72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/*
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* $Id: context.c,v 1.4 2005-05-19 16:41:10 bacon Exp $
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*/
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#include <xp/stx/context.h>
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#include <xp/stx/object.h>
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#define XP_STX_CONTEXT_SIZE 4
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#define XP_STX_CONTEXT_IP 0
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#define XP_STX_CONTEXT_METHOD 1
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#define XP_STX_CONTEXT_ARGUMENTS 2
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#define XP_STX_CONTEXT_TEMPORARIES 3
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xp_stx_word_t xp_stx_new_context (xp_stx_t* stx,
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xp_stx_word_t method, xp_stx_word_t args, xp_stx_word_t temp)
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{
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xp_stx_word_t context;
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context = xp_stx_alloc_object(stx,XP_STX_CONTEXT_SIZE);
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XP_STX_CLASS(stx,context) = stx->class_context;
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XP_STX_AT(stx,context,XP_STX_CONTEXT_IP) = XP_STX_TO_SMALLINT(0);
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XP_STX_AT(stx,context,XP_STX_CONTEXT_METHOD) = method;
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XP_STX_AT(stx,context,XP_STX_CONTEXT_ARGUMENTS) = args;
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XP_STX_AT(stx,context,XP_STX_CONTEXT_TEMPORARIES) = temp;
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return context;
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}
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static xp_stx_byte_t __fetch_byte (xp_stx_t* stx, xp_stx_word_t context)
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{
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xp_stx_word_t method, ip;
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ip = XP_STX_AT(stx,context,XP_STX_CONTEXT_IP);
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method = XP_STX_AT(stx,context,XP_STX_CONTEXT_METHOD);
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/* increment instruction pointer */
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XP_STX_AT(stx,context,XP_STX_CONTEXT_IP) =
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XP_STX_TO_SMALLINT((XP_STX_FROM_SMALLINT(ip) + 1));
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return XP_STX_BYTEAT(stx,method,XP_STX_FROM_SMALLINT(ip));
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}
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int xp_stx_run_context (xp_stx_t* stx, xp_stx_word_t context)
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{
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xp_stx_byte_t byte, operand;
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while (!stx->__wantabort) {
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/* check_process_switch (); // hopefully */
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byte = __fetch_byte (stx, context);
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#ifdef _DOS
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printf (XP_TEXT("code: %x\n"), byte);
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#else
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xp_printf (XP_TEXT("code: %x\n"), byte);
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#endif
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switch (byte) {
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case PUSH_OBJECT:
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operand = __fetch_byte (stx, context);
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break;
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case SEND_UNARY_MESSAGE:
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operand = __fetch_byte (stx, context);
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break;
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case HALT:
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goto exit_run_context;
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}
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}
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exit_run_context:
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return 0;
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}
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