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Fix checking first member of union after zero size field

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Nick Treleaven 2024-09-24 16:20:05 +01:00 • committed by Nicholas Wilson
parent 5197836d45
commit da45058997
2 changed files with 14 additions and 7 deletions
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10
compiler/src/dmd/dstruct.d
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@ -233,8 +233,12 @@ extern (C++) class StructDeclaration : AggregateDeclaration
auto lastOffset = -1;
foreach (vd; fields)
{
// First skip zero sized fields
if (vd.type.size(vd.loc) == 0)
continue;
// only consider first sized member of an (anonymous) union
if (vd.overlapped && vd.offset == lastOffset && vd.type.size(vd.loc) != 0)
if (vd.overlapped && vd.offset == lastOffset)
continue;
lastOffset = vd.offset;
@ -246,10 +250,6 @@ extern (C++) class StructDeclaration : AggregateDeclaration
*/
continue;
// Zero size fields are zero initialized
if (vd.type.size(vd.loc) == 0)
continue;
// Examine init to see if it is all 0s.
auto exp = vd.getConstInitializer();
if (!exp || !_isZeroInit(exp))

11
compiler/test/compilable/isZeroInit.d
View file

@ -103,7 +103,6 @@ union U
float x = 0;
float y;
}
static assert(__traits(isZeroInit, U));
union U2
@ -111,5 +110,13 @@ union U2
float x;
int y;
}
static assert(!__traits(isZeroInit, U2));
struct S8 {
int[0] dummy; // same offset as anon union, but doesn't overlap; should be ignored anyway for zero-init check
union {
float f; // is the first member of the anon union and must be checked
int i;
}
}
static assert(!__traits(isZeroInit, S8));