1 |
/* printf */ |
/* printf, sscanf, fgets, fprintf */ |
2 |
#include <stdio.h> |
#include <stdio.h> |
3 |
/* EXIT_SUCCESS */ |
/* exit, EXIT_SUCCESS, malloc, free */ |
4 |
#include <stdlib.h> |
#include <stdlib.h> |
5 |
/* NULL */ |
/* NULL */ |
6 |
#include <stddef.h> |
#include <stddef.h> |
7 |
/* dlopen, dlsym, dlerror */ |
/* dlopen, dlsym, dlerror */ |
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#include <dlfcn.h> |
#include <dlfcn.h> |
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/* assert */ |
/* strcmp, strcpy, strlen, strcat, strdup */ |
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#include <assert.h> |
#include <string.h> |
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#define HASHTBLSIZE 65536 |
#define HASHTBLSIZE 65536 |
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typedef struct stack_item |
/* First, define some types. */ |
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{ |
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/* A value of some type */ |
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typedef struct { |
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enum { |
enum { |
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value, /* Integer */ |
integer, |
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string, |
string, |
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ref, /* Reference (to an element in the |
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hash table) */ |
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func, /* Function pointer */ |
func, /* Function pointer */ |
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symbol, |
symb, |
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list |
list |
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} type; /* Type of stack element */ |
} type; /* Type of stack element */ |
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union { |
union { |
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void* ptr; /* Pointer to the content */ |
void *ptr; /* Pointer to the content */ |
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int val; /* ...or an integer */ |
int val; /* ...or an integer */ |
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} content; /* Stores a pointer or an integer */ |
} content; /* Stores a pointer or an integer */ |
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char* id; /* Symbol name */ |
int refcount; /* Reference counter */ |
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struct stack_item* next; /* Next element */ |
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} stackitem; |
} value; |
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/* A symbol with a name and possible value */ |
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/* (These do not need reference counters, they are kept unique by |
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hashing.) */ |
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typedef struct symbol_struct { |
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char *id; /* Symbol name */ |
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value *val; /* The value (if any) bound to it */ |
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struct symbol_struct *next; /* In case of hashing conflicts, a */ |
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} symbol; /* symbol is a kind of stack item. */ |
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typedef stackitem* hashtbl[HASHTBLSIZE]; /* Hash table declaration */ |
/* A type for a hash table for symbols */ |
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typedef void (*funcp)(stackitem**); /* funcp is a pointer to a |
typedef symbol *hashtbl[HASHTBLSIZE]; /* Hash table declaration */ |
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void function (stackitem **) */ |
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/* Initialize a newly created hash table. */ |
/* An item (value) on a stack */ |
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void init_hashtbl(hashtbl out_hash) |
typedef struct stackitem_struct |
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{ |
{ |
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long i; |
value *item; /* The value on the stack */ |
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struct stackitem_struct *next; /* Next item */ |
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} stackitem; |
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/* An environment; gives access to the stack and a hash table of |
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defined symbols */ |
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typedef struct { |
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stackitem *head; /* Head of the stack */ |
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hashtbl symbols; /* Hash table of all variable bindings */ |
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int err; /* Error flag */ |
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int non_eval_flag; |
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} environment; |
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/* A type for pointers to external functions */ |
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typedef void (*funcp)(environment *); /* funcp is a pointer to a void |
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function (environment *) */ |
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/* Initialize a newly created environment */ |
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void init_env(environment *env) |
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{ |
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int i; |
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env->err= 0; |
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env->non_eval_flag= 0; |
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for(i= 0; i<HASHTBLSIZE; i++) |
for(i= 0; i<HASHTBLSIZE; i++) |
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out_hash[i]= NULL; |
env->symbols[i]= NULL; |
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} |
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void printerr(const char* in_string) { |
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fprintf(stderr, "Err: %s\n", in_string); |
