Expose compile time constants in metadata as JSCode

[ivanbuhov]

All compile time constants are exposed as variables and we are trying to retrive their values at runtime. This crashes the runtime because these variables doesn't exist at runtime. Example of such variable is NSNotFound in iOS 9:

static const NSInteger NSNotFound = NSIntegerMax;

A possible solution is in metadata generation process to retrieve the value of the variable and save it as JSCodeMeta. This way we will no longer search for non-existing values at runtime.

It can be tricky to handle all variable types e.g. numerics, string, char, structs etc.

[jasssonpet]

Here is an incomplete list of some static const variables :)

static const CFIndex kCFNotFound = -1;
static const CGFontIndex kCGFontIndexInvalid = ((1 << 16) - 1);
static const CGFontIndex kCGFontIndexMax = ((1 << 16) - 2);
static const CGFontIndex kCGGlyphMax = kCGFontIndexMax;
static const Float64 kAudioStreamAnyRate = 0.0;
static const MIDIObjectType kMIDIObjectType_ExternalMask = (MIDIObjectType)0x10;
static const NSExpressionType NSFetchRequestExpressionType = (NSExpressionType)50;
static const NSInteger NSNotFound = NSIntegerMax;
static const NSInteger NSOperationQueueDefaultMaxConcurrentOperationCount = -1;
static const NSPointerFunctionsOptions NSHashTableCopyIn = NSPointerFunctionsCopyIn;
static const NSPointerFunctionsOptions NSHashTableObjectPointerPersonality = NSPointerFunctionsObjectPointerPersonality;
static const NSPointerFunctionsOptions NSHashTableStrongMemory = NSPointerFunctionsStrongMemory;
static const NSPointerFunctionsOptions NSHashTableWeakMemory = NSPointerFunctionsWeakMemory;
static const NSPointerFunctionsOptions NSHashTableZeroingWeakMemory = NSPointerFunctionsZeroingWeakMemory;
static const NSPointerFunctionsOptions NSMapTableCopyIn = NSPointerFunctionsCopyIn;
static const NSPointerFunctionsOptions NSMapTableObjectPointerPersonality = NSPointerFunctionsObjectPointerPersonality;
static const NSPointerFunctionsOptions NSMapTableStrongMemory = NSPointerFunctionsStrongMemory;
static const NSPointerFunctionsOptions NSMapTableWeakMemory = NSPointerFunctionsWeakMemory;
static const NSPointerFunctionsOptions NSMapTableZeroingWeakMemory = NSPointerFunctionsZeroingWeakMemory;
static const NSUInteger NSUndoCloseGroupingRunLoopOrdering = 350000;
static const PHAssetResourceDataRequestID PHInvalidAssetResourceDataRequestID = 0;
static const PHImageRequestID PHInvalidImageRequestID = 0;
static const UILayoutPriority UILayoutPriorityDefaultHigh = 750;
static const UILayoutPriority UILayoutPriorityDefaultLow = 250;
static const UILayoutPriority UILayoutPriorityFittingSizeLevel = 50;
static const UILayoutPriority UILayoutPriorityRequired = 1000;

[ivanbuhov]

@jasssonpet very good regex skills, your list is missing only 2 constants ;)

[jasssonpet]

Are these in usr/include? I didn't search there.

[ivanbuhov]

Yes, the constants are OS_ACTIVITY_FLAG_DEFAULT and OS_ACTIVITY_FLAG_DETACHED from usr/include/os/activity.h.

[ivanbuhov]

Fixed: #329