virtual void VisitExpr( const SymbolicExpr& v)
{
SymbolicVal in1, fr1;
bool _hasfrac = hasfrac;
SymbolicExpr::OpdIterator opds = v.GetOpdIterator();
for ( ; !opds.ReachEnd(); ++opds) {
if (operator()(v.Term2Val(*opds), inp, frp)) {
_hasfrac = true;
break;
}
}
if (opds.ReachEnd()) {
if (inp != 0) *inp = v;
}
else {
if (inp == 0 && frp == 0)
return;
SymbolicExpr* inv = (inp == 0)? 0 : v.DistributeExpr(SYMOP_NIL, SymbolicVal());
SymbolicExpr* frv = (frp == 0)? 0 : v.DistributeExpr(SYMOP_NIL, SymbolicVal());
SymbolicExpr::OpdIterator opd1 = v.GetOpdIterator();
for ( ; opd1 != opds ; ++opd1) {
if (inv != 0)
inv->AddOpd(*opd1);
if (frv != 0)
frv->AddOpd(*opd1);
}
if (inv != 0)
inv->ApplyOpd(*inp);
if (frv != 0)
frv->ApplyOpd(*frp);
for (++opd1; !opd1.ReachEnd(); ++opd1) {
SymbolicVal cur = v.Term2Val(*opd1);
if (operator()(cur, inp, frp)) {
if (inv != 0)
inv->ApplyOpd(*inp);
if (frv != 0)
frv->ApplyOpd(*frp);
}
else {
if (inv != 0)
inv->AddOpd(*opd1);
if (frv != 0)
frv->AddOpd(*opd1);
}
}
if (inp != 0)
*inp = GetExprVal(inv);
if (frp != 0)
*frp = GetExprVal(frv);
}
hasfrac = _hasfrac;
}
int IsBSSType (Segment* S)
/* Check if the given segment is a BSS style segment, that is, it does not
** contain non-zero data.
*/
{
/* Loop over all sections */
unsigned I;
for (I = 0; I < CollCount (&S->Sections); ++I) {
/* Get the next section */
Section* Sec = CollAtUnchecked (&S->Sections, I);
/* Loop over all fragments */
Fragment* F = Sec->FragRoot;
while (F) {
if (F->Type == FRAG_LITERAL) {
unsigned char* Data = F->LitBuf;
unsigned long Count = F->Size;
while (Count--) {
if (*Data++ != 0) {
return 0;
}
}
} else if (F->Type == FRAG_EXPR || F->Type == FRAG_SEXPR) {
if (GetExprVal (F->Expr) != 0) {
return 0;
}
}
F = F->Next;
}
}
return 1;
}
long GetExportVal (const Export* E)
/* Get the value of this export */
{
if (E->Expr == 0) {
/* OOPS */
Internal ("`%s' is an undefined external", GetString (E->Name));
}
return GetExprVal (E->Expr);
}
void CheckAssertions (void)
/* Check all assertions */
{
unsigned I;
/* Walk over all assertions */
for (I = 0; I < CollCount (&Assertions); ++I) {
const LineInfo* LI;
const char* Module;
unsigned Line;
/* Get the assertion */
Assertion* A = CollAtUnchecked (&Assertions, I);
/* Ignore assertions that shouldn't be handled at link time */
if (!AssertAtLinkTime (A->Action)) {
continue;
}
/* Retrieve the relevant line info for this assertion */
LI = CollConstAt (&A->LineInfos, 0);
/* Get file name and line number from the source */
Module = GetSourceName (LI);
Line = GetSourceLine (LI);
/* If the expression is not constant, we're not able to handle it */
if (!IsConstExpr (A->Expr)) {
Warning ("Cannot evaluate assertion in module `%s', line %u",
Module, Line);
} else if (GetExprVal (A->Expr) == 0) {
/* Assertion failed */
const char* Message = GetString (A->Msg);
switch (A->Action) {
case ASSERT_ACT_WARN:
case ASSERT_ACT_LDWARN:
Warning ("%s(%u): %s", Module, Line, Message);
break;
case ASSERT_ACT_ERROR:
case ASSERT_ACT_LDERROR:
Error ("%s(%u): %s", Module, Line, Message);
break;
default:
Internal ("Invalid assertion action (%u) in module `%s', "
"line %u (file corrupt?)",
A->Action, Module, Line);
break;
}
}
}
}
unsigned SegWriteConstExpr (FILE* F, ExprNode* E, int Signed, unsigned Size)