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} |
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/* Throw away a value */ |
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void free_val(value *val){ |
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stackitem *item, *temp; |
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val->refcount--; /* Decrease the reference count */ |
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if(val->refcount == 0){ |
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switch (val->type){ /* and free the contents if necessary */ |
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case string: |
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free(val->content.ptr); |
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break; |
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case list: /* lists needs to be freed recursively */ |
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item=val->content.ptr; |
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while(item != NULL) { /* for all stack items */ |
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free_val(item->item); /* free the value */ |
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temp=item->next; /* save next ptr */ |
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free(item); /* free the stackitem */ |
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item=temp; /* go to next stackitem */ |
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} |
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free(val); /* Free the actual list value */ |
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break; |
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default: |
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break; |
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} |
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} |
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} |
} |
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/* Returns a pointer to an element in the hash table. */ |
/* Discard the top element of the stack. */ |
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stackitem** hash(hashtbl in_hashtbl, const char* in_string) |
extern void toss(environment *env) |
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{ |
{ |
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long i= 0; |
stackitem *temp= env->head; |
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unsigned long out_hash= 0; |
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if((env->head)==NULL) { |
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printerr("Too Few Arguments"); |
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env->err=1; |
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return; |
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} |
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free_val(env->head->item); /* Free the value */ |
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env->head= env->head->next; /* Remove the top stack item */ |
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free(temp); /* Free the old top stack item */ |
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} |
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/* Returns a pointer to a pointer to an element in the hash table. */ |
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symbol **hash(hashtbl in_hashtbl, const char *in_string) |
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{ |
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int i= 0; |
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unsigned int out_hash= 0; |
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char key= '\0'; |
char key= '\0'; |
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stackitem** position; |
symbol **position; |
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while(1){ /* Hash in_string */ |
while(1){ /* Hash in_string */ |
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key= in_string[i++]; |
key= in_string[i++]; |
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} |
} |
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/* Generic push function. */ |
/* Generic push function. */ |
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int push(stackitem** stack_head, stackitem* in_item) |
void push(stackitem** stack_head, stackitem* in_item) |
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{ |
{ |
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in_item->next= *stack_head; |
in_item->next= *stack_head; |
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*stack_head= in_item; |
*stack_head= in_item; |
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return 1; |
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} |
} |
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/* Push a value on the stack. */ |
/* Push a value onto the stack */ |
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int push_val(stackitem** stack_head, int in_val) |
void push_val(stackitem **stack_head, value *val) |
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{ |
{ |
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stackitem* new_item= malloc(sizeof(stackitem)); |
stackitem *new_item= malloc(sizeof(stackitem)); |
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assert(new_item != NULL); |
new_item->item= val; |
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new_item->content.val= in_val; |
val->refcount++; |
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new_item->type= value; |
push(stack_head, new_item); |
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} |
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/* Push an integer onto the stack. */ |
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void push_int(stackitem **stack_head, int in_val) |
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{ |
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value *new_value= malloc(sizeof(value)); |
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stackitem *new_item= malloc(sizeof(stackitem)); |
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new_item->item= new_value; |
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new_value->content.val= in_val; |
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new_value->type= integer; |
