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ImportC: implement bitfields for StructLiteralExpression

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Walter Bright 2021-08-20 02:27:04 -07:00 • committed by The Dlang Bot
parent 1f4133bc62
commit 61103da39c
3 changed files with 85 additions and 5 deletions
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28
src/dmd/declaration.d
View file

@ -1319,11 +1319,31 @@ extern (C++) class VarDeclaration : Declaration
final bool isOverlappedWith(VarDeclaration v)
{
const vsz = v.type.size();
const tsz = type.size();
auto vsz = v.type.size();
auto tsz = type.size();
assert(vsz != SIZE_INVALID && tsz != SIZE_INVALID);
return offset < v.offset + vsz &&
v.offset < offset + tsz;
auto off = offset * 8;
auto voff = v.offset * 8;
if (auto bf = isBitFieldDeclaration())
{
off += bf.bitOffset;
tsz = bf.fieldWidth;
}
else
tsz *= 8;
if (auto bf = v.isBitFieldDeclaration())
{
voff += bf.bitOffset;
vsz = bf.fieldWidth;
}
else
vsz *= 8;
return off < voff + vsz &&
voff < off + tsz;
}
override final bool hasPointers()

22
src/dmd/e2ir.d
View file

@ -6227,6 +6227,7 @@ elem *toElemStructLit(StructLiteralExp sle, IRState *irs, TOK op, Symbol *sym, b
// CTFE may fill the hidden pointer by NullExp.
{
VarDeclaration vbf;
foreach (i, el; *sle.elements)
{
if (!el)
@ -6270,6 +6271,27 @@ elem *toElemStructLit(StructLiteralExp sle, IRState *irs, TOK op, Symbol *sym, b
e1 = el_una(OPind, ty, e1);
if (tybasic(ty) == TYstruct)
e1.ET = Type_toCtype(v.type);
if (auto bf = v.isBitFieldDeclaration())
{
if (!vbf || vbf.offset + vbf.type.size() <= v.offset)
{
/* Initialize entire location the bitfield is in
* ep = (ep & ((1 << bf.fieldWidth) - 1)) << bf.bitOffset
*/
tym_t e1ty = e1.Ety;
auto ex = el_bin(OPand, e1ty, ep, el_long(e1ty, (1L << bf.fieldWidth) - 1));
ep = el_bin(OPshl, e1ty, ex, el_long(e1ty, bf.bitOffset));
vbf = v;
}
else
{
// Insert special bitfield operator
auto mos = el_long(TYuint, bf.fieldWidth * 256 + bf.bitOffset);
e1 = el_bin(OPbit, e1.Ety, e1, mos);
}
}
else
vbf = null;
e1 = elAssign(e1, ep, v.type, e1.ET);
}
e = el_combine(e, e1);

40
test/runnable/bitfields.c
View file

@ -8,7 +8,7 @@ struct S
_Static_assert(sizeof(struct S) == 4, "in");
int main()
void test1()
{
struct S s;
s.a = 3;
@ -24,6 +24,44 @@ int main()
printf("error %d\n", s.b);
exit(1);
}
}
/******************************************/
struct S2
{
unsigned a:2, b:4;
};
struct S2 foo()
{
struct S2 s = { 7, 8 }; // test struct literal expressions
return s;
}
void test2()
{
struct S2 s = foo();
if (s.a != 3)
{
printf("error %d\n", s.a);
exit(1);
}
if (s.b != 8)
{
printf("error %d\n", s.b);
exit(1);
}
}
/******************************************/
int main()
{
test1();
test2();
return 0;
}