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/*

    		 Crown Copyright (c) 1997

    This TenDRA(r) Computer Program is subject to Copyright

    owned by the United Kingdom Secretary of State for Defence

    acting through the Defence Evaluation and Research Agency

    (DERA).  It is made available to Recipients with a

    royalty-free licence for its use, reproduction, transfer

    to other parties and amendment for any purpose not excluding

    product development provided that any such use et cetera

    shall be deemed to be acceptance of the following conditions:-

        (1) Its Recipients shall ensure that this Notice is

        reproduced upon any copies or amended versions of it;

        (2) Any amended version of it shall be clearly marked to

        show both the nature of and the organisation responsible

        for the relevant amendment or amendments;

        (3) Its onward transfer from a recipient to another

        party shall be deemed to be that party's acceptance of

        these conditions;

        (4) DERA gives no warranty or assurance as to its

        quality or suitability for any purpose and DERA accepts

        no liability whatsoever in relation to any use to which

        it may be put.

*/

#include "config.h"

#include "version.h"

#include "c_types.h"

#include "exp_ops.h"

#include "type_ops.h"

#include "error.h"

#include "tdf.h"

#include "allocate.h"

#include "basetype.h"

#include "capsule.h"

#include "chktype.h"

#include "compile.h"

#include "destroy.h"

#include "diag.h"

#include "encode.h"

#include "exception.h"

#include "exp.h"

#include "init.h"

#include "inttype.h"

#include "shape.h"

#include "statement.h"

#include "stmt.h"

#include "struct.h"

#include "syntax.h"

#include "throw.h"

#include "tok.h"

#include "typeid.h"

#include "ustring.h"

#if TDF_OUTPUT

/*

    ENCODE THE ADDRESS OF A DESTRUCTOR

    This routine adds the address of the destructor function corresponding

    to d to the bitstream bs.

*/

BITSTREAM *enc_destr_func

    PROTO_N ( ( bs, d ) )

    PROTO_T ( BITSTREAM *bs X EXP d )

{

    if ( !IS_NULL_exp ( d ) ) {

	EXP f ;

	while ( IS_exp_nof ( d ) ) {

	    d = DEREF_exp ( exp_nof_pad ( d ) ) ;

	}

	f = DEREF_exp ( exp_destr_call ( d ) ) ;

	if ( IS_exp_func_id ( f ) ) {

	    ulong n ;

	    IDENTIFIER fn = DEREF_id ( exp_func_id_id ( f ) ) ;

	    IGNORE capsule_id ( fn, VAR_tag ) ;

	    n = unit_no ( bs, fn, VAR_tag, 0 ) ;

	    ENC_obtain_tag ( bs ) ;

	    ENC_make_tag ( bs, n ) ;

	    return ( bs ) ;

	}

    }

    ENC_make_null_proc ( bs ) ;

    return ( bs ) ;

}

/*

    EXCEPTION HANDLING ROUTINES

    The exception handling routines are only included in the C++ producer.

*/

#if LANGUAGE_CPP

/*

    ENCODE A CATCH STATEMENT

    This routine adds the start of a catch statement to the bitstream bs.

    It checks whether the type t can handle the current exception.  If

    the label lab is given then catching the exception causes a jump to

    lab.  Otherwise the handler body, consisting of seq statements,

    followed by the code if the exception is not caught, needs to be

    added later.

*/

static BITSTREAM *enc_catch

    PROTO_N ( ( bs, t, lab, seq ) )

    PROTO_T ( BITSTREAM *bs X TYPE t X ulong lab X unsigned seq )

{

    BITSTREAM *ts ;

    NTEST tst = ntest_eq ;

    if ( lab == LINK_NONE ) {

	/* Create label if necessary */

	lab = unit_no ( bs, NULL_id, VAR_label, 1 ) ;

	ENC_conditional ( bs ) ;

	ENC_make_label ( bs, lab ) ;

	ENC_SEQUENCE ( bs, seq ) ;

	tst = ntest_not_eq ;

    }

    ENC_integer_test ( bs ) ;

    ENC_OFF ( bs ) ;

    bs = enc_ntest ( bs, tst ) ;

    ENC_make_label ( bs, lab ) ;

    bs = enc_special ( bs, TOK_except_catch ) ;

    ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

    ts = enc_rtti_type ( ts, t, lex_typeid ) ;

    bs = enc_bitstream ( bs, ts ) ;

    bs = enc_make_int ( bs, type_sint, 0 ) ;

    return ( bs ) ;

}

/*

    ENCODE THE START OF A TRY BLOCK

    This routine adds the start of a try block to the bitstream bs.  seq

    gives the number of statements to follow.