/* Write a supposedly constant expression to the target file. Do a range
** check and return one of the SEG_EXPR_xxx codes.
*/
{
static const unsigned long U_Hi[4] = {
0x000000FFUL, 0x0000FFFFUL, 0x00FFFFFFUL, 0xFFFFFFFFUL
};
static const long S_Hi[4] = {
0x0000007FL, 0x00007FFFL, 0x007FFFFFL, 0x7FFFFFFFL
};
static const long S_Lo[4] = {
~0x0000007FL, ~0x00007FFFL, ~0x007FFFFFL, ~0x7FFFFFFFL
};
/* Get the expression value */
long Val = GetExprVal (E);
/* Check the size */
CHECK (Size >= 1 && Size <= 4);
/* Check for a range error */
if (Signed) {
if (Val > S_Hi[Size-1] || Val < S_Lo[Size-1]) {
/* Range error */
return SEG_EXPR_RANGE_ERROR;
}
} else {
if (((unsigned long)Val) > U_Hi[Size-1]) {
/* Range error */
return SEG_EXPR_RANGE_ERROR;
}
}
/* Write the value to the file */
WriteVal (F, Val, Size);
/* Success */
return SEG_EXPR_OK;
}
int IsConstExpr (ExprNode* Root)
/* Return true if the given expression is a constant expression, that is, one
* with no references to external symbols.
*/
{
int Const;
Export* E;
Section* S;
MemoryArea* M;
if (EXPR_IS_LEAF (Root->Op)) {
switch (Root->Op) {
case EXPR_LITERAL:
return 1;
case EXPR_SYMBOL:
/* Get the referenced export */
E = GetExprExport (Root);
/* If this export has a mark set, we've already encountered it.
* This means that the export is used to define it's own value,
* which in turn means, that we have a circular reference.
*/
if (ExportHasMark (E)) {
CircularRefError (E);
Const = 0;
} else {
MarkExport (E);
Const = IsConstExport (E);
UnmarkExport (E);
}
return Const;
case EXPR_SECTION:
/* A section expression is const if the segment it is in is
* not relocatable and already placed.
*/
S = GetExprSection (Root);
M = S->Seg->MemArea;
return M != 0 && (M->Flags & MF_PLACED) != 0 && !M->Relocatable;
case EXPR_SEGMENT:
/* A segment is const if it is not relocatable and placed */
M = Root->V.Seg->MemArea;
return M != 0 && (M->Flags & MF_PLACED) != 0 && !M->Relocatable;
case EXPR_MEMAREA:
/* A memory area is const if it is not relocatable and placed */
return !Root->V.Mem->Relocatable &&
(Root->V.Mem->Flags & MF_PLACED);
default:
/* Anything else is not const */
return 0;
}
} else if (EXPR_IS_UNARY (Root->Op)) {
SegExprDesc D;
/* Special handling for the BANK pseudo function */
switch (Root->Op) {
case EXPR_BANK:
/* Get segment references for the expression */
GetSegExprVal (Root->Left, &D);
/* The expression is const if the expression contains exactly
* one segment that is assigned to a memory area which has a
* bank attribute that is constant.
*/
return (D.TooComplex == 0 &&
D.Seg != 0 &&
D.Seg->MemArea != 0 &&
D.Seg->MemArea->BankExpr != 0 &&
IsConstExpr (D.Seg->MemArea->BankExpr));
default:
/* All others handled normal */
return IsConstExpr (Root->Left);
}
} else {
/* We must handle shortcut boolean expressions here */
switch (Root->Op) {
case EXPR_BOOLAND:
if (IsConstExpr (Root->Left)) {
/* lhs is const, if it is zero, don't eval right */
if (GetExprVal (Root->Left) == 0) {
return 1;
} else {
return IsConstExpr (Root->Right);
}
} else {
/* lhs not const --> tree not const */
return 0;
}
break;
case EXPR_BOOLOR:
if (IsConstExpr (Root->Left)) {
/* lhs is const, if it is not zero, don't eval right */
if (GetExprVal (Root->Left) != 0) {
return 1;
} else {
return IsConstExpr (Root->Right);
}
} else {
/* lhs not const --> tree not const */
return 0;
}
break;
default:
/* All others are handled normal */
return IsConstExpr (Root->Left) && IsConstExpr (Root->Right);
}
}
}
long GetExprVal (ExprNode* Expr)
/* Get the value of a constant expression */
{
long Right;
long Left;
long Val;
Section* S;
Export* E;
SegExprDesc D;
switch (Expr->Op) {
case EXPR_LITERAL:
return Expr->V.IVal;
case EXPR_SYMBOL:
/* Get the referenced export */
E = GetExprExport (Expr);
/* If this export has a mark set, we've already encountered it.
* This means that the export is used to define it's own value,
* which in turn means, that we have a circular reference.
