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Correct alignment of structure members

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git-svn-id: http://picoc.googlecode.com/svn/trunk@341 21eae674-98b7-11dd-bd71-f92a316d2d60
This commit is contained in:
zik.saleeba 2009-10-11 18:55:16 +00:00
parent 196331d6ba
commit 0d83e26880
1 changed files with 21 additions and 5 deletions
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26
type.c
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@ -78,7 +78,7 @@ int TypeSizeValue(struct Value *Val)
else if (Val->Typ->Base != TypeArray) else if (Val->Typ->Base != TypeArray)
return Val->Typ->Sizeof; return Val->Typ->Sizeof;
else else
return sizeof(struct ArrayValue) + Val->Typ->FromType->Sizeof * Val->Val->Array.Size; return sizeof(struct ArrayValue) + Val->Typ->FromType->Sizeof * Val->Typ->ArraySize;
} }
/* the last accessible offset of a value */ /* the last accessible offset of a value */
@ -101,6 +101,15 @@ int TypeSize(struct ValueType *Typ, int ArraySize, int Compact)
return sizeof(struct ArrayValue) + Typ->FromType->Sizeof * ArraySize; return sizeof(struct ArrayValue) + Typ->FromType->Sizeof * ArraySize;
} }
/* memory used by the base (non-array) type of a type. This is used for alignment. */
int TypeSizeAlignment(struct ValueType *Typ)
{
if (Typ->Base == TypeArray)
return sizeof(unsigned int);
else
return Typ->Sizeof;
}
/* add a base type */ /* add a base type */
void TypeAddBaseType(struct ValueType *TypeNode, enum BaseType Base, int Sizeof) void TypeAddBaseType(struct ValueType *TypeNode, enum BaseType Base, int Sizeof)
{ {
@ -179,6 +188,7 @@ void TypeParseStruct(struct ParseState *Parser, struct ValueType **Typ, int IsSt
char *MemberIdentifier; char *MemberIdentifier;
struct Value *MemberValue; struct Value *MemberValue;
enum LexToken Token; enum LexToken Token;
int AlignBoundary;
if (TopStackFrame != NULL) if (TopStackFrame != NULL)
ProgramFail(Parser, "struct/union definitions can only be globals"); ProgramFail(Parser, "struct/union definitions can only be globals");
@ -210,15 +220,21 @@ void TypeParseStruct(struct ParseState *Parser, struct ValueType **Typ, int IsSt
MemberValue = VariableAllocValueAndData(Parser, sizeof(int), FALSE, NULL, TRUE); MemberValue = VariableAllocValueAndData(Parser, sizeof(int), FALSE, NULL, TRUE);
MemberValue->Typ = MemberType; MemberValue->Typ = MemberType;
if (IsStruct) if (IsStruct)
{ /* allocate this member's location in the struct */ {
/* allocate this member's location in the struct */
AlignBoundary = TypeSizeAlignment(MemberValue->Typ);
if (((*Typ)->Sizeof & (AlignBoundary-1)) != 0)
(*Typ)->Sizeof += AlignBoundary - ((*Typ)->Sizeof & (AlignBoundary-1));
MemberValue->Val->Integer = (*Typ)->Sizeof; MemberValue->Val->Integer = (*Typ)->Sizeof;
(*Typ)->Sizeof += MemberValue->Typ->Sizeof; (*Typ)->Sizeof += TypeSizeValue(MemberValue);
} }
else else
{ /* union members always start at 0, make sure it's big enough to hold the largest member */ {
/* union members always start at 0, make sure it's big enough to hold the largest member */
MemberValue->Val->Integer = 0; MemberValue->Val->Integer = 0;
if (MemberValue->Typ->Sizeof > (*Typ)->Sizeof) if (MemberValue->Typ->Sizeof > (*Typ)->Sizeof)
(*Typ)->Sizeof = MemberValue->Typ->Sizeof; (*Typ)->Sizeof = TypeSizeValue(MemberValue);
} }
if (!TableSet((*Typ)->Members, MemberIdentifier, MemberValue)) if (!TableSet((*Typ)->Members, MemberIdentifier, MemberValue))