[regexp] Fix -Wshadow warnings

Bug: v8:12244,v8:12245
Change-Id: I5b908f056222c57e796fb76e86ceea9a77cde77f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3265066Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77782}

src/regexp/regexp-compiler-tonode.cc

@@ -637,16 +637,16 @@ void RegExpDisjunction::RationalizeConsecutiveAtoms(RegExpCompiler* compiler) {
     while (i < length) {
       alternative = alternatives->at(i);
       if (!alternative->IsAtom()) break;
-      RegExpAtom* const atom = alternative->AsAtom();
+      RegExpAtom* const alt_atom = alternative->AsAtom();
 #ifdef V8_INTL_SUPPORT
-      icu::UnicodeString new_prefix(atom->data().at(0));
+      icu::UnicodeString new_prefix(alt_atom->data().at(0));
       if (new_prefix != common_prefix) {
         if (!IsIgnoreCase(compiler->flags())) break;
         if (common_prefix.caseCompare(new_prefix, U_FOLD_CASE_DEFAULT) != 0)
           break;
       }
 #else
-      unibrow::uchar new_prefix = atom->data().at(0);
+      unibrow::uchar new_prefix = alt_atom->data().at(0);
       if (new_prefix != common_prefix) {
         if (!IsIgnoreCase(compiler->flags())) break;
         unibrow::Mapping<unibrow::Ecma262Canonicalize>* canonicalize =
@@ -656,7 +656,7 @@ void RegExpDisjunction::RationalizeConsecutiveAtoms(RegExpCompiler* compiler) {
         if (new_prefix != common_prefix) break;
       }
 #endif  // V8_INTL_SUPPORT
-      prefix_length = std::min(prefix_length, atom->length());
+      prefix_length = std::min(prefix_length, alt_atom->length());
       i++;
     }
     if (i > first_with_prefix + 2) {
@@ -666,19 +666,20 @@ void RegExpDisjunction::RationalizeConsecutiveAtoms(RegExpCompiler* compiler) {
       // common prefix if the terms were similar or presorted in the input.
       // Find out how long the common prefix is.
       int run_length = i - first_with_prefix;
-      RegExpAtom* const atom = alternatives->at(first_with_prefix)->AsAtom();
+      RegExpAtom* const alt_atom =
+          alternatives->at(first_with_prefix)->AsAtom();
       for (int j = 1; j < run_length && prefix_length > 1; j++) {
         RegExpAtom* old_atom =
             alternatives->at(j + first_with_prefix)->AsAtom();
         for (int k = 1; k < prefix_length; k++) {
-          if (atom->data().at(k) != old_atom->data().at(k)) {
+          if (alt_atom->data().at(k) != old_atom->data().at(k)) {
             prefix_length = k;
             break;
           }
         }
       }
       RegExpAtom* prefix =
-          zone->New<RegExpAtom>(atom->data().SubVector(0, prefix_length));
+          zone->New<RegExpAtom>(alt_atom->data().SubVector(0, prefix_length));
       ZoneList<RegExpTree*>* pair = zone->New<ZoneList<RegExpTree*>>(2, zone);
       pair->Add(prefix, zone);
       ZoneList<RegExpTree*>* suffixes =
@@ -741,12 +742,12 @@ void RegExpDisjunction::FixSingleCharacterDisjunctions(
     while (i < length) {
       alternative = alternatives->at(i);
       if (!alternative->IsAtom()) break;
-      RegExpAtom* const atom = alternative->AsAtom();
-      if (atom->length() != 1) break;
+      RegExpAtom* const alt_atom = alternative->AsAtom();
+      if (alt_atom->length() != 1) break;
       DCHECK_IMPLIES(IsUnicode(flags),
-                     !unibrow::Utf16::IsLeadSurrogate(atom->data().at(0)));
+                     !unibrow::Utf16::IsLeadSurrogate(alt_atom->data().at(0)));
       contains_trail_surrogate |=
-          unibrow::Utf16::IsTrailSurrogate(atom->data().at(0));
+          unibrow::Utf16::IsTrailSurrogate(alt_atom->data().at(0));
       i++;
     }
     if (i > first_in_run + 1) {

src/regexp/regexp-compiler.cc

@@ -1703,7 +1703,7 @@ void TextNode::GetQuickCheckDetails(QuickCheckDetails* details,
         uint32_t common_bits = ~SmearBitsRight(differing_bits);
         uint32_t bits = (first_from & common_bits);
         for (int i = first_range + 1; i < ranges->length(); i++) {
-          CharacterRange range = ranges->at(i);
+          range = ranges->at(i);
           const base::uc32 from = range.from();
           if (from > char_mask) continue;
           const base::uc32 to =
@@ -1718,8 +1718,8 @@ void TextNode::GetQuickCheckDetails(QuickCheckDetails* details,
           new_common_bits = ~SmearBitsRight(new_common_bits);
           common_bits &= new_common_bits;
           bits &= new_common_bits;
-          uint32_t differing_bits = (from & common_bits) ^ bits;
-          common_bits ^= differing_bits;
+          uint32_t new_differing_bits = (from & common_bits) ^ bits;
+          common_bits ^= new_differing_bits;
           bits &= common_bits;
         }
         pos->mask = common_bits;
@@ -3856,8 +3856,8 @@ void TextNode::FillInBMInfo(Isolate* isolate, int initial_offset, int budget,
           int length = GetCaseIndependentLetters(
               isolate, character, bm->max_char() == String::kMaxOneByteCharCode,
               chars, 4);
-          for (int j = 0; j < length; j++) {
-            bm->Set(offset, chars[j]);
+          for (int k = 0; k < length; k++) {
+            bm->Set(offset, chars[k]);
           }
         } else {
           if (character <= max_char) bm->Set(offset, character);

src/regexp/regexp-dotprinter.cc

@@ -130,8 +130,8 @@ void DotPrinterImpl::VisitText(TextNode* that) {
     switch (elm.text_type()) {
       case TextElement::ATOM: {
         base::Vector<const base::uc16> data = elm.atom()->data();
-        for (int i = 0; i < data.length(); i++) {
-          os_ << static_cast<char>(data[i]);
+        for (int j = 0; j < data.length(); j++) {
+          os_ << static_cast<char>(data[j]);
         }
         break;
       }