134322 2014-06-25 18:09:49 -0700 After r170428, offline assembler sometimes creates empty LLIntAssembly.h 2014-06-26 17:32:57 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) All All RESOLVED INVALID P2 Normal --- 1 msaboff msaboff peavo simon.fraser oldest_to_newest 1018472 0 msaboff 2014-06-25 18:09:49 -0700 After r170428, the offline assembler will sometimes create an LLIntAssembly.h file with just the hash line: // offlineasm input hash: cb3be4a5c6bc8076a46396599fba7c070d00cdf8 1fdc12e5c4851899db57a32e840ba77f46a9fa29 283b8172f1ff6e5e115dbe22d5c7494f289ea2da 1018649 1 peavo 2014-06-26 09:48:25 -0700 This is just a guess, but could it be caused by an exception being thrown, caused by for example the change in asm.rb? --- Source/JavaScriptCore/offlineasm/asm.rb (revision 170426) +++ Source/JavaScriptCore/offlineasm/asm.rb (working copy) @@ -262,7 +262,7 @@ class Assembler @codeOrigin = nil @commentState = :many when :many - @outp.puts "// #{text}" if $enableCodeOriginComments + @outp.puts $commentPrefix + " #{text}" if $enableCodeOriginComments else raise end 1018816 2 msaboff 2014-06-26 17:32:57 -0700 I can no longer get this to fail. When I filed, I performed the following steps: svn up -r 170424 Tools/Scripts/build-webkit --debug svn up -r 170431 Tools/Scripts/build-webkit --debug The second build failed. Today, those steps work fine. I tried multiple times, but can't reproduce. We can file another bug if the problem reappears.