*/

BITSTREAM *enc_try_start

    PROTO_N ( ( bs, pn, seq ) )

    PROTO_T ( BITSTREAM *bs X ulong *pn X unsigned seq )

{

    ulong n ;

    ulong lab ;

    BITSTREAM *ts ;

    /* Must be in a function definition */

    if ( in_dynamic_init ) output_init = 1 ;

    /* Encode the try block jump buffer */

    n = unit_no ( bs, NULL_id, VAR_tag, 1 ) ;

    ENC_variable ( bs ) ;

    bs = enc_access ( bs, crt_func_access ) ;

    ENC_make_tag ( bs, n ) ;

    ENC_make_value ( bs ) ;

    bs = enc_special ( bs, TOK_try_type ) ;

    *pn = n ;

    /* Encode the try block label */

    lab = unit_no ( bs, NULL_id, VAR_label, 1 ) ;

    ENC_conditional ( bs ) ;

    ENC_make_label ( bs, lab ) ;

    /* Encode the try block body */

    ENC_SEQUENCE ( bs, seq ) ;

    bs = enc_special ( bs, TOK_try_begin ) ;

    ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

    ENC_obtain_tag ( ts ) ;

    ENC_make_tag ( ts, n ) ;

    ENC_current_env ( ts ) ;

    ENC_make_local_lv ( ts ) ;

    ENC_make_label ( ts, lab ) ;

    bs = enc_bitstream ( bs, ts ) ;

    return ( bs ) ;

}

/*

    ENCODE THE END OF A TRY BLOCK

    This routine adds the end of the current try block to the bitstream bs.

*/

BITSTREAM *enc_try_end

    PROTO_N ( ( bs, n ) )

    PROTO_T ( BITSTREAM *bs X ulong n )

{

    BITSTREAM *ts ;

    bs = enc_special ( bs, TOK_try_end ) ;

    ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

    ENC_obtain_tag ( ts ) ;

    ENC_make_tag ( ts, n ) ;

    bs = enc_bitstream ( bs, ts ) ;

    return ( bs ) ;

}

/*

    ENCODE A TRY BLOCK

    This routine adds the try block e to the bitstream bs.

*/

BITSTREAM *enc_try

    PROTO_N ( ( bs, e ) )

    PROTO_T ( BITSTREAM *bs X EXP e )

{

    int uc ;

    ulong ex ;

    unsigned seq ;

    EXP a = DEREF_exp ( exp_try_block_body ( e ) ) ;

    LIST ( EXP ) p = DEREF_list ( exp_try_block_handlers ( e ) ) ;

    LIST ( TYPE ) q = DEREF_list ( exp_try_block_htypes ( e ) ) ;

    EXP c = DEREF_exp ( exp_try_block_ellipsis ( e ) ) ;

    /* Ignore handlers if exception handling disabled */

    if ( !output_except ) {

	bs = enc_stmt ( bs, a ) ;

	return ( bs ) ;

    }

    /* Encode the try block */

    no_destructors++ ;

    if ( output_new_diag ) {

	seq = 2 ;

    } else {

	seq = stmt_length ( a ) + 1 ;

    }

    bs = enc_try_start ( bs, &ex, seq ) ;

    COPY_ulong ( exp_try_block_no ( e ), ex ) ;

    if ( output_new_diag ) {

	BITSTREAM *ts = enc_diag_begin ( &bs ) ;

	ts = enc_stmt ( ts, a ) ;

	bs = enc_diag_end ( bs, ts, e, 1 ) ;

    } else {

	bs = enc_compound_stmt ( bs, a ) ;

    }

    bs = enc_try_end ( bs, ex ) ;

    uc = unreached_code ;

    /* Encode the handlers */

    while ( !IS_NULL_list ( p ) ) {

	EXP b = DEREF_exp ( HEAD_list ( p ) ) ;

	TYPE t = DEREF_type ( HEAD_list ( q ) ) ;

	unreached_code = 0 ;

	if ( !output_new_diag ) {

	    b = DEREF_exp ( exp_handler_body ( b ) ) ;

	}

	seq = stmt_length ( b ) + 1 ;

	bs = enc_catch ( bs, t, LINK_NONE, seq ) ;

	bs = enc_compound_stmt ( bs, b ) ;

	bs = enc_special ( bs, TOK_except_end ) ;

	if ( !unreached_code ) uc = 0 ;

	q = TAIL_list ( q ) ;

	p = TAIL_list ( p ) ;

