ref: eba06404f036f17819b6a51e01bd246ef993f7d2
parent: 9558ccea1bb2e8af593cfe8f26e541731318ce3a
author: Rangi <[email protected]>
date: Fri Mar 26 14:13:01 EDT 2021
`peek(0)` => `peek()` This does not completely refactor `peek` as #708 suggested, to make it shift and cache a character itself. However it does simplify the lexer code.
--- a/src/asm/lexer.c
+++ b/src/asm/lexer.c
@@ -708,8 +708,7 @@
return expansion;
}
-static void beginExpansion(size_t distance, uint8_t skip, char const *str, bool owned,
- char const *name)
+static void beginExpansion(uint8_t skip, char const *str, bool owned, char const *name)
{size_t size = strlen(str);
@@ -717,7 +716,8 @@
if (!size)
return;
- distance += lexerState->expansionOfs; /* Distance argument is relative to read offset! */
+ /* Distance argument is relative to read offset! */
+ size_t distance = lexerState->expansionOfs;
/* Increase the total length of all parents, and return the topmost one */
struct Expansion *parent = NULL;
@@ -868,56 +868,58 @@
static void shiftChar(void);
static char const *readInterpolation(void);
-static int peek(uint8_t distance)
+static int peek(void)
{int c;
restart:
- c = peekInternal(distance);
+ c = peekInternal(0);
- if (distance >= lexerState->macroArgScanDistance) {- lexerState->macroArgScanDistance = distance + 1; /* Do not consider again */
- if (c == '\\' && !lexerState->disableMacroArgs) {- /* If character is a backslash, check for a macro arg */
- lexerState->macroArgScanDistance++;
- c = peekInternal(distance + 1);
- if (isMacroChar(c)) {- char const *str = readMacroArg(c);
+ if (lexerState->macroArgScanDistance > 0)
+ return c;
- /*
- * If the macro arg is an empty string, it cannot be
- * expanded, so skip it and keep peeking.
- */
- if (!str[0]) {- shiftChar();
- shiftChar();
- goto restart;
- }
+ lexerState->macroArgScanDistance = 1; /* Do not consider again */
- beginExpansion(distance, 2, str, c == '#', NULL);
+ if (c == '\\' && !lexerState->disableMacroArgs) {+ /* If character is a backslash, check for a macro arg */
+ lexerState->macroArgScanDistance++;
+ c = peekInternal(1);
+ if (isMacroChar(c)) {+ char const *str = readMacroArg(c);
- /*
- * Assuming macro args can't be recursive (I'll be damned if a way
- * is found...), then we mark the entire macro arg as scanned;
- * however, the two macro arg characters (\1) will be ignored,
- * so they shouldn't be counted in the scan distance!
- */
- lexerState->macroArgScanDistance += strlen(str) - 2;
-
- c = str[0];
- } else {- c = '\\';
- }
- } else if (c == '{' && !lexerState->disableInterpolation) {- /* If character is an open brace, do symbol interpolation */
- shiftChar();
- char const *ptr = readInterpolation();
-
- if (ptr) {- beginExpansion(distance, 0, ptr, false, ptr);
+ /*
+ * If the macro arg is an empty string, it cannot be
+ * expanded, so skip it and keep peeking.
+ */
+ if (!str[0]) {+ shiftChar();
+ shiftChar();
goto restart;
}
+
+ beginExpansion(2, str, c == '#', NULL);
+
+ /*
+ * Assuming macro args can't be recursive (I'll be damned if a way
+ * is found...), then we mark the entire macro arg as scanned;
+ * however, the two macro arg characters (\1) will be ignored,
+ * so they shouldn't be counted in the scan distance!