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new_value->refcount=1; |
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push(stack_head, new_item); |
push(stack_head, new_item); |
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return 1; |
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} |
} |
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/* Copy a string onto the stack. */ |
/* Copy a string onto the stack. */ |
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int push_cstring(stackitem** stack_head, const char* in_string) |
void push_cstring(stackitem **stack_head, const char *in_string) |
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{ |
{ |
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stackitem* new_item= malloc(sizeof(stackitem)); |
value *new_value= malloc(sizeof(value)); |
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new_item->content.ptr= malloc(strlen(in_string)+1); |
stackitem *new_item= malloc(sizeof(stackitem)); |
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strcpy(new_item->content.ptr, in_string); |
new_item->item=new_value; |
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new_item->type= string; |
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new_value->content.ptr= malloc(strlen(in_string)+1); |
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strcpy(new_value->content.ptr, in_string); |
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new_value->type= string; |
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new_value->refcount=1; |
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push(stack_head, new_item); |
push(stack_head, new_item); |
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return 1; |
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} |
} |
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/* Create a new hash entry. */ |
/* Mangle a symbol name to a valid C identifier name */ |
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int mk_hashentry(hashtbl in_hashtbl, stackitem* in_item, const char* id) |
char *mangle_str(const char *old_string){ |
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{ |
char validchars[] |
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in_item->id= malloc(strlen(id)+1); |
="0123456789abcdef"; |
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char *new_string, *current; |
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strcpy(in_item->id, id); |
new_string=malloc((strlen(old_string)*2)+4); |
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push(hash(in_hashtbl, id), in_item); |
strcpy(new_string, "sx_"); /* Stack eXternal */ |
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current=new_string+3; |
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while(old_string[0] != '\0'){ |
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current[0]=validchars[old_string[0]/16]; |
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current[1]=validchars[old_string[0]%16]; |
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current+=2; |
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old_string++; |
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} |
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current[0]='\0'; |
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return 1; |
return new_string; /* The caller must free() it */ |
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} |
} |
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/* Define a new function in the hash table. */ |
extern void mangle(environment *env){ |
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void def_func(hashtbl in_hashtbl, funcp in_func, const char* id) |
value *new_value; |
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{ |
char *new_string; |
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stackitem* temp= malloc(sizeof(stackitem)); |
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temp->type= func; |
if((env->head)==NULL) { |
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temp->content.ptr= in_func; |
printerr("Too Few Arguments"); |
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env->err=1; |
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return; |
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} |
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mk_hashentry(in_hashtbl, temp, id); |
if(env->head->item->type!=string) { |
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} |
printerr("Bad Argument Type"); |
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env->err=2; |
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return; |
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} |
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/* Define a new symbol in the hash table. */ |
new_string= mangle_str((const char *)(env->head->item->content.ptr)); |
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void def_sym(hashtbl in_hashtbl, const char* id) |
|
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{ |
toss(env); |
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stackitem* temp= malloc(sizeof(stackitem)); |
if(env->err) return; |
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temp->type= symbol; |
new_value= malloc(sizeof(value)); |
240 |
mk_hashentry(in_hashtbl, temp, id); |
new_value->content.ptr= new_string; |
241 |
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new_value->type= string; |
242 |
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new_value->refcount=1; |
243 |
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244 |
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push_val(&(env->head), new_value); |
245 |
} |
} |
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/* Push a reference to an entry in the hash table onto the stack. */ |
/* Push a symbol onto the stack. */ |
248 |
int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string) |
void push_sym(environment *env, const char *in_string) |
249 |
{ |
{ |
250 |
static void* handle= NULL; |
stackitem *new_item; /* The new stack item */ |
251 |
void* symbol; |
/* ...which will contain... */ |
252 |
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value *new_value; /* A new symbol value */ |
253 |
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/* ...which might point to... */ |
254 |