    }

    /* Encode the default handler */

    unreached_code = 0 ;

    if ( IS_exp_handler ( c ) ) {

	if ( !output_new_diag ) {

	    c = DEREF_exp ( exp_handler_body ( c ) ) ;

	}

	seq = stmt_length ( c ) ;

	if ( seq ) {

	    ENC_SEQUENCE ( bs, seq ) ;

	    bs = enc_compound_stmt ( bs, c ) ;

	}

	bs = enc_special ( bs, TOK_except_end ) ;

    } else {

	/* Re-throw current exception */

	bs = enc_exp ( bs, c ) ;

    }

    if ( !unreached_code ) uc = 0 ;

    unreached_code = uc ;

    no_destructors-- ;

    return ( bs ) ;

}

/*

    RETHROW THE CURRENT EXCEPTION

    This routine adds the expression 'throw' to the bitstream bs.

*/

BITSTREAM *enc_rethrow

    PROTO_N ( ( bs ) )

    PROTO_T ( BITSTREAM *bs )

{

    if ( output_except ) {

	bs = enc_special ( bs, TOK_except_rethrow ) ;

    } else {

	BITSTREAM *ts ;

	bs = enc_special ( bs, TOK_except_bad ) ;

	ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

	ts = enc_make_snat ( ts, 0 ) ;

	bs = enc_bitstream ( bs, ts ) ;

    }

    unreached_code = 1 ;

    return ( bs ) ;

}

/*

    ENCODE A THROW EXPRESSION

    This routine adds the expression 'throw a' to the bitstream bs.  If

    a is the null expression then the current exception is rethrown.  b

    and d give the size and destructor for the exception type.

*/

BITSTREAM *enc_throw

    PROTO_N ( ( bs, a, b, d ) )

    PROTO_T ( BITSTREAM *bs X EXP a X EXP b X EXP d )

{

    if ( !IS_NULL_exp ( a ) && output_except ) {

	/* Set up variable */

	EXP c ;

	BITSTREAM *ts, *us ;

	TYPE t = DEREF_type ( exp_type ( a ) ) ;

	ulong n = unit_no ( bs, NULL_id, VAR_tag, 1 ) ;

	ENC_variable ( bs ) ;

	bs = enc_access ( bs, dspec_none ) ;

	ENC_make_tag ( bs, n ) ;

	MAKE_exp_dummy ( t, NULL_exp, n, NULL_off, 2, c ) ;

	/* Allocate space for exception value */

	bs = enc_special ( bs, TOK_from_ptr_void ) ;

	ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

	ts = enc_alignment ( ts, t ) ;

	ts = enc_special ( ts, TOK_except_alloc ) ;

	us = start_bitstream ( NIL ( FILE ), ts->link ) ;

	us = enc_exp ( us, b ) ;

	ts = enc_bitstream ( ts, us ) ;

	bs = enc_bitstream ( bs, ts ) ;

	/* Assign exception value */

	ENC_SEQ_SMALL ( bs, 1 ) ;

	bs = enc_init_tag ( bs, n, NULL_off, 1, t, a, NULL_exp, 0 ) ;

	/* Throw the exception */

	bs = enc_special ( bs, TOK_except_throw ) ;

	ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

	ts = enc_special ( ts, TOK_to_ptr_void ) ;

	us = start_bitstream ( NIL ( FILE ), ts->link ) ;

	us = enc_alignment ( us, t ) ;

	us = enc_exp ( us, c ) ;

	ts = enc_bitstream ( ts, us ) ;

	ts = enc_rtti_type ( ts, t, lex_typeid ) ;

	ts = enc_destr_func ( ts, d ) ;

	bs = enc_bitstream ( bs, ts ) ;

	unreached_code = 1 ;

	free_exp ( c, 1 ) ;

    } else {

	/* Rethrow the current exception */

	bs = enc_rethrow ( bs ) ;

    }

    return ( bs ) ;

}

/*

    ENCODE A CAUGHT EXPRESSION

    This routine adds the initialiser for an exception handler variable

    of type t to the bitstream bs.  This is obtained by casting the

    current exception value to a pointer to t.

*/

BITSTREAM *enc_thrown

    PROTO_N ( ( bs, t ) )

    PROTO_T ( BITSTREAM *bs X TYPE t )

{

    BITSTREAM *ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

    bs = enc_special ( bs, TOK_from_ptr_void ) ;

    ts = enc_alignment ( ts, t ) ;

    ts = enc_special ( ts, TOK_except_value ) ;

    bs = enc_bitstream ( bs, ts ) ;

    return ( bs ) ;

}

/*

    EXCEPTION SPECIFICATION FLAG

    This flag is set to true if the current function has an exception

    specification.

