static int EqualSymTables (SymTable* Tab1, SymTable* Tab2)
/* Compare two symbol tables. Return 1 if they are equal and 0 otherwise */
{
/* Compare the parameter lists */
SymEntry* Sym1 = Tab1->SymHead;
SymEntry* Sym2 = Tab2->SymHead;
/* Compare the fields */
while (Sym1 && Sym2) {
/* Compare the names of this field */
if (!HasAnonName (Sym1) || !HasAnonName (Sym2)) {
if (strcmp (Sym1->Name, Sym2->Name) != 0) {
/* Names are not identical */
return 0;
}
}
/* Compare the types of this field */
if (TypeCmp (Sym1->Type, Sym2->Type) < TC_EQUAL) {
/* Field types not equal */
return 0;
}
/* Get the pointers to the next fields */
Sym1 = Sym1->NextSym;
Sym2 = Sym2->NextSym;
}
/* Check both pointers against NULL to compare the field count */
return (Sym1 == 0 && Sym2 == 0);
}
static int EqualFuncParams (const FuncDesc* F1, const FuncDesc* F2)
/* Compare two function symbol tables regarding function parameters. Return 1
** if they are equal and 0 otherwise.
*/
{
/* Get the symbol tables */
const SymTable* Tab1 = F1->SymTab;
const SymTable* Tab2 = F2->SymTab;
/* Compare the parameter lists */
const SymEntry* Sym1 = Tab1->SymHead;
const SymEntry* Sym2 = Tab2->SymHead;
/* Compare the fields */
while (Sym1 && (Sym1->Flags & SC_PARAM) && Sym2 && (Sym2->Flags & SC_PARAM)) {
/* Get the symbol types */
Type* Type1 = Sym1->Type;
Type* Type2 = Sym2->Type;
/* If either of both functions is old style, apply the default
** promotions to the parameter type.
*/
if (F1->Flags & FD_OLDSTYLE) {
if (IsClassInt (Type1)) {
Type1 = IntPromotion (Type1);
}
}
if (F2->Flags & FD_OLDSTYLE) {
if (IsClassInt (Type2)) {
Type2 = IntPromotion (Type2);
}
}
/* Compare this field */
if (TypeCmp (Type1, Type2) < TC_EQUAL) {
/* Field types not equal */
return 0;
}
/* Get the pointers to the next fields */
Sym1 = Sym1->NextSym;
Sym2 = Sym2->NextSym;
}
/* Check both pointers against NULL or a non parameter to compare the
** field count
*/
return (Sym1 == 0 || (Sym1->Flags & SC_PARAM) == 0) &&
(Sym2 == 0 || (Sym2->Flags & SC_PARAM) == 0);
}
static void AliasAttr (const Declaration* D, DeclAttr* A)
/* Handle the "alias" attribute */
{
SymEntry* Sym;
/* Comma expected */
ConsumeComma ();
/* The next identifier is the name of the alias symbol */
if (CurTok.Tok != TOK_IDENT) {
Error ("Identifier expected");
return;
}
/* Lookup the symbol for this name, it must exist */
Sym = FindSym (CurTok.Ident);
if (Sym == 0) {
Error ("Unknown identifier: `%s'", CurTok.Ident);
NextToken ();
return;
}
/* Since we have the symbol entry now, skip the name */
NextToken ();
/* Check if the types of the symbols are identical */
if (TypeCmp (D->Type, Sym->Type) < TC_EQUAL) {
/* Types are not identical */
Error ("Incompatible types");
return;
}
/* Attribute is verified, set the stuff in the attribute description */
A->AttrType = atAlias;
A->V.Sym = Sym;
}
SymEntry* AddGlobalSym (const char* Name, const Type* T, unsigned Flags)
/* Add an external or global symbol to the symbol table and return the entry */
{
/* There is some special handling for functions, so check if it is one */
int IsFunc = IsTypeFunc (T);
/* Functions must be inserted in the global symbol table */
SymTable* Tab = IsFunc? SymTab0 : SymTab;
/* Do we have an entry with this name already? */
SymEntry* Entry = FindSymInTable (Tab, Name, HashStr (Name));
if (Entry) {
Type* EType;
/* We have a symbol with this name already */
if (Entry->Flags & SC_TYPE) {
Error ("Multiple definition for `%s'", Name);
return Entry;
}
/* Get the type string of the existing symbol */
EType = Entry->Type;
/* If we are handling arrays, the old entry or the new entry may be an
** incomplete declaration. Accept this, and if the exsting entry is
** incomplete, complete it.
*/
if (IsTypeArray (T) && IsTypeArray (EType)) {
/* Get the array sizes */
long Size = GetElementCount (T);
long ESize = GetElementCount (EType);
if ((Size != UNSPECIFIED && ESize != UNSPECIFIED && Size != ESize) ||
TypeCmp (T + 1, EType + 1) < TC_EQUAL) {
/* Types not identical: Conflicting types */
Error ("Conflicting types for `%s'", Name);
return Entry;
} else {
/* Check if we have a size in the existing definition */
if (ESize == UNSPECIFIED) {
/* Existing, size not given, use size from new def */
SetElementCount (EType, Size);
}
}
} else {
/* New type must be identical */
if (TypeCmp (EType, T) < TC_EQUAL) {
Error ("Conflicting types for `%s'", Name);
return Entry;
}
/* In case of a function, use the new type descriptor, since it
** contains pointers to the new symbol tables that are needed if
** an actual function definition follows. Be sure not to use the
** new descriptor if it contains a function declaration with an
** empty parameter list.
*/
if (IsFunc) {
/* Get the function descriptor from the new type */
FuncDesc* F = GetFuncDesc (T);
/* Use this new function descriptor if it doesn't contain
** an empty parameter list.
*/
if ((F->Flags & FD_EMPTY) == 0) {
Entry->V.F.Func = F;
SetFuncDesc (EType, F);
}
}
}
/* Add the new flags */
Entry->Flags |= Flags;
} else {
/* Create a new entry */
Entry = NewSymEntry (Name, Flags);
/* Set the symbol attributes */
Entry->Type = TypeDup (T);
/* If this is a function, set the function descriptor and clear
** additional fields.
*/
if (IsFunc) {
Entry->V.F.Func = GetFuncDesc (Entry->Type);
Entry->V.F.Seg = 0;
}
/* Add the assembler name of the symbol */
SymSetAsmName (Entry);
/* Add the entry to the symbol table */
AddSymEntry (Tab, Entry);
}
/* Return the entry */
return Entry;
}