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symbol **new_symbol; /* (if needed) A new actual symbol */ |
255 |
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/* ...which, if possible, will be bound to... */ |
256 |
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value *new_fvalue; /* (if needed) A new function value */ |
257 |
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/* ...which will point to... */ |
258 |
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void *funcptr; /* A function pointer */ |
259 |
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260 |
stackitem* new_item= malloc(sizeof(stackitem)); |
static void *handle= NULL; /* Dynamic linker handle */ |
261 |
new_item->content.ptr= *hash(in_hash, in_string); |
const char *dlerr; /* Dynamic linker error */ |
262 |
new_item->type= ref; |
char *mangled; /* Mangled function name */ |
263 |
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264 |
if(new_item->content.ptr==NULL) { /* If hash entry empty */ |
/* Create a new stack item containing a new value */ |
265 |
if(handle==NULL) /* If no handle */ |
new_item= malloc(sizeof(stackitem)); |
266 |
handle= dlopen(NULL, RTLD_LAZY); |
new_value= malloc(sizeof(value)); |
267 |
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new_item->item=new_value; |
268 |
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269 |
symbol= dlsym(handle, in_string); /* Get function pointer */ |
/* The new value is a symbol */ |
270 |
if(dlerror()==NULL) /* If existing function pointer */ |
new_value->type= symb; |
271 |
def_func(in_hash, symbol, in_string); /* Store function pointer */ |
new_value->refcount= 1; |
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else |
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def_sym(in_hash, in_string); /* Make symbol */ |
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new_item->content.ptr= *hash(in_hash, in_string); /* The new reference |
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shouldn't point at |
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NULL */ |
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new_item->type= ref; |
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} |
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272 |
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273 |
push(stack_head, new_item); |
/* Look up the symbol name in the hash table */ |
274 |
return 1; |
new_symbol= hash(env->symbols, in_string); |
275 |
} |
new_value->content.ptr= *new_symbol; |
276 |
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277 |
void printerr(const char* in_string) { |
if(*new_symbol==NULL) { /* If symbol was undefined */ |
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fprintf(stderr, "Err: %s\n", in_string); |
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} |
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278 |
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279 |
/* Discard the top element of the stack. */ |
/* Create a new symbol */ |
280 |
extern void toss(stackitem** stack_head) |
(*new_symbol)= malloc(sizeof(symbol)); |
281 |
{ |
(*new_symbol)->val= NULL; /* undefined value */ |
282 |
stackitem* temp= *stack_head; |
(*new_symbol)->next= NULL; |
283 |
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(*new_symbol)->id= malloc(strlen(in_string)+1); |
284 |
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strcpy((*new_symbol)->id, in_string); |
285 |
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|
286 |
if((*stack_head)==NULL) { |
/* Intern the new symbol in the hash table */ |
287 |
printerr("Stack empty"); |
new_value->content.ptr= *new_symbol; |
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return; |
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} |
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if((*stack_head)->type==string) |
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free((*stack_head)->content.ptr); |
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288 |
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289 |
*stack_head= (*stack_head)->next; |
/* Try to load the symbol name as an external function, to see if |
290 |
free(temp); |
we should bind the symbol to a new function pointer value */ |
291 |
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if(handle==NULL) /* If no handle */ |
292 |
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handle= dlopen(NULL, RTLD_LAZY); |
293 |
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294 |
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funcptr= dlsym(handle, in_string); /* Get function pointer */ |
295 |
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dlerr=dlerror(); |
296 |
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if(dlerr != NULL) { /* If no function was found */ |
297 |
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mangled=mangle_str(in_string); |
298 |
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funcptr= dlsym(handle, mangled); /* try mangling it */ |
299 |
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free(mangled); |
300 |
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dlerr=dlerror(); |
301 |
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} |
302 |
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if(dlerr==NULL) { /* If a function was found */ |
303 |
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new_fvalue= malloc(sizeof(value)); /* Create a new value */ |
304 |
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new_fvalue->type=func; /* The new value is a function pointer */ |
305 |
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new_fvalue->content.ptr=funcptr; /* Store function pointer */ |
306 |
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(*new_symbol)->val= new_fvalue; /* Bind the symbol to the new |
307 |
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function value */ |
308 |
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new_fvalue->refcount= 1; |
309 |
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} |
310 |
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} |
311 |
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push(&(env->head), new_item); |
312 |
} |
} |
313 |
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314 |
/* Print newline. */ |
/* Print newline. */ |
317 |
printf("\n"); |
printf("\n"); |
318 |
} |
} |
319 |
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320 |
