++ed by:
MHOWARD DMOL FAYLAND BEROV ILUX

7 PAUSE users
4 non-PAUSE users.

Yuki Kimoto
and 1 contributors

NAME

SPVM::Document::Extension - C/C++ Binding using SPVM Extension(BETA before 1.0)

Tutorial

Runtime Compile Native Function

If you use the feature Runtime Compile Native Function, you can write program using C language in runtime. This is similar with Extension::C, but SPVM implement this feature by default.

  # SPVM/TestCase/Extension.spvm
  package TestCase::Extension {
    native sub sum : int ($num1 : int, $num2 : int);
  }
  
  // SPVM/TestCase/Extension.native/Extension.c
  #include <spvm_api.h>
  
  int32_t SPVM__TestCase__Extension__sum(SPVM_API* api, SPVM_API_VALUE* args) {
    
    int32_t total = args[0].int_value + args[1].int_value;
    
    return total;
  }

At first, you specify native descripter at SPVM subroutine.

  package TestCase::Extension {
    # native descripter
    native sub sum : int ($num1 : int, $num2 : int);
  }

Next, you create "SPVM/TestCase/Extension/Extension.c" file

  SPVM/TestCase/Extension.spvm
  SPVM/TestCase/Extension.native/Extension.c

Next, you write C language. You include spvm_api.h.

  #include <spvm_api.h>

C Function name must be replace : with <_> and add SPVM__ to top of SPVM subroutine name. SPVM subroutine absolute name is TestCase::Extension::sum. C function name is SPVM__TestCase__Extension__sum.

  int32_t SPVM__TestCase__Extension__sum(SPVM_API* api, SPVM_API_VALUE* args) {

    int32_t total = args[0].int_value + args[1].int_value;
    
    return total;
  }

First argument is api. This is the pointer to SPVM_API. Second argument is args. This is array of SPVM_API_VALUE.

SPVM_API_VALUE is union of C language. If you want to get int value, you do the followng.

  args[0].int_value

You can get all type of value by the following member.

  args[0].byte_value
  args[0].short_value
  args[0].int_value
  args[0].long_value
  args[0].float_value
  args[0].double_value
  args[0].object_value

Type of return value is corresponding the folloing type.

  [SPVM]              [C]
  byte                int8_t
  short               int16_t
  int                 int32_t
  long                int64_t
  float               float
  double              double
  [Object value]      SPVM_API_OBJECT*