6 |
#include <stddef.h> |
#include <stddef.h> |
7 |
/* dlopen, dlsym, dlerror */ |
/* dlopen, dlsym, dlerror */ |
8 |
#include <dlfcn.h> |
#include <dlfcn.h> |
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/* assert */ |
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#include <assert.h> |
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#define HASHTBLSIZE 65536 |
#define HASHTBLSIZE 65536 |
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typedef struct stack_item |
typedef struct stack_item |
15 |
{ |
{ |
16 |
enum {value, string, ref, func, symbol, list} type; |
enum { |
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value, /* Integer */ |
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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 */ |
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symbol, |
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list |
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} type; /* Type of stack element */ |
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|
26 |
union { |
union { |
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void* ptr; |
void* ptr; /* Pointer to the content */ |
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int val; |
int val; /* ...or an integer */ |
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} content; |
} content; /* Stores a pointer or an integer */ |
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|
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char* id; |
char* id; /* Symbol name */ |
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struct stack_item* next; |
struct stack_item* next; /* Next element */ |
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} stackitem; |
} stackitem; |
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typedef stackitem* hashtbl[HASHTBLSIZE]; |
typedef stackitem* hashtbl[HASHTBLSIZE]; /* Hash table declaration */ |
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typedef void (*funcp)(stackitem**); |
typedef void (*funcp)(stackitem**); /* funcp is a pointer to a |
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void function (stackitem **) */ |
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|
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/* Initialize a newly created hash table. */ |
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void init_hashtbl(hashtbl out_hash) |
void init_hashtbl(hashtbl out_hash) |
42 |
{ |
{ |
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long i; |
long i; |
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out_hash[i]= NULL; |
out_hash[i]= NULL; |
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} |
} |
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|
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/* Returns a pointer to an element in the hash table. */ |
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stackitem** hash(hashtbl in_hashtbl, const char* in_string) |
stackitem** hash(hashtbl in_hashtbl, const char* in_string) |
51 |
{ |
{ |
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long i= 0; |
long i= 0; |
53 |
unsigned long out_hash= 0; |
unsigned long out_hash= 0; |
54 |
char key= 0; |
char key= '\0'; |
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stackitem** position; |
stackitem** position; |
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|
57 |
while(1){ |
while(1){ /* Hash in_string */ |
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key= in_string[i++]; |
key= in_string[i++]; |
59 |
if(key=='\0') |
if(key=='\0') |
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break; |
break; |
65 |
position= &(in_hashtbl[out_hash]); |
position= &(in_hashtbl[out_hash]); |
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|
67 |
while(1){ |
while(1){ |
68 |
if(*position==NULL) |
if(*position==NULL) /* If empty */ |
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return position; |
return position; |
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|
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if(strcmp(in_string, (*position)->id)==0) |
if(strcmp(in_string, (*position)->id)==0) /* If match */ |
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return position; |
return position; |
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|
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position= &((*position)->next); |
position= &((*position)->next); /* Try next */ |
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} |
} |
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} |
} |
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|
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/* Generic push function. */ |
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int push(stackitem** stack_head, stackitem* in_item) |
int 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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return 1; |