/* Prints the top element of the stack. */ |
/* Gets the type of a value */ |
321 |
extern void print_(stackitem** stack_head) |
extern void type(environment *env){ |
322 |
{ |
int typenum; |
323 |
stackitem* temp= *stack_head; |
|
324 |
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if((env->head)==NULL) { |
325 |
if(temp==NULL) { |
printerr("Too Few Arguments"); |
326 |
printerr("Stack empty"); |
env->err=1; |
327 |
return; |
return; |
328 |
} |
} |
329 |
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typenum=env->head->item->type; |
330 |
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toss(env); |
331 |
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switch(typenum){ |
332 |
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case integer: |
333 |
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push_sym(env, "integer"); |
334 |
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break; |
335 |
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case string: |
336 |
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push_sym(env, "string"); |
337 |
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break; |
338 |
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case symb: |
339 |
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push_sym(env, "symbol"); |
340 |
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break; |
341 |
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case func: |
342 |
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push_sym(env, "function"); |
343 |
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break; |
344 |
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case list: |
345 |
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push_sym(env, "list"); |
346 |
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break; |
347 |
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default: |
348 |
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push_sym(env, "unknown"); |
349 |
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break; |
350 |
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} |
351 |
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} |
352 |
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|
353 |
while(temp->type==ref) |
/* Prints the top element of the stack. */ |
354 |
temp= temp->content.ptr; |
void print_h(stackitem *stack_head) |
355 |
|
{ |
356 |
switch(temp->type) { |
switch(stack_head->item->type) { |
357 |
case value: |
case integer: |
358 |
printf("%d", temp->content.val); |
printf("%d", stack_head->item->content.val); |
359 |
break; |
break; |
360 |
case string: |
case string: |
361 |
printf("\"%s\"", (char*)temp->content.ptr); |
printf("\"%s\"", (char*)stack_head->item->content.ptr); |
362 |
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break; |
363 |
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case symb: |
364 |
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printf("%s", ((symbol *)(stack_head->item->content.ptr))->id); |
365 |
break; |
break; |
|
case symbol: |
|
366 |
case func: |
case func: |
367 |
printf("%s", temp->id); |
printf("#<function %p>", (funcp)(stack_head->item->content.ptr)); |
368 |
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break; |
369 |
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case list: |
370 |
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/* A list is just a stack, so make stack_head point to it */ |
371 |
|
stack_head=(stackitem *)(stack_head->item->content.ptr); |
372 |
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printf("[ "); |
373 |
|
while(stack_head != NULL) { |
374 |
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print_h(stack_head); |
375 |
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printf(" "); |
376 |
|
stack_head=stack_head->next; |
377 |
|
} |
378 |
|
printf("]"); |
379 |
break; |
break; |
380 |
default: |
default: |
381 |
printf("%p", temp->content.ptr); |
printf("#<unknown %p>", (stack_head->item->content.ptr)); |
382 |
break; |
break; |
383 |
} |
} |
384 |
} |
} |
385 |
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|
386 |
|
extern void print_(environment *env) { |
387 |
|
if(env->head==NULL) { |
388 |
|
printerr("Too Few Arguments"); |
389 |
|
env->err=1; |
390 |
|
return; |
391 |
|
} |
392 |
|
print_h(env->head); |
393 |
|
} |
394 |
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|
395 |
/* Prints the top element of the stack and then discards it. */ |
/* Prints the top element of the stack and then discards it. */ |
396 |
extern void print(stackitem** stack_head) |
extern void print(environment *env) |
397 |
{ |
{ |
398 |
print_(stack_head); |
print_(env); |
399 |
toss(stack_head); |
if(env->err) return; |
400 |
|
toss(env); |
401 |
} |
} |
402 |
|
|
403 |
/* Only to be called by function printstack. */ |
/* Only to be called by function printstack. */ |
404 |
void print_st(stackitem* stack_head, long counter) |
void print_st(stackitem *stack_head, long counter) |
405 |
{ |
{ |
406 |
if(stack_head->next != NULL) |
if(stack_head->next != NULL) |
407 |
print_st(stack_head->next, counter+1); |
print_st(stack_head->next, counter+1); |
|
|
|
408 |
printf("%ld: ", counter); |
printf("%ld: ", counter); |
409 |
print_(&stack_head); |
print_h(stack_head); |
410 |
nl(); |
nl(); |
411 |
} |
} |
412 |
|
|
413 |
/* Prints the stack. */ |
/* Prints the stack. */ |
414 |
extern void printstack(stackitem** stack_head) |
extern void printstack(environment *env) |
415 |
{ |
{ |
416 |
if(*stack_head != NULL) { |
if(env->head == NULL) { |
417 |
print_st(*stack_head, 1); |
return; |
|
nl(); |
|
|
} else { |
|
|
printerr("Stack empty"); |
|
418 |
} |
} |
419 |
|
print_st(env->head, 1); |
420 |
|
nl(); |
421 |
} |
} |
422 |
|
|
423 |
/* If the top element is a reference, determine if it's a reference to a |
/* Swap the two top elements on the stack. */ |
424 |
function, and if it is, toss the reference and execute the function. */ |
extern void swap(environment *env) |
|
extern void eval(stackitem** stack_head) |
|
425 |
{ |
{ |
426 |
funcp in_func; |
stackitem *temp= env->head; |
427 |
stackitem* temp= *stack_head; |
|
428 |
|
if(env->head==NULL || env->head->next==NULL) { |
429 |
|
printerr("Too Few Arguments"); |
430 |
|
env->err=1; |
431 |
|
return; |
432 |
|
} |
433 |
|
|
434 |
|
env->head= env->head->next; |
435 |
|
temp->next= env->head->next; |
