Factor out isBinDigit and parseHexDigit utility functions

include/util.hpp

@@ -7,6 +7,7 @@
 #include <ctype.h>
 #include <numeric>
 #include <stddef.h>
+#include <stdint.h>
 #include <string>
 #include <unordered_map>
 
@@ -25,6 +26,8 @@ bool isAlphanumeric(int c);
 bool startsIdentifier(int c);
 bool continuesIdentifier(int c);
 
+uint8_t parseHexDigit(int c);
+
 char const *printChar(int c);
 
 struct Uppercase {

src/asm/lexer.cpp

@@ -1009,6 +1009,10 @@ static bool isValidDigit(char c) {
 	return isAlphanumeric(c) || c == '.' || c == '#' || c == '@';
 }
 
+static bool isBinDigit(int c) {
+	return c == '0' || c == '1' || c == options.binDigits[0] || c == options.binDigits[1];
+}
+
 static bool checkDigitErrors(char const *digits, size_t n, char const *type) {
 	for (size_t i = 0; i < n; ++i) {
 		char c = digits[i];
@@ -1074,10 +1078,7 @@ static uint32_t readBinaryNumber(char const *prefix) {
 		if (value > (UINT32_MAX - bit) / 2) {
 			warning(WARNING_LARGE_CONSTANT, "Integer constant is too large");
 			// Discard any additional digits
-			skipChars([](int d) {
-				return d == '0' || d == '1' || d == options.binDigits[0]
-				       || d == options.binDigits[1] || d == '_';
-			});
+			skipChars([](int d) { return isBinDigit(d) || d == '_'; });
 			return 0;
 		}
 		value = value * 2 + bit;
@@ -1107,11 +1108,10 @@ static uint32_t readOctalNumber(char const *prefix) {
 			continue;
 		}
 
-		if (isOctDigit(c)) {
-			c = c - '0';
-		} else {
+		if (!isOctDigit(c)) {
 			break;
 		}
+		c = c - '0';
 		empty = false;
 		nonDigit = false;
 
@@ -1148,11 +1148,10 @@ static uint32_t readDecimalNumber(int initial) {
 			continue;
 		}
 
-		if (isDigit(c)) {
-			c = c - '0';
-		} else {
+		if (!isDigit(c)) {
 			break;
 		}
+		c = c - '0';
 		nonDigit = false;
 
 		if (value > (UINT32_MAX - c) / 10) {
@@ -1185,15 +1184,10 @@ static uint32_t readHexNumber(char const *prefix) {
 			continue;
 		}
 
-		if (c >= 'a' && c <= 'f') {
-			c = c - 'a' + 10;
-		} else if (c >= 'A' && c <= 'F') {
-			c = c - 'A' + 10;
-		} else if (isDigit(c)) {
-			c = c - '0';
-		} else {
+		if (!isHexDigit(c)) {
 			break;
 		}
+		c = parseHexDigit(c);
 		empty = false;
 		nonDigit = false;
 
@@ -1834,8 +1828,7 @@ static Token yylex_NORMAL() {
 
 		case '%': // Either %=, MOD, or a binary constant
 			c = peek();
-			if (c == '0' || c == '1' || c == options.binDigits[0] || c == options.binDigits[1]
-			    || c == '_') {
+			if (isBinDigit(c) || c == '_') {
 				return Token(T_(NUMBER), readBinaryNumber("'%'"));
 			}
 			return oneOrTwo('=', T_(POP_MODEQ), T_(OP_MOD));

src/gfx/pal_spec.cpp

@@ -37,24 +37,11 @@ static void skipBlankSpace(Str const &str, size_t &pos) {
 	pos = std::min(str.find_first_not_of(" \t"sv, pos), str.length());
 }
 
-static constexpr uint8_t nibble(char c) {
-	if (c >= 'a') {
-		assume(c <= 'f');
-		return c - 'a' + 10;
-	} else if (c >= 'A') {
-		assume(c <= 'F');
-		return c - 'A' + 10;
-	} else {
-		assume(isDigit(c));
-		return c - '0';
-	}
+static uint8_t toHex(char c1, char c2) {
+	return parseHexDigit(c1) * 16 + parseHexDigit(c2);
 }
 
-static constexpr uint8_t toHex(char c1, char c2) {
-	return nibble(c1) * 16 + nibble(c2);
-}
-
-static constexpr uint8_t singleToHex(char c) {
+static uint8_t singleToHex(char c) {
 	return toHex(c, c);
 }
 

src/link/lexer.cpp

@@ -108,7 +108,7 @@ static yy::parser::symbol_type parseDecNumber(int c) {
 }
 
 static bool isBinDigit(int c) {
-	return c >= '0' && c <= '1';
+	return c == '0' || c == '1';
 }
 
 static yy::parser::symbol_type parseBinNumber(char const *prefix) {
@@ -149,18 +149,6 @@ static yy::parser::symbol_type parseOctNumber(char const *prefix) {
 	return yy::parser::make_number(number);
 }
 
-static uint8_t parseHexDigit(int c) {
-	if (isDigit(c)) {
-		return c - '0';
-	} else if (c >= 'A' && c <= 'F') {
-		return c - 'A' + 10;
-	} else if (c >= 'a' && c <= 'f') {
-		return c - 'a' + 10;
-	} else {
-		unreachable_(); // LCOV_EXCL_LINE
-	}
-}
-
 static yy::parser::symbol_type parseHexNumber(char const *prefix) {
 	LexerStackEntry &context = lexerStack.back();
 	int c = context.file.sgetc();

src/util.cpp

@@ -5,6 +5,8 @@
 #include <stdint.h>
 #include <stdio.h>
 
+#include "helpers.hpp" // assume
+
 bool isNewline(int c) {
 	return c == '\r' || c == '\n';
 }
@@ -51,6 +53,17 @@ bool continuesIdentifier(int c) {
 	return startsIdentifier(c) || isDigit(c) || c == '#' || c == '$' || c == '@';
 }
 
+uint8_t parseHexDigit(int c) {
+	if (c >= 'A' && c <= 'F') {
+		return c - 'A' + 10;
+	} else if (c >= 'a' && c <= 'f') {
+		return c - 'a' + 10;
+	} else {
+		assume(isDigit(c));
+		return c - '0';
+	}
+}
+
 char const *printChar(int c) {
 	// "'A'" + '\0': 4 bytes
 	// "'\\n'" + '\0': 5 bytes