+ */
+ lexerState->macroArgScanDistance += strlen(str) - 2;
+
+ c = str[0];
+ } else {+ c = '\\';
}
+ } else if (c == '{' && !lexerState->disableInterpolation) {+ /* If character is an open brace, do symbol interpolation */
+ shiftChar();
+ char const *ptr = readInterpolation();
+
+ if (ptr) {+ beginExpansion(0, ptr, false, ptr);
+ goto restart;
+ }
}
return c;
@@ -930,7 +932,7 @@
if (lexerState->captureSize + 1 >= lexerState->captureCapacity)
reallocCaptureBuf();
/* TODO: improve this? */
- lexerState->captureBuf[lexerState->captureSize] = peek(0);
+ lexerState->captureBuf[lexerState->captureSize] = peek();
}
lexerState->captureSize++;
}
@@ -994,7 +996,7 @@
static int nextChar(void)
{- int c = peek(0);
+ int c = peek();
/* If not at EOF, advance read position */
if (c != EOF)
@@ -1004,7 +1006,7 @@
static void handleCRLF(int c)
{- if (c == '\r' && peek(0) == '\n')
+ if (c == '\r' && peek() == '\n')
shiftChar();
}
@@ -1069,13 +1071,13 @@
nextLine();
continue;
case '/':
- if (peek(0) == '*') {+ if (peek() == '*') {warning(WARNING_NESTED_COMMENT,
"/* in block comment\n");
}
continue;
case '*':
- if (peek(0) == '/') {+ if (peek() == '/') {shiftChar();
goto finish;
}
@@ -1097,7 +1099,7 @@
lexerState->disableMacroArgs = true;
lexerState->disableInterpolation = true;
for (;;) {- int c = peek(0);
+ int c = peek();
if (c == EOF || c == '\r' || c == '\n')
break;
@@ -1113,7 +1115,7 @@
{ dbgPrint("Beginning line continuation\n"); for (;;) {- int c = peek(0);
+ int c = peek();
if (isWhitespace(c)) {shiftChar();
@@ -1144,7 +1146,7 @@
do {shiftChar();
n++;
- } while (peek(0) == c);
+ } while (peek() == c);
sym_WriteAnonLabelName(yylval.tzSym, n, c == '-');
}
@@ -1156,7 +1158,7 @@
uint32_t value = baseValue;
for (;; shiftChar()) {- int c = peek(0);
+ int c = peek();
if (c == '_')
continue;
@@ -1176,7 +1178,7 @@
dbgPrint("Reading fractional part\n"); for (;; shiftChar()) {- int c = peek(0);
+ int c = peek();
if (c == '_')
continue;
@@ -1187,7 +1189,7 @@
"Precision of fixed-point constant is too large\n");
/* Discard any additional digits */
shiftChar();
- while (c = peek(0), (c >= '0' && c <= '9') || c == '_')
+ while (c = peek(), (c >= '0' && c <= '9') || c == '_')
shiftChar();
break;
}
@@ -1214,7 +1216,7 @@
dbgPrint("Reading binary number with digits [%c,%c]\n", binDigits[0], binDigits[1]); for (;; shiftChar()) {- int c = peek(0);
+ int c = peek();
int bit;
if (c == binDigits[0])
@@ -1240,7 +1242,7 @@
dbgPrint("Reading hex number\n"); for (;; shiftChar()) {- int c = peek(0);
+ int c = peek();
if (c >= 'a' && c <= 'f') /* Convert letters to right after digits */
c = c - 'a' + 10;
@@ -1276,7 +1278,7 @@
dbgPrint("Reading gfx constant with digits [%c,%c,%c,%c]\n",gfxDigits[0], gfxDigits[1], gfxDigits[2], gfxDigits[3]);
for (;;) {- int c = peek(0);
+ int c = peek();
uint32_t pixel;
if (c == gfxDigits[0])
@@ -1325,7 +1327,7 @@
size_t i;
for (i = 1; ; i++) {- int c = peek(0);
+ int c = peek();
/* If that char isn't in the symbol charset, end */