436 |
|
env->head->next= temp; |
437 |
|
} |
438 |
|
|
439 |
if(temp==NULL) { |
/* Recall a value from a symbol, if bound */ |
440 |
printerr("Stack empty"); |
extern void rcl(environment *env) |
441 |
|
{ |
442 |
|
value *val; |
443 |
|
|
444 |
|
if(env->head == NULL) { |
445 |
|
printerr("Too Few Arguments"); |
446 |
|
env->err=1; |
447 |
return; |
return; |
448 |
} |
} |
449 |
|
|
450 |
while(temp->type==ref) |
if(env->head->item->type!=symb) { |
451 |
temp= temp->content.ptr; |
printerr("Bad Argument Type"); |
452 |
|
env->err=2; |
453 |
|
return; |
454 |
|
} |
455 |
|
|
456 |
if(temp->type==func) { |
val=((symbol *)(env->head->item->content.ptr))->val; |
457 |
in_func= (funcp)(temp->content.ptr); |
if(val == NULL){ |
458 |
toss(stack_head); |
printerr("Unbound Variable"); |
459 |
(*in_func)(stack_head); |
env->err=3; |
460 |
return; |
return; |
461 |
} |
} |
462 |
|
toss(env); /* toss the symbol */ |
463 |
printerr("Couldn't evaluate"); |
if(env->err) return; |
464 |
|
push_val(&(env->head), val); /* Return its bound value */ |
465 |
|
} |
466 |
|
|
467 |
|
void stack_read(environment*, char*); |
468 |
|
|
469 |
|
/* If the top element is a symbol, determine if it's bound to a |
470 |
|
function value, and if it is, toss the symbol and execute the |
471 |
|
function. */ |
472 |
|
extern void eval(environment *env) |
473 |
|
{ |
474 |
|
funcp in_func; |
475 |
|
value* temp_val; |
476 |
|
stackitem* iterator; |
477 |
|
char* temp_string; |
478 |
|
|
479 |
|
if(env->head==NULL) { |
480 |
|
printerr("Too Few Arguments"); |
481 |
|
env->err=1; |
482 |
|
return; |
483 |
|
} |
484 |
|
|
485 |
|
switch(env->head->item->type) { |
486 |
|
/* if it's a symbol */ |
487 |
|
case symb: |
488 |
|
rcl(env); /* get its contents */ |
489 |
|
if(env->err) return; |
490 |
|
if(env->head->item->type!=symb){ /* don't recurse symbols */ |
491 |
|
eval(env); /* evaluate the value */ |
492 |
|
return; |
493 |
|
} |
494 |
|
break; |
495 |
|
|
496 |
|
/* If it's a lone function value, run it */ |
497 |
|
case func: |
498 |
|
in_func= (funcp)(env->head->item->content.ptr); |
499 |
|
toss(env); |
500 |
|
if(env->err) return; |
501 |
|
(*in_func)(env); |
502 |
|
break; |
503 |
|
|
504 |
|
/* If it's a list */ |
505 |
|
case list: |
506 |
|
temp_val= env->head->item; |
507 |
|
env->head->item->refcount++; |
508 |
|
toss(env); |
509 |
|
if(env->err) return; |
510 |
|
iterator= (stackitem*)temp_val->content.ptr; |
511 |
|
while(iterator!=NULL && iterator->item!=NULL) { |
512 |
|
push_val(&(env->head), iterator->item); |
513 |
|
if(env->head->item->type==symb |
514 |
|
&& strcmp(";", ((symbol*)(env->head->item->content.ptr))->id)==0) { |
515 |
|
toss(env); |
516 |
|
if(env->err) return; |
517 |
|
eval(env); |
518 |
|
if(env->err) return; |
519 |
|
} |
520 |
|
iterator= iterator->next; |
521 |
|
} |
522 |
|
free_val(temp_val); |
523 |
|
break; |
524 |
|
|
525 |
|
/* If it's a string */ |
526 |
|
case string: |
527 |
|
temp_val= env->head->item; |
528 |
|
env->head->item->refcount++; |
529 |
|
toss(env); |
530 |
|
if(env->err) return; |
531 |
|
temp_string= malloc(strlen((char*)temp_val->content.ptr)+5); |
532 |
|
strcpy(temp_string, "[ "); |
533 |
|
strcat(temp_string, (char*)temp_val->content.ptr); |
534 |
|
strcat(temp_string, " ]"); |
535 |
|
stack_read(env, temp_string); |
536 |
|
eval(env); |
537 |
|
if(env->err) return; |
538 |
|
free_val(temp_val); |
539 |
|
free(temp_string); |
540 |
|
break; |
541 |
|
|
542 |
|
default: |
543 |
|
} |
544 |
|
} |
545 |
|
|
546 |
|
/* Reverse (flip) a list */ |
547 |
|
extern void rev(environment *env){ |
548 |
|
stackitem *old_head, *new_head, *item; |
549 |
|
|
550 |
|
if((env->head)==NULL) { |
551 |
|
printerr("Too Few Arguments"); |
552 |
|
env->err=1; |
553 |
|
return; |
554 |
|
} |
555 |
|
|
556 |
|
if(env->head->item->type!=list) { |
557 |
|
printerr("Bad Argument Type"); |
558 |
|
env->err=2; |
559 |
|
return; |
560 |
|
} |
561 |
|
|
562 |
|
old_head=(stackitem *)(env->head->item->content.ptr); |
563 |
|
new_head=NULL; |
564 |
|
while(old_head != NULL){ |
565 |
|
item=old_head; |
566 |
|
old_head=old_head->next; |
567 |
|
item->next=new_head; |
568 |
|
new_head=item; |
569 |
|
} |
570 |
|
env->head->item->content.ptr=new_head; |
571 |
} |
} |
572 |
|
|
573 |
/* Make a list. */ |
/* Make a list. */ |
574 |
extern void pack(stackitem** stack_head) |
extern void pack(environment *env) |
575 |
{ |
{ |
576 |
void* delimiter; |
void* delimiter; |
577 |
stackitem *iterator, *temp, *pack; |
stackitem *iterator, *temp; |
578 |
|
value *pack; |
579 |
|
|
580 |
delimiter= (*stack_head)->content.ptr; /* Get delimiter */ |
delimiter= env->head->item->content.ptr; /* Get delimiter */ |
581 |
toss(stack_head); |
toss(env); |
582 |
|
|
583 |
iterator= *stack_head; |
iterator= env->head; |
584 |
|
|
585 |
if(iterator==NULL || iterator->content.ptr==delimiter) { |
if(iterator==NULL || iterator->item->content.ptr==delimiter) { |
586 |
temp= NULL; |
temp= NULL; |
587 |
toss(stack_head); |
toss(env); |
588 |
} else { |
} else { |
589 |
/* Search for first delimiter */ |
/* Search for first delimiter */ |
590 |
while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter) |
while(iterator->next!=NULL |
591 |
|
&& iterator->next->item->content.ptr!=delimiter) |
592 |
iterator= iterator->next; |
iterator= iterator->next; |
593 |
|
|
594 |
/* Extract list */ |
/* Extract list */ |
595 |
temp= *stack_head; |
temp= env->head; |
596 |
*stack_head= iterator->next; |
env->head= iterator->next; |
597 |
iterator->next= NULL; |
iterator->next= NULL; |
598 |
|
|
599 |
if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter) |
if(env->head!=NULL) |
600 |
toss(stack_head); |
toss(env); |
601 |
} |
} |
602 |
|
|
603 |
/* Push list */ |
/* Push list */ |
604 |
pack= malloc(sizeof(stackitem)); |
pack= malloc(sizeof(value)); |
605 |
pack->type= list; |
pack->type= list; |
606 |
pack->content.ptr= temp; |
pack->content.ptr= temp; |
607 |
|
pack->refcount= 1; |
608 |
|
|
609 |
|
temp= malloc(sizeof(stackitem)); |
610 |
|
temp->item= pack; |
611 |
|
|
612 |
push(stack_head, pack); |
push(&(env->head), temp); |
613 |
|
rev(env); |
614 |
} |
} |
615 |
|
|
616 |
/* Parse input. */ |
/* Parse input. */ |
617 |
int stack_read(stackitem** stack_head, hashtbl in_hash, char* in_line) |
void stack_read(environment *env, char *in_line) |
618 |
{ |
{ |
619 |
char *temp, *rest; |
char *temp, *rest; |
620 |
int itemp; |
