Error trying to use type from GNU GMP library as yylval type for Bison

Question

I am trying to use a type mpz_tfrom the GMP library as a type for yylvalby including the following in a Bison file:

%define api.value.type {mpz_t}

I checked the generated parser and correctly created the string typedef mpz_t YYSTYPE, while YYSTYPEusing this to create yylval.

mpz_tis typdefed as typedef __mpz_struct mpz_t[1];in the GMP header file gmp.h. In turn, __mpz_structis typdefed as

typedef struct
{
    // struct members here - don't believe they're important
} __mpz_struct;

Bison works without errors, but whenever I try to create an executable, I get the following error:

calc.tab.c: In the function "yyparse:

calc.tab.c: 1148: 12: error: incompatible types when assigning type YYSTYPE from type 'Struct __mpz_struct *

* ++ yyvsp = yylval;

yyvsp YYSTYPE.

, ?

Answer 1

, mpz_t typedef'ed :

typedef __mpz_struct mpz_t[1];

mpz_t :

mpz_t a, b;
mpz_init(b);
a = b;  /* Error: incompatible types when assigning to type ‘mpz_t’ */
        /* from type ‘struct __mpz_struct *’                        */

:

mpz_t a, b;
mpz_inits(a, b, 0);
mpz_set(a, b);   /* a is now a copy of b */

mpz_t - , gmp . . 1 .

Bison , YYSTYPE (. 2), , . , YYSTYPE , . , bison , %union.

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  --top;
  

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1. GMP

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memcpy(a, b, sizeof(a));

b :

mpz_mul(b, b, b);  /* Set b to b squared */

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tmp = realloc(b->_mp_d, 2 * b->_mp_size);
if (tmp) b->_mp_d = tmp;

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