FieldDecl, *const ASTContext) bool;
pub const getType = ZigClangFieldDecl_getType;
extern fn ZigClangFieldDecl_getType(*const FieldDecl) QualType;

65
src/translate_c.zig
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@ -1085,15 +1085,17 @@ fn transRecordDecl(c: *Context, scope: *Scope, record_decl: *const clang.RecordD
const layout = record_def.getASTRecordLayout(c.clang_context);
const record_alignment = layout.getAlignment();
var record_bitfield_count: u32 = 0;
var bits_unused: i32 = 0;
var bits_type: clang.BuiltinTypeKind = clang.BuiltinTypeKind.Void;
while (it.neq(end_it)) : (it = it.next()) {
const field_decl = it.deref();
const field_loc = field_decl.getLocation();
const field_qt = field_decl.getType();
if (field_decl.isBitField()) {
try c.opaque_demotes.put(c.gpa, @ptrToInt(record_decl.getCanonicalDecl()), {});
try warn(c, scope, field_loc, "{s} demoted to opaque type - has bitfield", .{container_kind_name});
break :blk Tag.opaque_literal.init();
}
var is_anon = false;
var field_name = try c.str(@ptrCast(*const clang.NamedDecl, field_decl).getName_bytes_begin());
if (field_decl.isAnonymousStructOrUnion() or field_name.len == 0) {
@ -1123,53 +1125,6 @@ fn transRecordDecl(c: *Context, scope: *Scope, record_decl: *const clang.RecordD
else => |e| return e,
};
if (field_decl.isBitField()) {
var this_field_width = @intCast(i32, field_decl.getBitWidthValue(c.clang_context));
// are we starting new bitfield?
if (bits_unused <= 0) {
const size_map = std.ComptimeStringMap(u16, .{ .{ "u8", 8 }, .{ "c_ushort", 16 }, .{ "u16", 16 }, .{ "u32", 32 }, .{ "c_uint", 32 }, .{ "c_ulong", 32 }, .{ "c_ulonglong", 64 }, .{ "u64", 64 } });
bits_type = @ptrCast(*const clang.BuiltinType, field_qt.getTypePtr()).getKind();
var field_width = field_type.castTag(.type).?.*.data; // we just set it 10 lines back. this should not fail.
if (size_map.get(field_width)) |sz| {
bits_unused = @intCast(i32, sz) - this_field_width;
field_name = try std.fmt.allocPrint(c.arena, "bitfield{d}", .{record_bitfield_count});
record_bitfield_count += 1;
} else {
try warn(c, scope, field_loc, "{s} demoted to opaque type - bitfield type not unsigned or unknown. type:{s} ", .{ container_kind_name, field_width });
break :blk Tag.opaque_literal.init();
}
} else {
var this_type = @ptrCast(*const clang.BuiltinType, field_qt.getTypePtr()).getKind();
if (field_decl.isZeroLengthBitField(c.clang_context)) {
try warn(c, scope, field_loc, "{s} demoted to opaque type - bitfield with zero size not supported", .{container_kind_name});
break :blk Tag.opaque_literal.init();
} else if (bits_type != this_type) {
try warn(c, scope, field_loc, "{s} demoted to opaque type - bitfield type changed in the middle of bitfield was;{s} is:{s}", .{ container_kind_name, @tagName(bits_type), @tagName(this_type) });
break :blk Tag.opaque_literal.init();
} else {
// next
bits_unused -= this_field_width;
if (bits_unused < 0) {
try warn(c, scope, field_loc, "{s} demoted to opaque type - bitfield overrun type size not supported", .{container_kind_name});
break :blk Tag.opaque_literal.init();
}
}
continue; // free the field_type? tag is alloc'd
}
} else {
if (bits_unused >= 8) {
// if they didn't add a "reserved:n" at the end, and the # of bits used is more than 1 byte of their requested size,
// the layout is to compiler specific.
try warn(c, scope, field_loc, "{s} demoted to opaque type - less bits used than field size. unused bit count:{d}", .{ container_kind_name, bits_unused });
break :blk Tag.opaque_literal.init();
}
bits_unused = 0;
}
const alignment = if (has_flexible_array and field_decl.getFieldIndex() == 0)
@intCast(c_uint, record_alignment)
else
@ -1185,10 +1140,6 @@ fn transRecordDecl(c: *Context, scope: *Scope, record_decl: *const clang.RecordD
.alignment = alignment,
});
}
if (bits_unused >= 8) { // one last check if the last field was a bitfield
try warn(c, scope, record_loc, "{s} demoted to opaque type - less bits used than field size. unused bit count:{d}", .{ container_kind_name, bits_unused });
break :blk Tag.opaque_literal.init();
}
const record_payload = try c.arena.create(ast.Payload.Record);
record_payload.* = .{
@ -2625,9 +2576,7 @@ fn transInitListExprRecord(
continue;
}
if (init_i >= init_count) {
return fail(c, error.UnsupportedTranslation, loc, "init list longer fields in record. Record has bitfield?", .{});
}
assert(init_i < init_count);
const elem_expr = expr.getInit(init_i);
init_i += 1;