return 1; |
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} |
} |
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|
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/* Push a value on the stack. */ |
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int push_val(stackitem** stack_head, int in_val) |
int push_val(stackitem** stack_head, int in_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); |
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new_item->content.val= in_val; |
new_item->content.val= in_val; |
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new_item->type= value; |
new_item->type= value; |
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|
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return 1; |
return 1; |
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} |
} |
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/* Copy a string onto the stack. */ |
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int push_cstring(stackitem** stack_head, const char* in_string) |
int push_cstring(stackitem** stack_head, const char* in_string) |
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{ |
{ |
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stackitem* new_item= malloc(sizeof(stackitem)); |
stackitem* new_item= malloc(sizeof(stackitem)); |
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return 1; |
return 1; |
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} |
} |
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|
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/* Create a new hash entry. */ |
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int mk_hashentry(hashtbl in_hashtbl, stackitem* in_item, const char* id) |
int mk_hashentry(hashtbl in_hashtbl, stackitem* in_item, const char* id) |
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{ |
{ |
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in_item->id= malloc(strlen(id)+1); |
in_item->id= malloc(strlen(id)+1); |
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return 1; |
return 1; |
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} |
} |
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|
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/* Define a new function in the hash table. */ |
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void def_func(hashtbl in_hashtbl, funcp in_func, const char* id) |
void def_func(hashtbl in_hashtbl, funcp in_func, const char* id) |
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{ |
{ |
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stackitem* temp= malloc(sizeof(stackitem)); |
stackitem* temp= malloc(sizeof(stackitem)); |
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mk_hashentry(in_hashtbl, temp, id); |
mk_hashentry(in_hashtbl, temp, id); |
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} |
} |
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|
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/* Define a new symbol in the hash table. */ |
133 |
void def_sym(hashtbl in_hashtbl, const char* id) |
void def_sym(hashtbl in_hashtbl, const char* id) |
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{ |
{ |
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stackitem* temp= malloc(sizeof(stackitem)); |
stackitem* temp= malloc(sizeof(stackitem)); |
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|
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temp->type= symbol; |
temp->type= symbol; |
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mk_hashentry(in_hashtbl, temp, id); |
mk_hashentry(in_hashtbl, temp, id); |
139 |
} |
} |
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|
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/* Push a reference to an entry in the hash table onto the stack. */ |
142 |
int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string) |
int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string) |
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{ |
{ |
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static void* handle= NULL; |
static void* handle= NULL; |
148 |
new_item->content.ptr= *hash(in_hash, in_string); |
new_item->content.ptr= *hash(in_hash, in_string); |
149 |
new_item->type= ref; |
new_item->type= ref; |
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|
151 |
if(new_item->content.ptr==NULL) { |
if(new_item->content.ptr==NULL) { /* If hash entry empty */ |
152 |
if(handle==NULL) |
if(handle==NULL) /* If no handle */ |
153 |
handle= dlopen(NULL, RTLD_LAZY); |
handle= dlopen(NULL, RTLD_LAZY); |
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|
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symbol= dlsym(handle, in_string); |
symbol= dlsym(handle, in_string); /* Get function pointer */ |
156 |
if(dlerror()==NULL) |
if(dlerror()==NULL) /* If existing function pointer */ |
157 |