int itemp; |
621 |
size_t inlength= strlen(in_line)+1; |
size_t inlength= strlen(in_line)+1; |
622 |
int convert= 0; |
int convert= 0; |
|
static int non_eval_flag= 0; |
|
623 |
|
|
624 |
temp= malloc(inlength); |
temp= malloc(inlength); |
625 |
rest= malloc(inlength); |
rest= malloc(inlength); |
626 |
|
|
627 |
do { |
do { |
628 |
|
/* If comment */ |
629 |
|
if((convert= sscanf(in_line, "#%[^\n\r]", rest))) { |
630 |
|
free(temp); free(rest); |
631 |
|
return; |
632 |
|
} |
633 |
|
|
634 |
/* If string */ |
/* If string */ |
635 |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
636 |
push_cstring(stack_head, temp); |
push_cstring(&(env->head), temp); |
637 |
break; |
break; |
638 |
} |
} |
639 |
/* If value */ |
/* If integer */ |
640 |
if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest))) { |
if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest))) { |
641 |
push_val(stack_head, itemp); |
push_int(&(env->head), itemp); |
642 |
break; |
break; |
643 |
} |
} |
644 |
/* Escape ';' with '\' */ |
/* Escape ';' with '\' */ |
645 |
if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest))) { |
if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest))) { |
646 |
temp[1]= '\0'; |
temp[1]= '\0'; |
647 |
push_ref(stack_head, in_hash, temp); |
push_sym(env, temp); |
648 |
break; |
break; |
649 |
} |
} |
650 |
/* If symbol */ |
/* If symbol */ |
651 |
if((convert= sscanf(in_line, "%[^][ ;\n\r]%[^\n\r]", temp, rest))) { |
if((convert= sscanf(in_line, "%[^][ ;\n\r]%[^\n\r]", temp, rest))) { |
652 |
push_ref(stack_head, in_hash, temp); |
push_sym(env, temp); |
653 |
break; |
break; |
654 |
} |
} |
655 |
/* If single char */ |
/* If single char */ |
656 |
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
657 |
if(*temp==';') { |
if(*temp==';') { |
658 |
if(!non_eval_flag) { |
if(!env->non_eval_flag) { |
659 |
eval(stack_head); /* Evaluate top element */ |
eval(env); /* Evaluate top element */ |
660 |
break; |
break; |
661 |
} |
} |
662 |
|
|
663 |
push_ref(stack_head, in_hash, ";"); |
push_sym(env, ";"); |
664 |
break; |
break; |
665 |
} |
} |
666 |
|
|
667 |
if(*temp==']') { |
if(*temp==']') { |
668 |
push_ref(stack_head, in_hash, "["); |
push_sym(env, "["); |
669 |
pack(stack_head); |
pack(env); |
670 |
if(non_eval_flag!=0) |
if(env->non_eval_flag) |
671 |
non_eval_flag--; |
env->non_eval_flag--; |
672 |
break; |
break; |
673 |
} |
} |
674 |
|
|
675 |
if(*temp=='[') { |
if(*temp=='[') { |
676 |
push_ref(stack_head, in_hash, "["); |
push_sym(env, "["); |
677 |
non_eval_flag++; |
env->non_eval_flag++; |
678 |
break; |
break; |
679 |
} |
} |
680 |
} |
} |
681 |
} while(0); |
} while(0); |
682 |
|
|
|
|
|
683 |
free(temp); |
free(temp); |
684 |
|
|
685 |
if(convert<2) { |
if(convert<2) { |
686 |
free(rest); |
free(rest); |
687 |
return 0; |
return; |
688 |
} |
} |
689 |
|
|
690 |
stack_read(stack_head, in_hash, rest); |
stack_read(env, rest); |
691 |
|
|
692 |
free(rest); |
free(rest); |
|
return 1; |
|
693 |
} |
} |
694 |
|
|
695 |
/* Relocate elements of the list on the stack. */ |
/* Relocate elements of the list on the stack. */ |
696 |
extern void expand(stackitem** stack_head) |
extern void expand(environment *env) |
697 |
{ |
{ |
698 |
stackitem *temp, *new_head; |
stackitem *temp, *new_head; |
699 |
|
|
700 |
/* Is top element a list? */ |
/* Is top element a list? */ |
701 |
if((*stack_head)==NULL || (*stack_head)->type!=list) { |
if(env->head==NULL) { |
702 |
printerr("Stack empty or not a list"); |
printerr("Too Few Arguments"); |
703 |
|
env->err=1; |
704 |
|
return; |
705 |
|
} |
706 |
|
if(env->head->item->type!=list) { |
707 |
|
printerr("Bad Argument Type"); |
708 |
|
env->err=2; |
709 |
return; |
return; |
710 |
} |
} |
711 |
|
|
712 |
/* The first list element is the new stack head */ |
rev(env); |
|
new_head= temp= (*stack_head)->content.ptr; |
|
|
toss(stack_head); |
|
713 |
|
|
714 |
if(temp==NULL) |
if(env->err) |
715 |
return; |
return; |
716 |
|
|
717 |
/* Search the end of the list */ |
/* The first list element is the new stack head */ |
718 |
while(temp->next!=NULL) |
new_head= temp= env->head->item->content.ptr; |
|
temp= temp->next; |
|
719 |
|
|
720 |
/* Connect the the tail of the list with the old stack head */ |
env->head->item->refcount++; |
721 |
temp->next= *stack_head; |
toss(env); |
|
*stack_head= new_head; /* ...and voila! */ |
|
|
} |
|
722 |
|
|
723 |
/* Swap the two top elements on the stack. */ |
/* Find the end of the list */ |
724 |
extern void swap(stackitem** stack_head) |
while(temp->next!=NULL) |
725 |
{ |
temp= temp->next; |
|
stackitem* temp= (*stack_head); |
|
|
|
|
|
if((*stack_head)==NULL) { |
|
|
printerr("Stack empty"); |
|
|
return; |
|
|
} |
|
726 |
|
|
727 |
if((*stack_head)->next==NULL) |
/* Connect the tail of the list with the old stack head */ |
728 |
return; |
temp->next= env->head; |
729 |
|
env->head= new_head; /* ...and voila! */ |
730 |
|
|
731 |
*stack_head= (*stack_head)->next; |
} |
|
temp->next= (*stack_head)->next; |
|
|
(*stack_head)->next= temp; |
|
|
} |
|
732 |
|
|
733 |
/* Compares two elements by reference. */ |
/* Compares two elements by reference. */ |
734 |
extern void eq(stackitem** stack_head) |
extern void eq(environment *env) |
735 |
{ |
{ |
736 |
void *left, *right; |
void *left, *right; |
737 |
int result; |
int result; |
738 |
|
|
739 |
if((*stack_head)==NULL || (*stack_head)->next==NULL) { |
if((env->head)==NULL || env->head->next==NULL) { |
740 |
printerr("Not enough elements to compare"); |
printerr("Too Few Arguments"); |
741 |
|
env->err=1; |
742 |
return; |
return; |
743 |
} |
} |
744 |
|
|
745 |
left= (*stack_head)->content.ptr; |
left= env->head->item->content.ptr; |
746 |
swap(stack_head); |
swap(env); |
747 |
right= (*stack_head)->content.ptr; |
right= env->head->item->content.ptr; |
748 |
result= (left==right); |
result= (left==right); |
749 |
|
|
750 |
toss(stack_head); toss(stack_head); |
toss(env); toss(env); |
751 |
push_val(stack_head, (left==right)); |
push_int(&(env->head), result); |
752 |
} |
} |
753 |
|
|
754 |
/* Negates the top element on the stack. */ |
/* Negates the top element on the stack. */ |
755 |
extern void not(stackitem** stack_head) |
extern void not(environment *env) |
756 |
{ |
{ |
757 |
int value; |
int val; |
758 |
|
|
759 |
|
if((env->head)==NULL) { |
760 |
|
printerr("Too Few Arguments"); |
761 |
|
env->err=1; |
762 |
|
return; |
763 |
|
} |
764 |
|
|
765 |
