Platform-interface.md

Componolit runtime platform interface

The Componolit runtime platform interface defines a linker interface the platform must provide. That interface can either be implemented in C using componolit_runtime.h or in Ada using componolit_runtime.ads. The table below shows the symbol names and language signatures to implement. Note that the Ada signatures are not ABI compatible to the C signatures. This has been done to simplify the support of native Ada platforms. The package Componolit_Runtime.C does the required conversions.

Symbol	C signature	Ada signature
componolit_runtime_log	void componolit_runtime_log(char *)	procedure Log (Msg : String)
componolit_runtime_raise_ada_exception	void componolit_runtime_raise_ada_exception(exception_t, char *, char*)	procedure Raise_Ada_Exception (T : Exception_Type; Name : String; Msg : String)
componolit_runtime_initialize	void componolit_runtime_initialize(void)	procedure Initialize
componolit_runtime_finalize	void componolit_runtime_finalize(void)	procedure Finalize

Symbol definitions

componolit_runtime_log

Signature

• C: void componolit_runtime_log(const char *)
• Ada: procedure Log (Msg : String)

• Msg: Log message

Semantics

Prints log message. Intended for debugging.

componolit_runtime_raise_ada_exception

Signature

• C: void componolit_runtime_raise_ada_exception(exception_t, char *, char*)
• Ada: procedure Raise_Ada_Exception(T : Exception_Type; Name : String; Msg : String)

• T: Type of the exception (enum)
• Name: Name of the raised exception (or short description)
• Msg: Exception message

Semantics

Called when any exception is raised. The Name is usually the name of the Ada exception or a short description of it. In this runtime Msg consists of the file name and line number of the exception occurrence.

componolit_runtime_initialize

Signature

• C: void componolit_runtime_initialize(void)
• Ada: procedure Initialize

Semantics

Called in adainit when the runtime gets initialized by the binder. Implementation can be empty.

componolit_runtime_finalize

Signature

• C: void componolit_runtime_finalize(void)
• Ada: procedure Finalize

Semantics

Called in adafinal when the runtime is finalized by the binder. Implementation can be empty.

Other symbols

When porting the runtime to a platform ther can be other missing symbols, often starting with __gnat_. These are functions inserted by the compiler for memory management and exception handling. As they are highly platform dependent and are not required by the runtime code to work they are not listed here.