def_func(in_hash, symbol, in_string); |
def_func(in_hash, symbol, in_string); /* Store function pointer */ |
158 |
else |
else |
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def_sym(in_hash, in_string); |
def_sym(in_hash, in_string); /* Make symbol */ |
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|
161 |
new_item->content.ptr= *hash(in_hash, in_string); |
new_item->content.ptr= *hash(in_hash, in_string); /* The new reference |
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shouldn't point at |
163 |
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NULL */ |
164 |
new_item->type= ref; |
new_item->type= ref; |
165 |
} |
} |
166 |
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|
168 |
return 1; |
return 1; |
169 |
} |
} |
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void printerr(const char* in_string) { |
172 |
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fprintf(stderr, "Err: %s\n", in_string); |
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} |
174 |
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/* Discard the top element of the stack. */ |
176 |
extern void toss(stackitem** stack_head) |
extern void toss(stackitem** stack_head) |
177 |
{ |
{ |
178 |
stackitem* temp= *stack_head; |
stackitem* temp= *stack_head; |
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|
180 |
if((*stack_head)==NULL) |
if((*stack_head)==NULL) { |
181 |
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printerr("Stack empty"); |
182 |
return; |
return; |
183 |
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} |
184 |
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|
185 |
if((*stack_head)->type==string) |
if((*stack_head)->type==string) |
186 |
free((*stack_head)->content.ptr); |
free((*stack_head)->content.ptr); |
189 |
free(temp); |
free(temp); |
190 |
} |
} |
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|
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/* Print newline. */ |
193 |
extern void nl() |
extern void nl() |
194 |
{ |
{ |
195 |
printf("\n"); |
printf("\n"); |
196 |
} |
} |
197 |
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|
198 |
void print_(stackitem** stack_head) |
/* Prints the top element of the stack. */ |
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extern void print_(stackitem** stack_head) |
200 |
{ |
{ |
201 |
if((*stack_head)==NULL) |
stackitem* temp= *stack_head; |
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|
203 |
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if(temp==NULL) { |
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printerr("Stack empty"); |
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return; |
return; |
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} |
207 |
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|
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switch((*stack_head)->type) { |
while(temp->type==ref) |
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temp= temp->content.ptr; |
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|
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switch(temp->type) { |
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case value: |
case value: |
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printf("%d", (*stack_head)->content.val); |
printf("%d", temp->content.val); |
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break; |
break; |
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case string: |
case string: |
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printf("%s", (char*)(*stack_head)->content.ptr); |
printf("\"%s\"", (char*)temp->content.ptr); |
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break; |
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case ref: |
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printf("%s", ((stackitem*)(*stack_head)->content.ptr)->id); |
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break; |
break; |
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case symbol: |
case symbol: |
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case func: |
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printf("%s", temp->id); |
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break; |
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default: |
default: |
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printf("%p", (*stack_head)->content.ptr); |
printf("%p", temp->content.ptr); |
224 |
break; |
break; |
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} |
} |
226 |
} |
} |
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/* Prints the top element of the stack and then discards it. */ |
229 |
extern void print(stackitem** stack_head) |
extern void print(stackitem** stack_head) |
230 |
{ |
{ |
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print_(stack_head); |
print_(stack_head); |
232 |
toss(stack_head); |
toss(stack_head); |
