diff -Naur a/Source/JavaScriptCore/generate-bytecode-files b/Source/JavaScriptCore/generate-bytecode-files
--- a/Source/JavaScriptCore/generate-bytecode-files	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/JavaScriptCore/generate-bytecode-files	2021-04-19 16:42:50.234458274 +0200
@@ -163,7 +163,7 @@
         initBytecodesFile = openOrExit(initASMFileName, "w")
 
     try:
-        bytecodeSections = json.load(bytecodeFile, encoding = "utf-8")
+        bytecodeSections = json.load(bytecodeFile)
     except:
         print("Unexpected error parsing {0}: {1}".format(bytecodeJSONFile, sys.exc_info()))
 
diff -Naur a/Source/WebCore/css/makegrammar.pl b/Source/WebCore/css/makegrammar.pl
--- a/Source/WebCore/css/makegrammar.pl	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/WebCore/css/makegrammar.pl	2021-04-19 16:40:59.169942598 +0200
@@ -73,25 +73,6 @@
 }
 
 my $fileBase = File::Spec->join($outputDir, $filename);
-my @bisonCommand = ($bison, "-d", "-p", $symbolsPrefix, $grammarFilePath, "-o", "$fileBase.cpp");
+my @bisonCommand = ($bison, "--defines=$fileBase.h", "-p", $symbolsPrefix, $grammarFilePath, "-o", "$fileBase.cpp");
 push @bisonCommand, "--no-lines" if $^O eq "MSWin32"; # Work around bug in bison >= 3.0 on Windows where it puts backslashes into #line directives.
 system(@bisonCommand) == 0 or die;
-
-open HEADER, ">$fileBase.h" or die;
-print HEADER << "EOF";
-#ifndef CSSGRAMMAR_H
-#define CSSGRAMMAR_H
-EOF
-
-open HPP, "<$fileBase.cpp.h" or open HPP, "<$fileBase.hpp" or die;
-while (<HPP>) {
-    print HEADER;
-}
-close HPP;
-
-print HEADER "#endif\n";
-close HEADER;
-
-unlink("$fileBase.cpp.h");
-unlink("$fileBase.hpp");
-
diff -Naur a/Source/WebCore/platform/text/icu/UTextProvider.h b/Source/WebCore/platform/text/icu/UTextProvider.h
--- a/Source/WebCore/platform/text/icu/UTextProvider.h	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/WebCore/platform/text/icu/UTextProvider.h	2021-04-19 16:40:59.169942598 +0200
@@ -80,12 +80,12 @@
             // Ensure chunk offset is well formed if computed offset exceeds int32_t range.
             ASSERT(offset < std::numeric_limits<int32_t>::max());
             text->chunkOffset = offset < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(offset) : 0;
-            isAccessible = TRUE;
+            isAccessible = true;
             return true;
         }
         if (nativeIndex >= nativeLength && text->chunkNativeLimit == nativeLength) {
             text->chunkOffset = text->chunkLength;
-            isAccessible = FALSE;
+            isAccessible = false;
             return true;
         }
     } else {
@@ -94,12 +94,12 @@
             // Ensure chunk offset is well formed if computed offset exceeds int32_t range.
             ASSERT(offset < std::numeric_limits<int32_t>::max());
             text->chunkOffset = offset < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(offset) : 0;
-            isAccessible = TRUE;
+            isAccessible = true;
             return true;
         }
         if (nativeIndex <= 0 && !text->chunkNativeStart) {
             text->chunkOffset = 0;
-            isAccessible = FALSE;
+            isAccessible = false;
             return true;
         }
     }
diff -Naur a/Source/WebCore/platform/text/icu/UTextProviderLatin1.cpp b/Source/WebCore/platform/text/icu/UTextProviderLatin1.cpp
--- a/Source/WebCore/platform/text/icu/UTextProviderLatin1.cpp	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/WebCore/platform/text/icu/UTextProviderLatin1.cpp	2021-04-19 16:40:59.169942598 +0200
@@ -100,23 +100,23 @@
         if (index < uText->chunkNativeLimit && index >= uText->chunkNativeStart) {
             // Already inside the buffer. Set the new offset.
             uText->chunkOffset = static_cast<int32_t>(index - uText->chunkNativeStart);
-            return TRUE;
+            return true;
         }
         if (index >= length && uText->chunkNativeLimit == length) {
             // Off the end of the buffer, but we can't get it.
             uText->chunkOffset = static_cast<int32_t>(index - uText->chunkNativeStart);
-            return FALSE;
+            return false;
         }
     } else {
         if (index <= uText->chunkNativeLimit && index > uText->chunkNativeStart) {
             // Already inside the buffer. Set the new offset.
             uText->chunkOffset = static_cast<int32_t>(index - uText->chunkNativeStart);
-            return TRUE;
+            return true;
         }
         if (!index && !uText->chunkNativeStart) {
             // Already at the beginning; can't go any farther.
             uText->chunkOffset = 0;
-            return FALSE;
+            return false;
         }
     }
     
