C-Flat Abstract Syntax Tree

struct decl {
    char *name;
    int nlocals;
    struct type *type;
    struct expr *value;
    struct stmt *code;
    struct symbol *symbol;
    struct decl *next;
};

struct stmt {
    int kind;
    struct decl *decl;
    struct expr *expr;
    struct stmt *body;
    struct stmt *ebody;
    struct stmt *next;
};

#define STMT_KIND_DECL    0
#define STMT_KIND_EXPR    1
#define STMT_KIND_IF_ELSE 2
#define STMT_KIND_WHILE   3
#define STMT_KIND_RETURN  4
#define STMT_KIND_BLOCK   5

struct expr {
    int kind;
    struct expr *left;
    struct expr *right;
    const char *name;
    int constant;
    struct symbol *symbol;
    int reg;
};

#define EXPR_KIND_LT       0
#define EXPR_KIND_LE       1
#define EXPR_KIND_EQ       2
#define EXPR_KIND_NE       3
#define EXPR_KIND_GT       4
#define EXPR_KIND_GE       5
#define EXPR_KIND_NOT      6
#define EXPR_KIND_ADD      7
#define EXPR_KIND_SUB      8
#define EXPR_KIND_MUL      9
#define EXPR_KIND_DIV      10
#define EXPR_KIND_NEG      11
#define EXPR_KIND_MOD      12
#define EXPR_KIND_ASSIGN   13
#define EXPR_KIND_CALL     14
#define EXPR_KIND_ARG      15
#define EXPR_KIND_NAME     16
#define EXPR_KIND_INT      17
#define EXPR_KIND_CHAR     18
#define EXPR_KIND_BOOLEAN  19

struct symbol {
    int kind;
    int which;
    struct type *type;
    char *name;
};

#define SYMBOL_KIND_NAME    0
#define SYMBOL_KIND_LOCAL   1
#define SYMBOL_KIND_PARAM   2
#define SYMBOL_KIND_GLOBAL  3

struct type {
    int kind;
    struct param_list *params;
    struct type *rtype;
};

#define TYPE_KIND_CHARACTER 1
#define TYPE_KIND_INTEGER   2
#define TYPE_KIND_STRING    3
#define TYPE_KIND_BOOLEAN   4
#define TYPE_KIND_VOID      5
#define TYPE_KIND_FUNCTION  6

struct param_list {
    char *name;
    struct type *type;
    struct param_list *next;
};

/******* symbol table operations ********/

int scope_enter();
int scope_level();
int scope_exit();

int scope_bind( char *name, struct symbol *symbol );

struct symbol * scope_lookup( const char *name );