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} |
} |
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|
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/* print_stack(stack); */ |
/* Only to be called by function printstack. */ |
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void print_st(stackitem* stack_head, long counter) |
void print_st(stackitem* stack_head, long counter) |
237 |
{ |
{ |
238 |
if(stack_head->next != NULL) |
if(stack_head->next != NULL) |
243 |
nl(); |
nl(); |
244 |
} |
} |
245 |
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|
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/* Prints the stack. */ |
247 |
extern void printstack(stackitem** stack_head) |
extern void printstack(stackitem** stack_head) |
248 |
{ |
{ |
249 |
if(*stack_head != NULL) { |
if(*stack_head != NULL) { |
250 |
print_st(*stack_head, 1); |
print_st(*stack_head, 1); |
251 |
printf("\n"); |
nl(); |
252 |
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} else { |
253 |
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printerr("Stack empty"); |
254 |
} |
} |
255 |
} |
} |
256 |
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|
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/* If the top element is a reference, determine if it's a reference to a |
258 |
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function, and if it is, toss the reference and execute the function. */ |
259 |
extern void eval(stackitem** stack_head) |
extern void eval(stackitem** stack_head) |
260 |
{ |
{ |
261 |
funcp in_func; |
funcp in_func; |
262 |
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stackitem* temp= *stack_head; |
263 |
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|
264 |
if((*stack_head)==NULL || (*stack_head)->type!=ref) |
if(temp==NULL) { |
265 |
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printerr("Stack empty"); |
266 |
return; |
return; |
267 |
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} |
268 |
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|
269 |
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while(temp->type==ref) |
270 |
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temp= temp->content.ptr; |
271 |
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|
272 |
if(((stackitem*)(*stack_head)->content.ptr)->type==func) { |
if(temp->type==func) { |
273 |
in_func= (funcp)((stackitem*)(*stack_head)->content.ptr)->content.ptr; |
in_func= (funcp)(temp->content.ptr); |
274 |
toss(stack_head); |
toss(stack_head); |
275 |
(*in_func)(stack_head); |
(*in_func)(stack_head); |
276 |
return; |
return; |
277 |
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} |
278 |
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|
279 |
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printerr("Couldn't evaluate"); |
280 |
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} |
281 |
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|
282 |
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/* Make a list. */ |
283 |
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extern void pack(stackitem** stack_head) |
284 |
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{ |
285 |
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void* delimiter; |
286 |
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stackitem *iterator, *temp, *pack; |
287 |
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288 |
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delimiter= (*stack_head)->content.ptr; /* Get delimiter */ |
289 |
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toss(stack_head); |
290 |
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|
291 |
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iterator= *stack_head; |
292 |
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|
293 |
|
if(iterator==NULL || iterator->content.ptr==delimiter) { |
294 |
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temp= NULL; |
295 |
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toss(stack_head); |
296 |
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} else { |
297 |
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/* Search for first delimiter */ |
298 |
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while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter) |
299 |
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iterator= iterator->next; |
300 |
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|
301 |
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/* Extract list */ |
302 |
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temp= *stack_head; |
303 |
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*stack_head= iterator->next; |
304 |
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iterator->next= NULL; |
305 |
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|
306 |
|