@@ -144,7 +144,7 @@
 
     uText->nativeIndexingLimit = uText->chunkLength;
 
-    return TRUE;
+    return true;
 }
 
 static int32_t uTextLatin1Extract(UText* uText, int64_t start, int64_t limit, UChar* dest, int32_t destCapacity, UErrorCode* status)
@@ -336,7 +336,7 @@
 static UBool uTextLatin1ContextAwareAccess(UText* text, int64_t nativeIndex, UBool forward)
 {
     if (!text->context)
-        return FALSE;
+        return false;
     int64_t nativeLength = uTextLatin1ContextAwareNativeLength(text);
     UBool isAccessible;
     if (uTextAccessInChunkOrOutOfRange(text, nativeIndex, nativeLength, forward, isAccessible))
@@ -356,7 +356,7 @@
         ASSERT(newContext == UTextProviderContext::PriorContext);
         textLatin1ContextAwareSwitchToPriorContext(text, nativeIndex, nativeLength, forward);
     }
-    return TRUE;
+    return true;
 }
 
 static int32_t uTextLatin1ContextAwareExtract(UText*, int64_t, int64_t, UChar*, int32_t, UErrorCode* errorCode)
diff -Naur a/Source/WebCore/platform/text/icu/UTextProviderUTF16.cpp b/Source/WebCore/platform/text/icu/UTextProviderUTF16.cpp
--- a/Source/WebCore/platform/text/icu/UTextProviderUTF16.cpp	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/WebCore/platform/text/icu/UTextProviderUTF16.cpp	2021-04-19 16:40:59.169942598 +0200
@@ -125,7 +125,7 @@
 static UBool uTextUTF16ContextAwareAccess(UText* text, int64_t nativeIndex, UBool forward)
 {
     if (!text->context)
-        return FALSE;
+        return false;
     int64_t nativeLength = uTextUTF16ContextAwareNativeLength(text);
     UBool isAccessible;
     if (uTextAccessInChunkOrOutOfRange(text, nativeIndex, nativeLength, forward, isAccessible))
@@ -145,7 +145,7 @@
         ASSERT(newContext == UTextProviderContext::PriorContext);
         textUTF16ContextAwareSwitchToPriorContext(text, nativeIndex, nativeLength, forward);
     }
-    return TRUE;
+    return true;
 }
 
 static int32_t uTextUTF16ContextAwareExtract(UText*, int64_t, int64_t, UChar*, int32_t, UErrorCode* errorCode)
diff -Naur a/Source/WebCore/platform/text/TextCodecICU.cpp b/Source/WebCore/platform/text/TextCodecICU.cpp
--- a/Source/WebCore/platform/text/TextCodecICU.cpp	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/WebCore/platform/text/TextCodecICU.cpp	2021-04-19 16:40:59.169942598 +0200
@@ -308,7 +308,7 @@
     m_converterICU = ucnv_open(m_canonicalConverterName, &err);
     ASSERT(U_SUCCESS(err));
     if (m_converterICU)
-        ucnv_setFallback(m_converterICU, TRUE);
+        ucnv_setFallback(m_converterICU, true);
 }
 
 int TextCodecICU::decodeToBuffer(UChar* target, UChar* targetLimit, const char*& source, const char* sourceLimit, int32_t* offsets, bool flush, UErrorCode& err)
diff -Naur a/Source/WTF/wtf/glib/GRefPtr.h b/Source/WTF/wtf/glib/GRefPtr.h
--- a/Source/WTF/wtf/glib/GRefPtr.h	2020-03-04 18:16:37.000000000 +0100
+++ b/Source/WTF/wtf/glib/GRefPtr.h	2021-04-19 18:30:15.524470841 +0200
@@ -29,8 +29,6 @@
 #include <wtf/RefPtr.h>
 #include <algorithm>
 
-extern "C" void g_object_unref(gpointer);
-extern "C" gpointer g_object_ref_sink(gpointer);
 
 namespace WTF {