gbdev/rgbds
1
0
Fork 0
mirror of https://github.com/gbdev/rgbds.git synced 2025-11-20 10:12:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

Make sure that parsed subexpressions are fully defined

Browse Source 
We were not initializing some expressions, and they were using
the values of the previous expressions instead. This just so
happened to not crash the tests, and to sometimes even give valid
results (although `BANK()` of a non-label symbol being $4B4E4142,
the ASCII balue of "BANK", was something we missed).
This commit is contained in:
Rangi42
2024-03-06 15:53:01 -05:00
parent f419f206e5
commit 75105016f7
3 changed files with 11 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
src/asm/rpn.cpp
View File

@@ -24,6 +24,7 @@
// Init a RPN expression
static void initExpression(Expression &expr) {
expr.val = 0;
expr.reason = nullptr;
expr.isKnown = true;
expr.isSymbol = false;
@@ -68,13 +69,14 @@ void rpn_Number(Expression &expr, uint32_t val) {
}
void rpn_Symbol(Expression &expr, char const *symName) {
initExpression(expr);
Symbol *sym = sym_FindScopedSymbol(symName);
if (sym_IsPC(sym) && !sect_GetSymbolSection()) {
error("PC has no value outside a section\n");
rpn_Number(expr, 0);
expr.val = 0;
} else if (!sym || !sym->isConstant()) {
initExpression(expr);
expr.isSymbol = true;
if (sym_IsPC(sym))
@@ -89,7 +91,7 @@ void rpn_Symbol(Expression &expr, char const *symName) {
*ptr++ = RPN_SYM;
memcpy(ptr, sym->name, nameLen);
} else {
rpn_Number(expr, sym_GetConstantValue(symName));
expr.val = sym_GetConstantValue(symName);
}
}
@@ -120,6 +122,7 @@ void rpn_BankSymbol(Expression &expr, char const *symName) {
initExpression(expr);
if (sym && !sym->isLabel()) {
error("BANK argument must be a label\n");
expr.val = 1;
} else {
sym = sym_Ref(symName);
assert(sym); // If the symbol didn't exist, it should have been created
@@ -345,13 +348,13 @@ static int32_t tryConstMask(Expression const &lhs, Expression const &rhs) {
void rpn_BinaryOp(
enum RPNCommand op, Expression &expr, const Expression &src1, const Expression &src2
) {
initExpression(expr);
expr.isSymbol = false;
int32_t constMaskVal;
// First, check if the expression is known
expr.isKnown = src1.isKnown && src2.isKnown;
if (expr.isKnown) {
initExpression(expr); // Init the expression to something sane
// If both expressions are known, just compute the value
uint32_t uleft = src1.val, uright = src2.val;