collect-heap-utilization-by-class causes heap corruption

[svspire]

(ccl::heap-utilization :gc-first nil :classes t)

causes heap corruption, at least in the CCL IDE.

Test:

Do the above form in the OSX IDE, then meta-dot on some form that has a definition. You'll either get a cryptic Cocoa error: "Objective-C runtime exception: typeForContentsOfURL:error: must be overridden for your application to support non-'file:' URLs."

Or you get a "Definitions" window that's about 1 inch square and cannot be expanded.

Or you get an error in the AltConsole?:

Error: The value #<A Null Foreign Pointer> is not of the expected type FIXNUM. While executing: CCL::ID-MAP-FREE-OBJECT, in process Initial(0). Type :POP to abort, :R for a list of available restarts. Type :? for other options.

Sometimes you might have to execute the form more than once to see an error. This is not a new bug; it happens with 1.12-dev-r16695M-trunk and much older versions of CCL/IDE in both 32-bit and 64-bit mode.

EGC enabled or not makes no difference.

(ccl::heap-utilization :gc-first nil :classes nil) causes no such corruption.

[svspire]

I've narrowed this down enough to know that the hash table operations in #'collect-heap-utilization-by-class are probably not the culprit. But commenting out the call to #'class-of (and assigning the "class" local variable to e.g. #.(find-class 'input-stream)) does solve the problem.