12
src/zig_clang.cpp
View File

@ -3335,18 +3335,6 @@ bool ZigClangFieldDecl_isBitField(const struct ZigClangFieldDecl *self) {
return casted->isBitField();
}
unsigned ZigClangFieldDecl_getBitWidthValue( const struct ZigClangFieldDecl *self, const ZigClangASTContext *ctx) {
auto casted = reinterpret_cast<const clang::FieldDecl *>(self);
auto casted_ctx = const_cast<clang::ASTContext *>(reinterpret_cast<const clang::ASTContext *>(ctx));
return casted->getBitWidthValue(*casted_ctx);
}
bool ZigClangFieldDecl_isZeroLengthBitField( ZigClangFieldDecl *self, const ZigClangASTContext *ctx) {
auto casted = reinterpret_cast<const clang::FieldDecl *>(self);
auto casted_ctx = const_cast<clang::ASTContext *>(reinterpret_cast<const clang::ASTContext *>(ctx));
return casted->isZeroLengthBitField(*casted_ctx);
}
bool ZigClangFieldDecl_isAnonymousStructOrUnion(const ZigClangFieldDecl *field_decl) {
return reinterpret_cast<const clang::FieldDecl*>(field_decl)->isAnonymousStructOrUnion();
}

2
src/zig_clang.h
View File

@ -1407,8 +1407,6 @@ ZIG_EXTERN_C struct ZigClangSourceLocation ZigClangMacroDefinitionRecord_getSour
ZIG_EXTERN_C struct ZigClangSourceLocation ZigClangMacroDefinitionRecord_getSourceRange_getEnd(const struct ZigClangMacroDefinitionRecord *);
ZIG_EXTERN_C bool ZigClangFieldDecl_isBitField(const struct ZigClangFieldDecl *);
ZIG_EXTERN_C unsigned ZigClangFieldDecl_getBitWidthValue( const struct ZigClangFieldDecl *, const ZigClangASTContext *);
ZIG_EXTERN_C bool ZigClangFieldDecl_isZeroLengthBitField( ZigClangFieldDecl *, const ZigClangASTContext *);
ZIG_EXTERN_C bool ZigClangFieldDecl_isAnonymousStructOrUnion(const ZigClangFieldDecl *);
ZIG_EXTERN_C struct ZigClangQualType ZigClangFieldDecl_getType(const struct ZigClangFieldDecl *);
ZIG_EXTERN_C struct ZigClangSourceLocation ZigClangFieldDecl_getLocation(const struct ZigClangFieldDecl *);

54
test/translate_c.zig
View File

@ -915,6 +915,21 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
\\};
});
cases.add("pointer to struct demoted to opaque due to bit fields",
\\struct Foo {
\\ unsigned int: 1;
\\};
\\struct Bar {
\\ struct Foo *foo;
\\};
, &[_][]const u8{
\\pub const struct_Foo = opaque {};
,
\\pub const struct_Bar = extern struct {
\\ foo: ?*struct_Foo,
\\};
});
cases.add("macro with left shift",
\\#define REDISMODULE_READ (1<<0)
, &[_][]const u8{
@ -3562,33 +3577,34 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
\\}
});
cases.add("function that dereferences bitfield works",
cases.add("Demote function that initializes opaque struct",
\\struct my_struct {
\\ unsigned a: 15;
\\ unsigned: 2;
\\ unsigned b: 15;
\\};
\\void initialize(void) {
\\ struct my_struct S = {.a = 1, .b = 2};
\\}
, &[_][]const u8{
\\warning: cannot initialize opaque type
,
\\warning: unable to translate function, demoted to extern
\\pub extern fn initialize() void;
});
cases.add("Demote function that dereferences opaque type",
\\struct my_struct {
\\ unsigned a: 1;
\\ unsigned b: 28;
\\};
\\void deref(struct my_struct *s) {
\\ *s;
\\}
, &[_][]const u8{
\\pub const struct_my_struct = extern struct {
\\ bitfield0: c_uint,
\\warning: cannot dereference opaque type
,
\\pub export fn deref(arg_s: ?*struct_my_struct) void {
\\ var s = arg_s;
\\ _ = s.*;
\\}
});
cases.add("bitfield don't cover requedted space",
\\struct inner {
\\ unsigned a: 1;
\\ char after;
\\};
, &[_][]const u8{
\\less bits used than field size.
,
\\pub const struct_inner = opaque {};
\\warning: unable to translate function, demoted to extern
\\pub extern fn deref(arg_s: ?*struct_my_struct) void;
});
cases.add("Function prototype declared within function",