--- gcc/objc/README 2018/04/24 18:10:14 1.1 +++ gcc/objc/README 2018/04/24 18:26:43 1.1.1.4 @@ -1,11 +1,10 @@ -GNU Objective C release notes for gcc 2.4 -***************************************** +GNU Objective C notes +********************* -Since gcc 2.3.3 the Objective C as part of gcc has changed a lot. -This document is to explain what has been done, and a little about -how specific features differ from other implementations. The runtime -has been completely rewritten. The earlier runtime had several +This document is to explain what has been done, and a little about how +specific features differ from other implementations. The runtime has +been completely rewritten in gcc 2.4. The earlier runtime had several severe bugs and was rather incomplete. The compiler has had several new features added as well. @@ -16,22 +15,22 @@ who knows Objective C from somewhere els Runtime API functions ===================== -The runtime is moddeled after the NeXT Objective C runtime. That is, -most functions have semanthics as it is known from the NeXT. The +The runtime is modeled after the NeXT Objective C runtime. That is, +most functions have semantics as it is known from the NeXT. The names, however, have changed. All runtime API functions have names of lowercase letters and and underscores as opposed to the `traditional' mixed case names. The runtime api functions are not documented as of now. Someone offered to write it, and did it, but we were not allowed to use it by his university (Very sad story). We have started writing -the documentation over again. This will be announced appropriate -places when it becomes avilable. +the documentation over again. This will be announced in appropriate +places when it becomes available. Protocols ========= -Protocols are now fully supported. The semanthics is exactly as on the +Protocols are now fully supported. The semantics is exactly as on the NeXT. There is a flag to specify how protocols should be typechecked when adopted to classes. The normal typechecker requires that all methods in a given protocol must be implemented in the class that @@ -51,7 +50,7 @@ never if no methods of that particular c Besides this, it is allowed to have several +initialize methods, one for each category. The order in which these (multiple methods) are called is not well defined. I am not completely certain what the -semathics of this method is for other implementations, but this is +semantics of this method is for other implementations, but this is how it works for GNU Objective C. @@ -62,26 +61,14 @@ This is supported in the style of NeXT T headerfile Typedstreams.h for api functions. I (Kresten) have rewritten it in Objective C, but this implementation is not part of 2.4, it is available from the GNU Objective C prerelease archive. - There is one semathic difference worth noting concerning objects -stored with objc_write_object_reference (aka NXWriteObjectReference). -When these are read back in, their object is not guaranteed to be -available until the `-awake' method is called in the object that -requests that object. To objc_read_object you must pass a pointer to -an id, which is valid after exit from the function calling it (like -e.g. an instance variable). In general, you should not use objects -read in until the -awake method is called. - - -argframe manipulation -===================== - -performv:: will not work properly on all targets. A primitive -heuristics is included which tries to determine if and how it should -be done. You will get a warning when compiling `objc-msg.c' if the -euristics doesn't work. - Currently there is no notion of the marg_... macros available on the -NeXT. That is, the arguments to forward:: can only be used to apply -the arguments in the stylle of performv::. We are working on this. + There is one difference worth noting concerning objects stored with +objc_write_object_reference (aka NXWriteObjectReference). When these +are read back in, their object is not guaranteed to be available until +the `-awake' method is called in the object that requests that object. +To objc_read_object you must pass a pointer to an id, which is valid +after exit from the function calling it (like e.g. an instance +variable). In general, you should not use objects read in until the +-awake method is called. Acknowledgements @@ -103,14 +90,6 @@ Steve Naroff and Rich in the compiler. -Prerelease Archive -================== - -Intermediate releases, bugfixes and additional other information of -the GNU Objective C will be available from iesd.auc.dk in the -directory /pub/ObjC. - - Bug Reports ===========