https://bugzilla.mozilla.org/show_bug.cgi?id=1954003
https://phabricator.services.mozilla.com/D241583
https://github.com/mozilla-firefox/firefox/commit/6d368d85ef52ce67141f44f3fdbfd51ef23f14e6
From 02f94f3cdc97fc3b2bc4654658230c2d896417ae Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh+mozilla@glandium.org>
Date: Mon, 17 Mar 2025 23:31:43 +0000
Subject: [PATCH] Bug 1954003 - Fix new implicit-int-conversion warnings from
 clang 21. r=spidermonkey-reviewers,arai

/builds/worker/workspace/obj-build/dist/include/js/Conversions.h:364:70: error: implicit conversion loses integer precision: 'int' to 'unsigned char' [-Werror,-Wimplicit-int-conversion]
  364 |   return (bits & mozilla::FloatingPoint<double>::kSignBit) ? ~result + 1
      |   ~~~~~~                                                     ~~~~~~~~^~~
/builds/worker/workspace/obj-build/dist/include/js/Conversions.h:544:42: note: in instantiation of function template specialization 'JS::ToUnsignedInteger<unsigned char>' requested here
  544 | inline int8_t ToUint8(double d) { return ToUnsignedInteger<uint8_t>(d); }
      |                                          ^
/builds/worker/workspace/obj-build/dist/include/js/Conversions.h:364:70: error: implicit conversion loses integer precision: 'int' to 'unsigned short' [-Werror,-Wimplicit-int-conversion]
  364 |   return (bits & mozilla::FloatingPoint<double>::kSignBit) ? ~result + 1
      |   ~~~~~~                                                     ~~~~~~~~^~~
/builds/worker/workspace/obj-build/dist/include/js/Conversions.h:549:45: note: in instantiation of function template specialization 'JS::ToUnsignedInteger<unsigned short>' requested here
  549 | inline uint16_t ToUint16(double d) { return ToUnsignedInteger<uint16_t>(d); }
      |                                             ^

Differential Revision: https://phabricator.services.mozilla.com/D241584
--- a/js/public/Conversions.h
+++ b/js/public/Conversions.h
@@ -361,8 +361,9 @@ inline UnsignedInteger ToUnsignedInteger(double d) {
   }
 
   // Compute the congruent value in the signed range.
-  return (bits & mozilla::FloatingPoint<double>::kSignBit) ? ~result + 1
-                                                           : result;
+  return (bits & mozilla::FloatingPoint<double>::kSignBit)
+             ? UnsignedInteger(~result) + 1
+             : result;
 }
 
 template <typename SignedInteger>

https://phabricator.services.mozilla.com/D241582
https://github.com/mozilla-firefox/firefox/commit/3053f782bbb35895d632855bb5007282d7ec45e2

From 3053f782bbb35895d632855bb5007282d7ec45e2 Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh+mozilla@glandium.org>
Date: Mon, 17 Mar 2025 23:31:42 +0000
Subject: [PATCH] Bug 1954003 - Fix new implicit-int-conversion warnings from
 clang 21. r=dom-core,mccr8

/builds/worker/checkouts/gecko/dom/base/nsINode.h:2055:32: error: implicit conversion loses integer precision: 'int' to 'uint32_t' (aka 'unsigned int') [-Werror,-Wimplicit-int-conversion]
 2055 |     mBoolFlags = (mBoolFlags & ~(1 << name)) | (value << name);
      |                              ~ ^~~~~~~~~~~~
/builds/worker/checkouts/gecko/dom/base/nsINode.h:2067:19: error: implicit conversion loses integer precision: 'int' to 'uint32_t' (aka 'unsigned int') [-Werror,-Wimplicit-int-conversion]
 2067 |     mBoolFlags &= ~(1 << name);
      |                ~~ ^~~~~~~~~~~~

Differential Revision: https://phabricator.services.mozilla.com/D241582
--- a/dom/base/nsINode.h
+++ b/dom/base/nsINode.h
@@ -2065,25 +2065,25 @@ class nsINode : public mozilla::dom::EventTarget {
   void SetBoolFlag(BooleanFlag name, bool value) {
     static_assert(BooleanFlagCount <= 8 * sizeof(mBoolFlags),
                   "Too many boolean flags");
-    mBoolFlags = (mBoolFlags & ~(1 << name)) | (value << name);
+    mBoolFlags = (mBoolFlags & ~(1U << name)) | (value << name);
   }
 
   void SetBoolFlag(BooleanFlag name) {
     static_assert(BooleanFlagCount <= 8 * sizeof(mBoolFlags),
                   "Too many boolean flags");
-    mBoolFlags |= (1 << name);
+    mBoolFlags |= (1U << name);
   }
 
   void ClearBoolFlag(BooleanFlag name) {
     static_assert(BooleanFlagCount <= 8 * sizeof(mBoolFlags),
                   "Too many boolean flags");
-    mBoolFlags &= ~(1 << name);
+    mBoolFlags &= ~(1U << name);
   }
 
   bool GetBoolFlag(BooleanFlag name) const {
     static_assert(BooleanFlagCount <= 8 * sizeof(mBoolFlags),
                   "Too many boolean flags");
-    return mBoolFlags & (1 << name);
+    return mBoolFlags & (1U << name);
   }
 
  public:

https://phabricator.services.mozilla.com/D241584
https://github.com/mozilla-firefox/firefox/commit/02f94f3cdc97fc3b2bc4654658230c2d896417ae

From 6d368d85ef52ce67141f44f3fdbfd51ef23f14e6 Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh+mozilla@glandium.org>
Date: Mon, 17 Mar 2025 23:31:43 +0000
Subject: [PATCH] Bug 1954003 - Fix new implicit-int-conversion warnings from
 clang 21. r=gfx-reviewers,lsalzman

/builds/worker/checkouts/gecko/dom/canvas/CanvasRenderingContext2D.cpp:6284:9: error: implicit conversion loses integer precision: 'int32_t' (aka 'int') to 'uint32_t' (aka 'unsigned int') [-Werror,-Wimplicit-int-conversion]
 6284 |     w = -aSw;
      |       ~ ^~~~
/builds/worker/checkouts/gecko/dom/canvas/CanvasRenderingContext2D.cpp:6290:9: error: implicit conversion loses integer precision: 'int32_t' (aka 'int') to 'uint32_t' (aka 'unsigned int') [-Werror,-Wimplicit-int-conversion]
 6290 |     h = -aSh;
      |       ~ ^~~~

Differential Revision: https://phabricator.services.mozilla.com/D241583
--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -6281,13 +6281,13 @@ already_AddRefed<ImageData> CanvasRenderingContext2D::GetImageData(
   // relevant direction.
   uint32_t w, h;
   if (aSw < 0) {
-    w = -aSw;
+    w = uint32_t(-aSw);
     aSx -= w;
   } else {
     w = aSw;
   }
   if (aSh < 0) {
-    h = -aSh;
+    h = uint32_t(-aSh);
     aSy -= h;
   } else {
     h = aSh;