if((*stack_head)==NULL || (*stack_head)->type!=value) { |
if(env->head->item->type!=integer) { |
766 |
printerr("Stack empty or element is not a value"); |
printerr("Bad Argument Type"); |
767 |
|
env->err=2; |
768 |
return; |
return; |
769 |
} |
} |
770 |
|
|
771 |
value= (*stack_head)->content.val; |
val= env->head->item->content.val; |
772 |
toss(stack_head); |
toss(env); |
773 |
push_val(stack_head, !value); |
push_int(&(env->head), !val); |
774 |
} |
} |
775 |
|
|
776 |
/* Compares the two top elements on the stack and return 0 if they're the |
/* Compares the two top elements on the stack and return 0 if they're the |
777 |
same. */ |
same. */ |
778 |
extern void neq(stackitem** stack_head) |
extern void neq(environment *env) |
779 |
{ |
{ |
780 |
eq(stack_head); |
eq(env); |
781 |
not(stack_head); |
not(env); |
782 |
} |
} |
783 |
|
|
784 |
/* Give a symbol some content. */ |
/* Give a symbol some content. */ |
785 |
extern void def(stackitem** stack_head) |
extern void def(environment *env) |
786 |
{ |
{ |
787 |
stackitem *temp, *value; |
symbol *sym; |
788 |
|
|
789 |
if(*stack_head==NULL || (*stack_head)->next==NULL |
/* Needs two values on the stack, the top one must be a symbol */ |
790 |
|| (*stack_head)->type!=ref) { |
if(env->head==NULL || env->head->next==NULL) { |
791 |
printerr("Define what?"); |
printerr("Too Few Arguments"); |
792 |
|
env->err=1; |
793 |
return; |
return; |
794 |
} |
} |
795 |
|
|
796 |
temp= (*stack_head)->content.ptr; |
if(env->head->item->type!=symb) { |
797 |
value= (*stack_head)->next; |
printerr("Bad Argument Type"); |
798 |
temp->content= value->content; |
env->err=2; |
799 |
value->content.ptr=NULL; |
return; |
800 |
temp->type= value->type; |
} |
801 |
|
|
802 |
|
/* long names are a pain */ |
803 |
|
sym=env->head->item->content.ptr; |
804 |
|
|
805 |
|
/* if the symbol was bound to something else, throw it away */ |
806 |
|
if(sym->val != NULL) |
807 |
|
free_val(sym->val); |
808 |
|
|
809 |
toss(stack_head); toss(stack_head); |
/* Bind the symbol to the value */ |
810 |
|
sym->val= env->head->next->item; |
811 |
|
sym->val->refcount++; /* Increase the reference counter */ |
812 |
|
|
813 |
|
toss(env); toss(env); |
814 |
} |
} |
815 |
|
|
816 |
/* Quit stack. */ |
/* Quit stack. */ |
817 |
extern void quit() |
extern void quit(environment *env) |
818 |
{ |
{ |
819 |
exit(EXIT_SUCCESS); |
exit(EXIT_SUCCESS); |
820 |
} |
} |
821 |
|
|
822 |
/* Clear stack */ |
/* Clear stack */ |
823 |
extern void clear(stackitem** stack_head) |
extern void clear(environment *env) |
824 |
|
{ |
825 |
|
while(env->head!=NULL) |
826 |
|
toss(env); |
827 |
|
} |
828 |
|
|
829 |
|
/* List all defined words */ |
830 |
|
extern void words(environment *env) |
831 |
|
{ |
832 |
|
symbol *temp; |
833 |
|
int i; |
834 |
|
|
835 |
|
for(i= 0; i<HASHTBLSIZE; i++) { |
836 |
|
temp= env->symbols[i]; |
837 |
|
while(temp!=NULL) { |
838 |
|
printf("%s\n", temp->id); |
839 |
|
temp= temp->next; |
840 |
|
} |
841 |
|
} |
842 |
|
} |
843 |
|
|
844 |
|
/* Forgets a symbol (remove it from the hash table) */ |
845 |
|
extern void forget(environment *env) |
846 |
{ |
{ |
847 |
while(*stack_head!=NULL) |
char* sym_id; |
848 |
toss(stack_head); |
stackitem *stack_head= env->head; |
849 |
|
symbol **hash_entry, *temp; |
850 |
|
|
851 |
|
if(stack_head==NULL) { |
852 |
|
printerr("Too Few Arguments"); |
853 |
|
env->err=1; |
854 |
|
return; |
855 |
|
} |
856 |
|
|
857 |
|
if(stack_head->item->type!=symb) { |
858 |
|
printerr("Bad Argument Type"); |
859 |
|
env->err=2; |
860 |
|
return; |
861 |
|
} |
862 |
|
|
863 |
|
sym_id= ((symbol*)(stack_head->item->content.ptr))->id; |
864 |
|
toss(env); |
865 |
|
|
866 |
|
hash_entry= hash(env->symbols, sym_id); |
867 |
|
temp= *hash_entry; |
868 |
|
*hash_entry= (*hash_entry)->next; |
869 |
|
|
870 |
|
if(temp->val!=NULL) { |
871 |
|
free_val(temp->val); |
872 |
|
} |
873 |
|
free(temp->id); |
874 |
|
free(temp); |
875 |
|
} |
876 |
|
|
877 |
|
/* Returns the current error number to the stack */ |
878 |
|
extern void errn(environment *env){ |
879 |
|
push_int(&(env->head), env->err); |
880 |
} |
} |
881 |
|
|
882 |
int main() |
int main() |
883 |
{ |
{ |
884 |
stackitem* s= NULL; |
environment myenv; |
|
hashtbl myhash; |
|
885 |
char in_string[100]; |
char in_string[100]; |
886 |
|
|
887 |
init_hashtbl(myhash); |
init_env(&myenv); |
888 |
|
|
889 |
printf("okidok\n "); |
printf("okidok\n "); |
890 |
|
|
891 |
while(fgets(in_string, 100, stdin) != NULL) { |
while(fgets(in_string, 100, stdin) != NULL) { |
892 |
stack_read(&s, myhash, in_string); |
stack_read(&myenv, in_string); |
893 |
|
if(myenv.err) { |
894 |
|
printf("(error %d) ", myenv.err); |
895 |
|
myenv.err=0; |
896 |
|
} |
897 |
printf("okidok\n "); |
printf("okidok\n "); |
898 |
} |
} |
899 |
|
quit(&myenv); |
900 |
exit(EXIT_SUCCESS); |
return EXIT_FAILURE; |
901 |
} |
} |
902 |
|
|
903 |
/* Local Variables: */ |
/* + */ |
904 |
/* compile-command:"make CFLAGS=\"-Wall -g -rdynamic -ldl\" stack" */ |
extern void sx_2b(environment *env) { |
905 |
/* End: */ |
int a, b; |
906 |
|
size_t len; |
907 |
|
char* new_string; |
908 |
|
value *a_val, *b_val; |
909 |
|
|
910 |
|
if((env->head)==NULL || env->head->next==NULL) { |
911 |
|
printerr("Too Few Arguments"); |
912 |
|
env->err=1; |
913 |
|
return; |
914 |
|
} |
915 |
|
|
916 |
|
if(env->head->item->type==string |
917 |
|
&& env->head->next->item->type==string) { |
918 |
|
a_val= env->head->item; |
919 |
|
b_val= env->head->next->item; |
920 |
|
a_val->refcount++; |
921 |
|
b_val->refcount++; |
922 |
|
toss(env); if(env->err) return; |
923 |
|
toss(env); if(env->err) return; |
924 |
|
len= strlen(a_val->content.ptr)+strlen(b_val->content.ptr)+1; |
925 |
|
new_string= malloc(len); |
926 |
|
strcpy(new_string, b_val->content.ptr); |
927 |
|
strcat(new_string, a_val->content.ptr); |
928 |
|
free_val(a_val); free_val(b_val); |
929 |
|
push_cstring(&(env->head), new_string); |
930 |
|
free(new_string); |
931 |
|
return; |
932 |
|
} |
933 |
|
|
934 |
|
if(env->head->item->type!=integer |
935 |
|
|| env->head->next->item->type!=integer) { |
936 |
|
printerr("Bad Argument Type"); |
937 |
|
env->err=2; |
938 |
|
return; |
939 |
|
} |
940 |
|
a=env->head->item->content.val; |
941 |
|
toss(env); |
942 |
|
if(env->err) return; |
943 |
|
b=env->head->item->content.val; |
944 |
|
toss(env); |
945 |
|
if(env->err) return; |
946 |
|
push_int(&(env->head), a+b); |
947 |
|
} |