*/
if (ExportHasMark (E)) {
CircularRefError (E);
Val = 0;
} else {
MarkExport (E);
Val = GetExportVal (E);
UnmarkExport (E);
}
return Val;
case EXPR_SECTION:
S = GetExprSection (Expr);
return S->Offs + S->Seg->PC;
case EXPR_SEGMENT:
return Expr->V.Seg->PC;
case EXPR_MEMAREA:
return Expr->V.Mem->Start;
case EXPR_PLUS:
return GetExprVal (Expr->Left) + GetExprVal (Expr->Right);
case EXPR_MINUS:
return GetExprVal (Expr->Left) - GetExprVal (Expr->Right);
case EXPR_MUL:
return GetExprVal (Expr->Left) * GetExprVal (Expr->Right);
case EXPR_DIV:
Left = GetExprVal (Expr->Left);
Right = GetExprVal (Expr->Right);
if (Right == 0) {
Error ("Division by zero");
}
return Left / Right;
case EXPR_MOD:
Left = GetExprVal (Expr->Left);
Right = GetExprVal (Expr->Right);
if (Right == 0) {
Error ("Modulo operation with zero");
}
return Left % Right;
case EXPR_OR:
return GetExprVal (Expr->Left) | GetExprVal (Expr->Right);
case EXPR_XOR:
return GetExprVal (Expr->Left) ^ GetExprVal (Expr->Right);
case EXPR_AND:
return GetExprVal (Expr->Left) & GetExprVal (Expr->Right);
case EXPR_SHL:
return GetExprVal (Expr->Left) << GetExprVal (Expr->Right);
case EXPR_SHR:
return GetExprVal (Expr->Left) >> GetExprVal (Expr->Right);
case EXPR_EQ:
return (GetExprVal (Expr->Left) == GetExprVal (Expr->Right));
case EXPR_NE:
return (GetExprVal (Expr->Left) != GetExprVal (Expr->Right));
case EXPR_LT:
return (GetExprVal (Expr->Left) < GetExprVal (Expr->Right));
case EXPR_GT:
return (GetExprVal (Expr->Left) > GetExprVal (Expr->Right));
case EXPR_LE:
return (GetExprVal (Expr->Left) <= GetExprVal (Expr->Right));
case EXPR_GE:
return (GetExprVal (Expr->Left) >= GetExprVal (Expr->Right));
case EXPR_BOOLAND:
return GetExprVal (Expr->Left) && GetExprVal (Expr->Right);
case EXPR_BOOLOR:
return GetExprVal (Expr->Left) || GetExprVal (Expr->Right);
case EXPR_BOOLXOR:
return (GetExprVal (Expr->Left) != 0) ^ (GetExprVal (Expr->Right) != 0);
case EXPR_MAX:
Left = GetExprVal (Expr->Left);
Right = GetExprVal (Expr->Right);
return (Left > Right)? Left : Right;
case EXPR_MIN:
Left = GetExprVal (Expr->Left);
Right = GetExprVal (Expr->Right);
return (Left < Right)? Left : Right;
case EXPR_UNARY_MINUS:
return -GetExprVal (Expr->Left);
case EXPR_NOT:
return ~GetExprVal (Expr->Left);
case EXPR_SWAP:
Left = GetExprVal (Expr->Left);
return ((Left >> 8) & 0x00FF) | ((Left << 8) & 0xFF00);
case EXPR_BOOLNOT:
return !GetExprVal (Expr->Left);
case EXPR_BANK:
GetSegExprVal (Expr->Left, &D);
if (D.TooComplex || D.Seg == 0) {
Error ("Argument for .BANK is not segment relative or too complex");
}
if (D.Seg->MemArea == 0) {
Error ("Segment `%s' is referenced by .BANK but "
"not assigned to a memory area",
GetString (D.Seg->Name));
}
if (D.Seg->MemArea->BankExpr == 0) {
Error ("Memory area `%s' is referenced by .BANK but "
"has no BANK attribute",
GetString (D.Seg->MemArea->Name));
}
return GetExprVal (D.Seg->MemArea->BankExpr);
case EXPR_BYTE0:
return GetExprVal (Expr->Left) & 0xFF;
case EXPR_BYTE1:
return (GetExprVal (Expr->Left) >> 8) & 0xFF;
case EXPR_BYTE2:
return (GetExprVal (Expr->Left) >> 16) & 0xFF;
case EXPR_BYTE3:
return (GetExprVal (Expr->Left) >> 24) & 0xFF;
case EXPR_WORD0:
return GetExprVal (Expr->Left) & 0xFFFF;
case EXPR_WORD1:
return (GetExprVal (Expr->Left) >> 16) & 0xFFFF;
case EXPR_FARADDR:
return GetExprVal (Expr->Left) & 0xFFFFFF;
case EXPR_DWORD:
return GetExprVal (Expr->Left) & 0xFFFFFFFF;
default:
Internal ("Unknown expression Op type: %u", Expr->Op);
/* NOTREACHED */
return 0;
}
}