--- stack/stack.c 2002/02/07 04:11:10 1.47 +++ stack/stack.c 2002/02/07 23:55:21 1.52 @@ -1,14 +1,12 @@ -/* printf */ +/* printf, sscanf, fgets, fprintf */ #include -/* EXIT_SUCCESS */ +/* exit, EXIT_SUCCESS, malloc, free */ #include /* NULL */ #include /* dlopen, dlsym, dlerror */ #include -/* assert */ -#include -/* strcat */ +/* strcmp, strcpy, strlen, strcat, strdup */ #include #define HASHTBLSIZE 65536 @@ -77,6 +75,52 @@ env->symbols[i]= NULL; } +void printerr(const char* in_string) { + fprintf(stderr, "Err: %s\n", in_string); +} + +/* Throw away a value */ +void free_val(value *val){ + stackitem *item, *temp; + + val->refcount--; /* Decrease the reference count */ + if(val->refcount == 0){ + switch (val->type){ /* and free the contents if necessary */ + case string: + free(val->content.ptr); + break; + case list: /* lists needs to be freed recursively */ + item=val->content.ptr; + while(item != NULL) { /* for all stack items */ + free_val(item->item); /* free the value */ + temp=item->next; /* save next ptr */ + free(item); /* free the stackitem */ + item=temp; /* go to next stackitem */ + } + free(val); /* Free the actual list value */ + break; + default: + break; + } + } +} + +/* Discard the top element of the stack. */ +extern void toss(environment *env) +{ + stackitem *temp= env->head; + + if((env->head)==NULL) { + printerr("Too Few Arguments"); + env->err=1; + return; + } + + free_val(env->head->item); /* Free the value */ + env->head= env->head->next; /* Remove the top stack item */ + free(temp); /* Free the old top stack item */ +} + /* Returns a pointer to a pointer to an element in the hash table. */ symbol **hash(hashtbl in_hashtbl, const char *in_string) { @@ -151,6 +195,55 @@ push(stack_head, new_item); } +/* Mangle a symbol name to a valid C identifier name */ +char *mangle_str(const char *old_string){ + char validchars[] + ="0123456789abcdef"; + char *new_string, *current; + + new_string=malloc((strlen(old_string)*2)+4); + strcpy(new_string, "sx_"); /* Stack eXternal */ + current=new_string+3; + while(old_string[0] != '\0'){ + current[0]=validchars[old_string[0]/16]; + current[1]=validchars[old_string[0]%16]; + current+=2; + old_string++; + } + current[0]='\0'; + + return new_string; /* The caller must free() it */ +} + +extern void mangle(environment *env){ + value *new_value; + char *new_string; + + if((env->head)==NULL) { + printerr("Too Few Arguments"); + env->err=1; + return; + } + + if(env->head->item->type!=string) { + printerr("Bad Argument Type"); + env->err=2; + return; + } + + new_string= mangle_str((const char *)(env->head->item->content.ptr)); + + toss(env); + if(env->err) return; + + new_value= malloc(sizeof(value)); + new_value->content.ptr= new_string; + new_value->type= string; + new_value->refcount=1; + + push_val(&(env->head), new_value); +} + /* Push a symbol onto the stack. */ void push_sym(environment *env, const char *in_string) { @@ -165,6 +258,8 @@ void *funcptr; /* A function pointer */ static void *handle= NULL; /* Dynamic linker handle */ + const char *dlerr; /* Dynamic linker error */ + char *mangled; /* Mangled function name */ /* Create a new stack item containing a new value */ new_item= malloc(sizeof(stackitem)); @@ -197,7 +292,14 @@ handle= dlopen(NULL, RTLD_LAZY); funcptr= dlsym(handle, in_string); /* Get function pointer */ - if(dlerror()==NULL) { /* If a function was found */ + dlerr=dlerror(); + if(dlerr != NULL) { /* If no function was found */ + mangled=mangle_str(in_string); + funcptr= dlsym(handle, mangled); /* try mangling it */ + free(mangled); + dlerr=dlerror(); + } + if(dlerr==NULL) { /* If a function was found */ new_fvalue= malloc(sizeof(value)); /* Create a new value */ new_fvalue->type=func; /* The new value is a function pointer */ new_fvalue->content.ptr=funcptr; /* Store function pointer */ @@ -209,52 +311,6 @@ push(&(env->head), new_item); } -void printerr(const char* in_string) { - fprintf(stderr, "Err: %s\n", in_string); -} - -/* Throw away a value */ -void free_val(value *val){ - stackitem *item, *temp; - - val->refcount--; /* Decrease the reference count */ - if(val->refcount == 0){ - switch (val->type){ /* and free the contents if necessary */ - case string: - free(val->content.ptr); - break; - case list: /* lists needs to be freed recursively */ - item=val->content.ptr; - while(item != NULL) { /* for all stack items */ - free_val(item->item); /* free the value */ - temp=item->next; /* save next ptr */ - free(item); /* free the stackitem */ - item=temp; /* go to next stackitem */ - } - free(val); /* Free the actual list value */ - break; - default: - break; - } - } -} - -/* Discard the top element of the stack. */ -extern void toss(environment *env) -{ - stackitem *temp= env->head; - - if((env->head)==NULL) { - printerr("Too Few Arguments"); - env->err=1; - return; - } - - free_val(env->head->item); /* Free the value */ - env->head= env->head->next; /* Remove the top stack item */ - free(temp); /* Free the old top stack item */ -} - /* Print newline. */ extern void nl() { @@ -473,7 +529,7 @@ toss(env); if(env->err) return; temp_string= malloc(strlen((char*)temp_val->content.ptr)+5); - strcat(temp_string, "[ "); + strcpy(temp_string, "[ "); strcat(temp_string, (char*)temp_val->content.ptr); strcat(temp_string, " ]"); stack_read(env, temp_string); @@ -843,3 +899,49 @@ quit(&myenv); return EXIT_FAILURE; } + +/* + */ +extern void sx_2b(environment *env) { + int a, b; + size_t len; + char* new_string; + value *a_val, *b_val; + + if((env->head)==NULL || env->head->next==NULL) { + printerr("Too Few Arguments"); + env->err=1; + return; + } + + if(env->head->item->type==string + && env->head->next->item->type==string) { + a_val= env->head->item; + b_val= env->head->next->item; + a_val->refcount++; + b_val->refcount++; + toss(env); if(env->err) return; + toss(env); if(env->err) return; + len= strlen(a_val->content.ptr)+strlen(b_val->content.ptr)+1; + new_string= malloc(len); + strcpy(new_string, b_val->content.ptr); + strcat(new_string, a_val->content.ptr); + free_val(a_val); free_val(b_val); + push_cstring(&(env->head), new_string); + free(new_string); + return; + } + + if(env->head->item->type!=integer + || env->head->next->item->type!=integer) { + printerr("Bad Argument Type"); + env->err=2; + return; + } + a=env->head->item->content.val; + toss(env); + if(env->err) return; + b=env->head->item->content.val; + toss(env); + if(env->err) return; + push_int(&(env->head), a+b); +}