*/

int in_exception_spec = 0 ;

/*

    ENCODE THE START OF A FUNCTION EXCEPTION HANDLER

    This routine is called at the start of a function definition declared

    with a non-trivial exception specification.  It sets up a try block

    enclosing the complete function body.

*/

BITSTREAM *enc_try_func

    PROTO_N ( ( bs, a ) )

    PROTO_T ( BITSTREAM *bs X EXP a )

{

    if ( !IS_NULL_exp ( a ) ) {

	/* Declare counter variable */

	EXP b = sizeof_init ( a, type_sint ) ;

	ulong n = unit_no ( bs, NULL_id, VAR_tag, 1 ) ;

	ENC_variable ( bs ) ;

	bs = enc_access ( bs, crt_func_access ) ;

	ENC_make_tag ( bs, n ) ;

	bs = enc_exp ( bs, b ) ;

	free_exp ( b, 1 ) ;

	last_params [ DUMMY_count ] = n ;

    }

    no_destructors++ ;

    in_exception_spec++ ;

    ENC_SEQ_SMALL ( bs, 1 ) ;

    bs = enc_try_start ( bs, last_params + DUMMY_catch, ( unsigned ) 1 ) ;

    return ( bs ) ;

}

/*

    BAD EXCEPTION TYPE

    This type represents the standard class 'std::bad_exception' which has

    a special meaning within exception specifications.

*/

static TYPE bad_except = NULL_type ;

/*

    ENCODE THE END OF A FUNCTION EXCEPTION HANDLER

    This routine is called at the end of a function definition declared

    with the set of exceptions p.  It sets up a list of exception handlers

    for each element of p which re-throw the current exception.  If the

    exception remains uncaught then the bad exception token is called

    (which calls unexpected).

*/

BITSTREAM *enc_catch_func

    PROTO_N ( ( bs, p, a ) )

    PROTO_T ( BITSTREAM *bs X LIST ( TYPE ) p X EXP a )

{

    int rethrow = 0 ;

    bs = enc_try_end ( bs, last_params [ DUMMY_catch ] ) ;

    if ( !IS_NULL_exp ( a ) ) {

	ENC_SEQ_SMALL ( bs, 1 ) ;

	bs = enc_exp ( bs, a ) ;

    }

    if ( EQ_list ( p, univ_type_set ) ) {

	/* Can throw any exception */

	rethrow = 1 ;

    } else {

	BITSTREAM *ts ;

	int have_bad = 0 ;

	if ( !IS_NULL_list ( p ) ) {

	    /* Check list of exceptions */

	    unsigned n = 0 ;

	    LIST ( TYPE ) q = p ;

	    while ( !IS_NULL_list ( q ) ) {

		TYPE t = DEREF_type ( HEAD_list ( q ) ) ;

		if ( !IS_NULL_type ( t ) ) n++ ;

		q = TAIL_list ( q ) ;

	    }

	    if ( n ) {

		ulong lab ;

		TYPE s = bad_except ;

		if ( IS_NULL_type ( s ) ) {

		    s = find_std_type ( "bad_exception", 1, 0 ) ;

		    s = exception_type ( s, 0 ) ;

		    bad_except = s ;

		}

		lab = unit_no ( bs, NULL_id, VAR_label, 1 ) ;

		ENC_conditional ( bs ) ;

		ENC_make_label ( bs, lab ) ;

		ENC_SEQUENCE ( bs, n ) ;

		while ( !IS_NULL_list ( p ) ) {

		    TYPE t = DEREF_type ( HEAD_list ( p ) ) ;

		    if ( !IS_NULL_type ( t ) ) {

			t = exception_type ( t, 0 ) ;

			if ( eq_type ( t, s ) ) have_bad = 1 ;

			bs = enc_catch ( bs, t, lab, ( unsigned ) 0 ) ;

		    }

		    p = TAIL_list ( p ) ;

		}

		rethrow = 1 ;

	    }

	}

	bs = enc_special ( bs, TOK_except_bad ) ;

	ts = start_bitstream ( NIL ( FILE ), bs->link ) ;

	ts = enc_make_snat ( ts, have_bad ) ;

	bs = enc_bitstream ( bs, ts ) ;

    }

    if ( rethrow ) {

	/* Re-throw the current exception */

	bs = enc_special ( bs, TOK_except_rethrow ) ;

	unreached_code = 1 ;

    }

    in_exception_spec-- ;

    no_destructors-- ;

    UNUSED ( a ) ;

    return ( bs ) ;

}

#endif /* LANGUAGE_CPP */

#endif /* TDF_OUTPUT */