if ((c > '9' || c < '0')
@@ -1370,7 +1372,7 @@
struct FormatSpec fmt = fmt_NewSpec();
for (;;) {- int c = peek(0);
+ int c = peek();
if (c == '{') { /* Nested interpolation */shiftChar();
@@ -1377,7 +1379,7 @@
char const *ptr = readInterpolation();
if (ptr) {- beginExpansion(0, 0, ptr, false, ptr);
+ beginExpansion(0, ptr, false, ptr);
continue; /* Restart, reading from the new buffer */
}
} else if (c == EOF || c == '\r' || c == '\n' || c == '"') {@@ -1483,9 +1485,9 @@
bool multiline = false;
// We reach this function after reading a single quote, but we also support triple quotes
- if (peek(0) == '"') {+ if (peek() == '"') {shiftChar();
- if (peek(0) == '"') {+ if (peek() == '"') {// """ begins a multi-line string
shiftChar();
multiline = true;
@@ -1496,7 +1498,7 @@
}
for (;;) {- int c = peek(0);
+ int c = peek();
// '\r', '\n' or EOF ends a single-line string early
if (c == EOF || (!multiline && (c == '\r' || c == '\n'))) {@@ -1519,10 +1521,10 @@
case '"':
if (multiline) {// Only """ ends a multi-line string
- if (peek(0) != '"')
+ if (peek() != '"')
break;
shiftChar();
- if (peek(0) != '"') {+ if (peek() != '"') { append_yylval_tzString('"');break;
}
@@ -1531,7 +1533,7 @@
goto finish;
case '\\': // Character escape or macro arg
- c = peek(0);
+ c = peek();
switch (c) {case '\\':
case '"':
@@ -1632,10 +1634,10 @@
// We reach this function after reading a single quote, but we also support triple quotes
append_yylval_tzString('"');- if (peek(0) == '"') {+ if (peek() == '"') { append_yylval_tzString('"');shiftChar();
- if (peek(0) == '"') {+ if (peek() == '"') {// """ begins a multi-line string
append_yylval_tzString('"');shiftChar();
@@ -1647,7 +1649,7 @@
}
for (;;) {- int c = peek(0);
+ int c = peek();
// '\r', '\n' or EOF ends a single-line string early
if (c == EOF || (!multiline && (c == '\r' || c == '\n'))) {@@ -1670,11 +1672,11 @@
case '"':
if (multiline) {// Only """ ends a multi-line string
- if (peek(0) != '"')
+ if (peek() != '"')
break;
append_yylval_tzString('"');shiftChar();
- if (peek(0) != '"')
+ if (peek() != '"')
break;
append_yylval_tzString('"');shiftChar();
@@ -1683,7 +1685,7 @@
goto finish;
case '\\': // Character escape or macro arg
- c = peek(0);
+ c = peek();
switch (c) {// Character escape
case '\\':
@@ -1833,7 +1835,7 @@
/* Handle ambiguous 1- or 2-char tokens */
case '*': /* Either MUL or EXP */
- if (peek(0) == '*') {+ if (peek() == '*') {shiftChar();
return T_OP_EXP;
}
@@ -1840,7 +1842,7 @@
return T_OP_MUL;
case '/': /* Either division or a block comment */
- if (peek(0) == '*') {+ if (peek() == '*') {shiftChar();
discardBlockComment();
break;
@@ -1848,7 +1850,7 @@
return T_OP_DIV;
case '|': /* Either binary or logical OR */
- if (peek(0) == '|') {+ if (peek() == '|') {shiftChar();
return T_OP_LOGICOR;
}
@@ -1855,7 +1857,7 @@
return T_OP_OR;
case '=': /* Either SET alias, or EQ */
- if (peek(0) == '=') {+ if (peek() == '=') {shiftChar();
return T_OP_LOGICEQU;
