Bug 1542736 - Part 5: Replace std::isdigit with mozilla::IsAsciiDigit. r=jwalden

mozilla::IsAsciiDigit is equivalent to std::isdigit, except it's not necessary
to worry about UB when calling it with an input which can't be represented as
`unsigned char`.

Differential Revision: https://phabricator.services.mozilla.com/D26508

--HG--
extra : moz-landing-system : lando

js/src/gc/GC.cpp

@@ -196,11 +196,11 @@
 #include "mozilla/Move.h"
 #include "mozilla/Range.h"
 #include "mozilla/ScopeExit.h"
+#include "mozilla/TextUtils.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/TypeTraits.h"
 #include "mozilla/Unused.h"
 
-#include <ctype.h>
 #include <initializer_list>
 #include <string.h>
 #ifndef XP_WIN
@@ -1158,7 +1158,7 @@ static bool ParseZealModeNumericParam(CharRange text, uint32_t* paramOut) {
   }
 
   for (auto c : text) {
-    if (!isdigit(c)) {
+    if (!mozilla::IsAsciiDigit(c)) {
       return false;
     }
   }

js/src/jsdate.cpp

@@ -58,6 +58,7 @@ using mozilla::ArrayLength;
 using mozilla::Atomic;
 using mozilla::BitwiseCast;
 using mozilla::IsAsciiAlpha;
+using mozilla::IsAsciiDigit;
 using mozilla::IsFinite;
 using mozilla::IsNaN;
 using mozilla::NumbersAreIdentical;
@@ -2891,11 +2892,12 @@ static bool ToLocaleFormatHelper(JSContext* cx, HandleObject obj,
     if (strcmp(format, "%x") == 0 && result_len >= 6 &&
         /* Format %x means use OS settings, which may have 2-digit yr, so
            hack end of 3/11/22 or 11.03.22 or 11Mar22 to use 4-digit yr...*/
-        !isdigit(buf[result_len - 3]) && isdigit(buf[result_len - 2]) &&
-        isdigit(buf[result_len - 1]) &&
+        !IsAsciiDigit(buf[result_len - 3]) &&
+        IsAsciiDigit(buf[result_len - 2]) &&
+        IsAsciiDigit(buf[result_len - 1]) &&
         /* ...but not if starts with 4-digit year, like 2022/3/11. */
-        !(isdigit(buf[0]) && isdigit(buf[1]) && isdigit(buf[2]) &&
-          isdigit(buf[3]))) {
+        !(IsAsciiDigit(buf[0]) && IsAsciiDigit(buf[1]) &&
+          IsAsciiDigit(buf[2]) && IsAsciiDigit(buf[3]))) {
       int year = int(YearFromTime(localTime));
       snprintf(buf + (result_len - 2), (sizeof buf) - (result_len - 2), "%d",
                year);

js/src/vm/Initialization.cpp

@@ -9,8 +9,7 @@
 #include "js/Initialization.h"
 
 #include "mozilla/Assertions.h"
-
-#include <ctype.h>
+#include "mozilla/TextUtils.h"
 
 #include "jstypes.h"
 
@@ -46,7 +45,7 @@ InitState JS::detail::libraryInitState;
 static unsigned MessageParameterCount(const char* format) {
   unsigned numfmtspecs = 0;
   for (const char* fmt = format; *fmt != '\0'; fmt++) {
-    if (*fmt == '{' && isdigit(fmt[1])) {
+    if (*fmt == '{' && mozilla::IsAsciiDigit(fmt[1])) {
       ++numfmtspecs;
     }
   }

js/src/vm/JSContext.cpp

@@ -17,7 +17,6 @@
 #include "mozilla/TextUtils.h"
 #include "mozilla/Unused.h"
 
-#include <ctype.h>
 #include <stdarg.h>
 #include <string.h>
 #ifdef ANDROID
@@ -738,7 +737,7 @@ bool ExpandErrorArgumentsHelper(JSContext* cx, JSErrorCallback callback,
         fmt = efs->format;
         while (*fmt) {
           if (*fmt == '{') {
-            if (isdigit(fmt[1])) {
+            if (mozilla::IsAsciiDigit(fmt[1])) {
               int d = AsciiDigitToNumber(fmt[1]);
               MOZ_RELEASE_ASSERT(d < args.count());
               strncpy(out, args.args(d), args.lengths(d));