![]() They are the same as their Objective-C equivalents, except that they use the class rather than objcclass keyword. These do not exist in Java, but can be required to solve problems with circular references amongst Java classes. While dotted unit names are not supported, a (global) namespace directive can be used to tell the compiler to put all definitions in the current unit under the specified Java package name. Bitpacking, or indeed any other kind of feature that influences the data layout ( directive.Support may be added in the future, since they are very similar to records. General language features information Unsupported language features This behaviour is only guaranteed at the purely semantic level, and not in any way in terms of absolute or relative performance. Any language feature not mentioned below can be expected to behave the same as it does on native FPC targets (except for accidental omissions). While the language supported by the JVM port is as close as possible to the one supported for native FPC targets, there are some differences due to the nature of the JVM platform. The extended floating point type maps to double, just like it does on other targets that do not support native 80 bits floating point support. array indices are always 32 bit in the JVM. ![]() 32 bit arithmetic can be expressed more efficiently in Java bytecode than 64 bit arithmetic.The generated code will still run perfectly on 64 bit JVMs, and the compiler will also use the built-in 64 bit arithmetic opcodes of the JVM when performing 64 bit computations. This only means that arithmetic expressions are by default evaluated using 32 bit arithmetic, rather than by 64 bit arithmetic, just like for native 32 bit targets. Internally the Java/JVM target is treated by the compiler as a 32 bit target. Nevertheless, all identifiers used below will appear using their fully qualified Java name, since the Pascal name can be derived from that while the opposite is not the case. For classes or other types declared in Pascal source code, the regular unit.identifier syntax works. All Pascal headers generated for imported classes abbreviate class names by taking the first letter of each part of the package name, followed by the full class name (e.g., becomes JLObject). This means that it is not possible to use identifiers such as in the source code. fully qualified class names: the compiler currently does not support namespaces (such as org.freepascal or java.lang) as a syntactic element, nor does it support dotted unit names.While possibly counterintuitive, this means that variables of such types can actually be made to behave more like their counterparts on native targets than other types. This means that they are implicitly pointers to the actual data, since a class or array is also just a pointer in Java. implicit pointer types: a number of types that are not pointers in Pascal, are implemented on top of Java classes or arrays.A number of features are only available when programming in Pascal, because the Java language has no similar concept. on the Pascal side/ on the Java side: refers to code written in resp.The minimum JDK version required for running programs generated by the FPC JVM port is 1.5. The reason is probably not so much that it is written in Java, but simply that it is quite a slow program. The reason is that the used Java assembler, Jasmin, is very slow. That is however not the goal of this initial port and bug reports about missing unit-level functionality are not useful at this point (but patches are of course welcome! :).Ĭompiling code for the JVM target is currently quite slow. Over time, it is possible to implement most of the standard RTL and other unit functionality in a way that it can be compiled using the JVM-targeted compiler. Furthermore, even the system unit is quite limited in terms of the functionality that it provides (details are below). That means that except for the system unit and a unit that imports the JDK classes, no other standard RTL or other units are available. 4.2.4.2 Ansistring and shortstring code page.4.2 Specific language features information.4.1.2 Partially supported language features.4.1 General language features information.
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