if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter) |
307 |
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toss(stack_head); |
308 |
} |
} |
309 |
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|
310 |
|
/* Push list */ |
311 |
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pack= malloc(sizeof(stackitem)); |
312 |
|
pack->type= list; |
313 |
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pack->content.ptr= temp; |
314 |
|
|
315 |
|
push(stack_head, pack); |
316 |
} |
} |
317 |
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|
318 |
|
/* Parse input. */ |
319 |
int stack_read(stackitem** stack_head, hashtbl in_hash, char* in_line) |
int stack_read(stackitem** stack_head, hashtbl in_hash, char* in_line) |
320 |
{ |
{ |
321 |
char *temp, *rest; |
char *temp, *rest; |
322 |
int itemp; |
int itemp; |
323 |
size_t inlength= strlen(in_line)+1; |
size_t inlength= strlen(in_line)+1; |
324 |
int convert= 0; |
int convert= 0; |
325 |
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static int non_eval_flag= 0; |
326 |
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|
327 |
temp= malloc(inlength); |
temp= malloc(inlength); |
328 |
rest= malloc(inlength); |
rest= malloc(inlength); |
329 |
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|
330 |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest)) >= 1) |
do { |
331 |
push_cstring(stack_head, temp); |
/* If string */ |
332 |
else if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest)) >= 1) |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
333 |
push_val(stack_head, itemp); |
push_cstring(stack_head, temp); |
334 |
else if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest)) >= 1) { |
break; |
335 |
temp[1]= '\0'; push_ref(stack_head, in_hash, temp); |
} |
336 |
} else if((convert= sscanf(in_line, "%[^ ;\n\r]%[^\n\r]", temp, rest)) >= 1) |
/* If value */ |
337 |
push_ref(stack_head, in_hash, temp); |
if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest))) { |
338 |
else if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest)) >= 1) |
push_val(stack_head, itemp); |
339 |
if(*temp==';') |
break; |
340 |
eval(stack_head); |
} |
341 |
|
/* Escape ';' with '\' */ |
342 |
|
if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest))) { |
343 |
|
temp[1]= '\0'; |
344 |
|
push_ref(stack_head, in_hash, temp); |
345 |
|
break; |
346 |
|
} |
347 |
|
/* If symbol */ |
348 |
|
if((convert= sscanf(in_line, "%[^][ ;\n\r]%[^\n\r]", temp, rest))) { |
349 |
|
push_ref(stack_head, in_hash, temp); |
350 |
|
break; |
351 |
|
} |
352 |
|
/* If single char */ |
353 |
|
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
354 |
|
if(*temp==';') { |
355 |
|
if(!non_eval_flag) { |
356 |
|
eval(stack_head); /* Evaluate top element */ |
357 |
|
break; |
358 |
|
} |
359 |
|
|
360 |
|
push_ref(stack_head, in_hash, ";"); |
361 |
|
break; |
362 |
|
} |
363 |
|
|
364 |
|
if(*temp==']') { |
365 |
|
push_ref(stack_head, in_hash, "["); |
366 |
|
pack(stack_head); |
367 |
|
if(non_eval_flag!=0) |
368 |
|
non_eval_flag--; |
369 |
|
break; |
370 |
|
} |
371 |
|
|
372 |
|
if(*temp=='[') { |
373 |
|
push_ref(stack_head, in_hash, "["); |
374 |
|
non_eval_flag++; |
375 |
|
break; |
376 |
|
} |
377 |
|
} |
378 |
|
} while(0); |
379 |
|
|
380 |
|
|
381 |
free(temp); |
free(temp); |
382 |
|
|
391 |
return 1; |
return 1; |
392 |
} |
} |
393 |
|
|
394 |
extern void pack(stackitem** stack_head) |
/* Relocate elements of the list on the stack. */ |
|
{ |
|
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void* delimiter; |
|
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stackitem *iterator, *temp, *pack; |
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|
|
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if((*stack_head)==NULL) |
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return; |
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|
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delimiter= (*stack_head)->content.ptr; |
|
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toss(stack_head); |
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|
|
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iterator= *stack_head; |
|
|
|
|
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while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter) |
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iterator= iterator->next; |
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|
|
|
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temp= *stack_head; |
|
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*stack_head= iterator->next; |
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iterator->next= NULL; |
|
|
|
|
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if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter) |
|
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toss(stack_head); |
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|
