| 68 | | A reference to standard library files is here: http://www.utas.edu.au/infosys/info/documentation/C/CStdLib.html |
| 69 | | |
| 70 | | Special functions that are currently included in the grammar can instead be treated just like any other function and "linked in" at a later stage. This will simplify the grammar and front-end. Functions that can be removed include {{{send}}}, {{{recv}}}, {{{allocate}}}, {{{deallocate}}}. |
| 71 | | |
| 72 | | When {{{ModelIF.complete}}} is invoked, it will look for functions which are called but not defined. It will then look through a standard library for a function of the correct name, and add that function to the process containing the call. |
| 73 | | |
| 74 | | Note: {{{allocate}}} takes a type argument, so we should also add to the grammar a new expression {{{sizeof(type)}}}. The semantics module will associate a special symbolic constant to this expression, corresponding to the type (e.g., {{{SIZEOF_INT}}}). We can then replace our {{{allocate}}} and {{{deallocate}}} with the standard C functions {{{malloc}}} and {{{free}}} |
| 75 | | |
| 76 | | |
| 77 | | Some libraries add state: shared state and process global state. How do manage this? |
| 78 | | |
| 79 | | When a library is included into a model, it may add shared variables to the model. When it is attached to a process it may add process-global variables. |
| 80 | | |
| 81 | | Define class Library, LibraryFunction. |
| 82 | | |
| 83 | | attachToModel(ModelIF); |
| 84 | | attachToProcess(ProcessIF); |
| 85 | | |
| 86 | | in ModelIF, ProcessIF, etc.: getFunctionWithName("fprintf") will return the function if it has been added. |
| 87 | | |
| 88 | | FunctionIF: boolean field: isSystemFunction. If true, function does not have body (locations). Instead, a special class will be loaded to execute this function's transformation of the state when it is invoked. |
| 89 | | |
| 90 | | add module library, submodule of model. |
| 91 | | |
| 92 | | In the library module, there should be a LibraryLoader class and a LibraryIF. The LibraryLoader will have a method loadLibrary(String name) that returns a LibraryIF. The loader should contain information about each of the implemented libraries. The loadLibrary() method will check for a library with the matching name, return it if available, or throw an exception. |
| 93 | | |
| 94 | | {{{ |
| 95 | | public class LibraryLoader { |
| 96 | | LibraryIF loadLibrary(String name); |
| 97 | | } |
| 98 | | |
| 99 | | public interface LibraryIF { |
| 100 | | String name(); |
| 101 | | |
| 102 | | Map<String, SharedVariableIF> getConstants(); |
| 103 | | |
| 104 | | /* Returns the regular (non-system) functions */[[BR]] |
| 105 | | List<FunctionDeclaration> getFunctions(); |
| 106 | | |
| 107 | | /* Gives the syntax for system functions */[[BR]] |
| 108 | | Map<String, FunctionDeclaration> getSystemFunctions(); |
| 109 | | } |
| 110 | | }}} |
| 111 | | |
| 112 | | A Program should have information on its included libraries, and have a method to get that information. |
| 113 | | |
| 114 | | {{{ |
| 115 | | List<String> libraries(); |
| 116 | | |
| 117 | | ModelBuilder will need to process libraries by loading each and adding the appropriate components to the model. |
| 118 | | |
| 119 | | void processLibraries(ModelIF model, List<String> libraries); |
| 120 | | |
| 121 | | We also need to keep track of system functions vs regular functions, and which libraries the system functions come from. |
| 122 | | |
| 123 | | public interface SystemFunctionIF extends FunctionIF { |
| 124 | | String libraryName(); |
| 125 | | |
| 126 | | } |
| 127 | | }}} |
| 128 | | |
| 129 | | also add system level function definition in semantics, next to !Executor. |
| 130 | | |
| 131 | | If all system functions are part of a library, the `execute()` method in the executor should be: |
| 132 | | |
| 133 | | {{{ |
| 134 | | void execute(EnvironmentIF environment, InvocationStatementIF statement); |
| 135 | | }}} |
| 136 | | |
| 137 | | This method will instantiate the appropriate `LibraryExecutor` for the `SystemFunctionIF`, then call a method in that library executor to execute the appropriate function. |
| 138 | | |
| 139 | | {{{ |
| 140 | | public interface LibraryExecutorIF { |
| 141 | | void execute(EnvironmentIF environment, InvocationStatementIF invocation); |
| 142 | | |
| 143 | | boolean containsFunction(String name); |
| 144 | | } |
| 145 | | }}} |