}
@@ -1862,7 +1864,7 @@
return T_POP_EQUAL;
case '<': /* Either a LT, LTE, or left shift */
- switch (peek(0)) {+ switch (peek()) {case '=':
shiftChar();
return T_OP_LOGICLE;
@@ -1874,7 +1876,7 @@
}
case '>': /* Either a GT, GTE, or right shift */
- switch (peek(0)) {+ switch (peek()) {case '=':
shiftChar();
return T_OP_LOGICGE;
@@ -1886,7 +1888,7 @@
}
case '!': /* Either a NEQ, or negation */
- if (peek(0) == '=') {+ if (peek() == '=') {shiftChar();
return T_OP_LOGICNE;
}
@@ -1895,7 +1897,7 @@
/* Handle colon, which may begin an anonymous label ref */
case ':':
- c = peek(0);
+ c = peek();
if (c != '+' && c != '-')
return T_COLON;
@@ -1910,11 +1912,11 @@
/* Attempt to match `$ff00+c` */
if (yylval.nConstValue == 0xff00) {/* Whitespace is ignored anyways */
- while (isWhitespace(c = peek(0)))
+ while (isWhitespace(c = peek()))
shiftChar();
if (c == '+') {shiftChar();
- while (isWhitespace(c = peek(0)))
+ while (isWhitespace(c = peek()))
shiftChar();
if (c == 'c' || c == 'C') {shiftChar();
@@ -1937,7 +1939,7 @@
case '8':
case '9':
readNumber(10, c - '0');
- if (peek(0) == '.') {+ if (peek() == '.') {shiftChar();
readFractionalPart();
}
@@ -1944,7 +1946,7 @@
return T_NUMBER;
case '&':
- secondChar = peek(0);
+ secondChar = peek();
if (secondChar == '&') {shiftChar();
return T_OP_LOGICAND;
@@ -1955,7 +1957,7 @@
return T_OP_AND;
case '%': /* Either a modulo, or a binary constant */
- secondChar = peek(0);
+ secondChar = peek();
if (secondChar != binDigits[0] && secondChar != binDigits[1])
return T_OP_MOD;
@@ -2016,12 +2018,12 @@
if (sym && sym->type == SYM_EQUS) {char const *s = sym_GetStringValue(sym);
- beginExpansion(0, 0, s, false, sym->name);
+ beginExpansion(0, s, false, sym->name);
continue; /* Restart, reading from the new buffer */
}
}
- if (tokenType == T_ID && (lexerState->atLineStart || peek(0) == ':'))
+ if (tokenType == T_ID && (lexerState->atLineStart || peek() == ':'))
return T_LABEL;
return tokenType;
@@ -2047,11 +2049,11 @@
int c;
/* Trim left whitespace (stops at a block comment or line continuation) */
- while (isWhitespace(peek(0)))
+ while (isWhitespace(peek()))
shiftChar();
for (;;) {- c = peek(0);
+ c = peek();
switch (c) {case '"': /* String literals inside macro args */
@@ -2061,7 +2063,7 @@
case ';': /* Comments inside macro args */
discardComment();
- c = peek(0);
+ c = peek();
/* fallthrough */
case ',': /* End of macro arg */
case '\r':
@@ -2071,7 +2073,7 @@
case '/': /* Block comments inside macro args */
shiftChar();
- if (peek(0) == '*') {+ if (peek() == '*') {shiftChar();
discardBlockComment();
continue;
@@ -2081,7 +2083,7 @@
case '\\': /* Character escape */
shiftChar();
- c = peek(0);
+ c = peek();
switch (c) {case ',': /* Escape `\,` only inside a macro arg */
@@ -2196,7 +2198,7 @@
int c;
for (;;) {- c = peek(0);
+ c = peek();
if (!isWhitespace(c))
break;
shiftChar();
@@ -2291,7 +2293,7 @@
int c;
for (;;) {- c = peek(0);
+ c = peek();
if (!isWhitespace(c))
break;
shiftChar();