Cherry-pick 266322@main (8e28343). https://bugs.webkit.org/show_bug.c…

…gi?id=258517

    Source/JavaScriptCore/CMakeLists.txt: ensure reproducibility of __TIMESTAMP__
    https://bugs.webkit.org/show_bug.cgi?id=258517

    Reviewed by Michael Catanzaro.

    __TIMESTAMP__ refers to mtime of the file that contains it, which is unstable
    and breaks binary reproducibility when the file is generated at build time. To ensure
    this does not happen, mtime should be set from the original file.

    * Source/JavaScriptCore/CMakeLists.txt:

    Canonical link: https://commits.webkit.org/266322@main

Source/JavaScriptCore/CMakeLists.txt

@@ -155,13 +155,24 @@ list(APPEND JavaScriptCore_SOURCES
     ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBuiltins.cpp
 )
 
-add_custom_command(
-    OUTPUT ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
-    MAIN_DEPENDENCY ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in
-    COMMAND ${PERL_EXECUTABLE} -pe s/CACHED_TYPES_CKSUM/__TIMESTAMP__/ ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in > ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
+find_program(TOUCH_EXECUTABLE touch)
+if (TOUCH_EXECUTABLE)
+    add_custom_command(
+        OUTPUT ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
+        MAIN_DEPENDENCY ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in
+        COMMAND ${PERL_EXECUTABLE} -pe s/CACHED_TYPES_CKSUM/__TIMESTAMP__/ ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in > ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
+        COMMAND ${TOUCH_EXECUTABLE} -r ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
             VERBATIM
-)
-
+    )
+else ()
+    message(WARNING "Unable to find touch executable; ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp is built non-reproducibly from ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in")
+    add_custom_command(
+        OUTPUT ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
+        MAIN_DEPENDENCY ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in
+        COMMAND ${PERL_EXECUTABLE} -pe s/CACHED_TYPES_CKSUM/__TIMESTAMP__/ ${JAVASCRIPTCORE_DIR}/runtime/JSCBytecodeCacheVersion.cpp.in > ${JavaScriptCore_DERIVED_SOURCES_DIR}/JSCBytecodeCacheVersion.cpp
+            VERBATIM
+    )
+endif ()
 
 set(JavaScriptCore_FRAMEWORKS
     WTF