|
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pack= malloc(sizeof(stackitem)); |
|
|
pack->type= list; |
|
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pack->content.ptr= temp; |
|
|
|
|
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push(stack_head, pack); |
|
|
} |
|
|
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|
395 |
extern void expand(stackitem** stack_head) |
extern void expand(stackitem** stack_head) |
396 |
{ |
{ |
397 |
stackitem *temp, *new_head; |
stackitem *temp, *new_head; |
398 |
|
|
399 |
if((*stack_head)==NULL || (*stack_head)->type!=list) |
/* Is top element a list? */ |
400 |
|
if((*stack_head)==NULL || (*stack_head)->type!=list) { |
401 |
|
printerr("Stack empty or not a list"); |
402 |
return; |
return; |
403 |
|
} |
404 |
|
|
405 |
|
/* The first list element is the new stack head */ |
406 |
new_head= temp= (*stack_head)->content.ptr; |
new_head= temp= (*stack_head)->content.ptr; |
407 |
toss(stack_head); |
toss(stack_head); |
408 |
|
|
409 |
|
if(temp==NULL) |
410 |
|
return; |
411 |
|
|
412 |
|
/* Search the end of the list */ |
413 |
while(temp->next!=NULL) |
while(temp->next!=NULL) |
414 |
temp= temp->next; |
temp= temp->next; |
415 |
|
|
416 |
|
/* Connect the the tail of the list with the old stack head */ |
417 |
temp->next= *stack_head; |
temp->next= *stack_head; |
418 |
*stack_head= new_head; |
*stack_head= new_head; /* ...and voila! */ |
419 |
} |
} |
420 |
|
|
421 |
|
/* Swap the two top elements on the stack. */ |
422 |
extern void swap(stackitem** stack_head) |
extern void swap(stackitem** stack_head) |
423 |
{ |
{ |
424 |
stackitem* temp= (*stack_head); |
stackitem* temp= (*stack_head); |
425 |
|
|
426 |
if((*stack_head)==NULL || (*stack_head)->next==NULL) |
if((*stack_head)==NULL) { |
427 |
|
printerr("Stack empty"); |
428 |
|
return; |
429 |
|
} |
430 |
|
|
431 |
|
if((*stack_head)->next==NULL) |
432 |
return; |
return; |
433 |
|
|
434 |
*stack_head= (*stack_head)->next; |
*stack_head= (*stack_head)->next; |
436 |
(*stack_head)->next= temp; |
(*stack_head)->next= temp; |
437 |
} |
} |
438 |
|
|
439 |
|
/* Compares two elements by reference. */ |
440 |
extern void eq(stackitem** stack_head) |
extern void eq(stackitem** stack_head) |
441 |
{ |
{ |
442 |
void *left, *right; |
void *left, *right; |
443 |
int result; |
int result; |
444 |
|
|
445 |
if((*stack_head)==NULL || (*stack_head)->next==NULL) |
if((*stack_head)==NULL || (*stack_head)->next==NULL) { |
446 |
|
printerr("Not enough elements to compare"); |
447 |
return; |
return; |
448 |
|
} |
449 |
|
|
450 |
left= (*stack_head)->content.ptr; |
left= (*stack_head)->content.ptr; |
451 |
swap(stack_head); |
swap(stack_head); |
456 |
push_val(stack_head, (left==right)); |
push_val(stack_head, (left==right)); |
457 |
} |
} |
458 |
|
|
459 |
|
/* Negates the top element on the stack. */ |
460 |
extern void not(stackitem** stack_head) |
extern void not(stackitem** stack_head) |
461 |
{ |
{ |
462 |
int value; |
int value; |
463 |
|
|
464 |
if((*stack_head)==NULL) |
if((*stack_head)==NULL || (*stack_head)->type!=value) { |
465 |
|
printerr("Stack empty or element is not a value"); |
466 |
return; |
return; |
467 |
|
} |
468 |
|
|
469 |
value= (*stack_head)->content.val; |
value= (*stack_head)->content.val; |
470 |
toss(stack_head); |
toss(stack_head); |
471 |
push_val(stack_head, !value); |
push_val(stack_head, !value); |
472 |
} |
} |
473 |
|
|
474 |
|
/* Compares the two top elements on the stack and return 0 if they're the |
475 |
|
same. */ |
476 |
extern void neq(stackitem** stack_head) |
extern void neq(stackitem** stack_head) |
477 |
{ |
{ |
478 |
eq(stack_head); |
eq(stack_head); |
479 |
not(stack_head); |
not(stack_head); |
480 |
} |
} |
481 |
|
|
482 |
|
/* Give a symbol some content. */ |
483 |
extern void def(stackitem** stack_head) |
extern void def(stackitem** stack_head) |
484 |
{ |
{ |
485 |
stackitem *temp, *value; |
stackitem *temp, *value; |
486 |
|
|
487 |
if(*stack_head==NULL || (*stack_head)->next==NULL |
if(*stack_head==NULL || (*stack_head)->next==NULL |
488 |
|| (*stack_head)->type!=ref) |
|| (*stack_head)->type!=ref) { |
489 |
|
printerr("Define what?"); |
490 |
return; |
return; |
491 |
|
} |
492 |
|
|
493 |
temp= (*stack_head)->content.ptr; |
temp= (*stack_head)->content.ptr; |
494 |
value= (*stack_head)->next; |
value= (*stack_head)->next; |
499 |
toss(stack_head); toss(stack_head); |
toss(stack_head); toss(stack_head); |
500 |
} |
} |
501 |
|
|
502 |
|
/* Quit stack. */ |
503 |
extern void quit() |
extern void quit() |
504 |
{ |
{ |
505 |
exit(EXIT_SUCCESS); |
exit(EXIT_SUCCESS); |
506 |
} |
} |
507 |
|
|
508 |
|
/* Clear stack */ |
509 |
|
extern void clear(stackitem** stack_head) |
510 |
|
{ |
511 |
|
while(*stack_head!=NULL) |
512 |
|
toss(stack_head); |
513 |
|
} |
514 |
|
|
515 |
int main() |
int main() |
516 |
{ |
{ |
517 |
stackitem* s= NULL; |
stackitem* s= NULL; |