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Use loops instead of tail calls and musttail

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gcc 15.2.1 20250813 complains "address of automatic variable can
escape to `musttail` call" from `-Wmaybe-musttail-local-addr`,
and guaranteeing tail-call optimization cross-platform is more
trouble than it's worth.
This commit is contained in:
Rangi42
2025-10-27 12:05:27 -04:00
parent 2519d1e698
commit df5162edca
3 changed files with 112 additions and 124 deletions
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67
src/asm/lexer.cpp
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@@ -716,45 +716,44 @@ int LexerState::peekCharAhead() {
static std::pair<Symbol const *, std::shared_ptr<std::string>> readInterpolation(size_t depth);
static int peek() {
int c = lexerState->peekChar();
for (;;) {
int c = lexerState->peekChar();
if (lexerState->expansionScanDistance > 0) {
return c;
}
++lexerState->expansionScanDistance; // Do not consider again
if (lexerState->disableExpansions) {
return c;
} else if (c == '\\') {
// If character is a backslash, check for a macro arg
++lexerState->expansionScanDistance;
if (!isMacroChar(lexerState->peekCharAhead())) {
if (lexerState->expansionScanDistance > 0) {
return c;
}
// If character is a macro arg char, do macro arg expansion
shiftChar();
if (std::shared_ptr<std::string> str = readMacroArg(); str) {
beginExpansion(str, std::nullopt);
++lexerState->expansionScanDistance; // Do not consider again
// Mark the entire macro arg expansion as "painted blue"
// so that macro args can't be recursive
// https://en.wikipedia.org/wiki/Painted_blue
lexerState->expansionScanDistance += str->length();
if (lexerState->disableExpansions) {
return c;
} else if (c == '\\') {
// If character is a backslash, check for a macro arg
++lexerState->expansionScanDistance;
if (!isMacroChar(lexerState->peekCharAhead())) {
return c;
}
// If character is a macro arg char, do macro arg expansion
shiftChar();
if (std::shared_ptr<std::string> str = readMacroArg(); str) {
beginExpansion(str, std::nullopt);
// Mark the entire macro arg expansion as "painted blue"
// so that macro args can't be recursive
// https://en.wikipedia.org/wiki/Painted_blue
lexerState->expansionScanDistance += str->length();
}
// Continue in the next iteration
} else if (c == '{') {
// If character is an open brace, do symbol interpolation
shiftChar();
if (auto interp = readInterpolation(0); interp.first && interp.second) {
beginExpansion(interp.second, interp.first->name);
}
// Continue in the next iteration
} else {
return c;
}
MUSTTAIL return peek();
} else if (c == '{') {
// If character is an open brace, do symbol interpolation
shiftChar();
if (auto interp = readInterpolation(0); interp.first && interp.second) {
beginExpansion(interp.second, interp.first->name);
}
MUSTTAIL return peek();
} else {
return c;
}
}
@@ -1943,8 +1942,6 @@ static Token yylex_NORMAL() {
if (Symbol const *sym = sym_FindExactSymbol(std::get<std::string>(token.value));
sym && sym->type == SYM_EQUS) {
beginExpansion(sym->getEqus(), sym->name);
// We cannot do `MUSTTAIL return yylex_NORMAL();` because tail call optimization
// requires the return value to be "trivially destructible", and `Token` is not.
continue; // Restart, reading from the new buffer
}
}