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  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <string.h>
  4.  
  5. typedef struct label {
  6. 	char *name;
  7. 	short address;
  8. } Label;
  9.  
  10. typedef struct code {
  11. 	short opcode;
  12. 	short operand;
  13. 	int line_no;
  14. } Code;
  15.  
  16. enum { NOP, BEGIN, CALL, END, EXECUTE };
  17.  
  18. struct op {
  19. 	const char name[8];
  20. 	short code;
  21. } op_table[] = {
  22. 	{ "BEGIN"  , BEGIN },
  23. 	{ "CALL"   , CALL },
  24. 	{ "END"    , END },
  25. 	{ "EXECUTE", EXECUTE },
  26. };
  27.  
  28. #define MEMSIZE 32767
  29. #define STACKSIZE 256
  30.  
  31. int lbl_count = 0;
  32. Label label[MEMSIZE];
  33. Code   code[MEMSIZE];
  34. int   stack[STACKSIZE];
  35. int sp = -1;
  36. int pc;
  37.  
  38. void print_stack(void);
  39. char *my_strdup(char *s);
  40.  
  41. int main(void){
  42. 	FILE *fp = stdin;//fopen("code.prg", "r");
  43. 	char line[128];
  44. 	int i;
  45. 	pc = 1;
  46.  
  47. 	//convert code
  48. 	while(fgets(line, sizeof line, fp)){
  49. 		int no;
  50. 		char opname[8], operand[16];
  51. 		int ret_scnf = sscanf(line, "%d %7s %15s", &no, opname, operand);
  52. 		struct op *op = bsearch(opname, op_table,
  53. 			sizeof(op_table)/ sizeof(*op_table), sizeof(*op_table),
  54. 			(int (*)(const void *, const void *))strcmp);
  55. 		if(!op){
  56. 			printf("unknown code\n");
  57. 			continue;
  58. 		}
  59. 		switch(op->code){
  60. 		case BEGIN:
  61. 			if(ret_scnf != 3){
  62. 				printf("%s : A name is necessary.\n", line);
  63. 				continue;
  64. 			}
  65. 			for(i = 0; i < lbl_count; ++i){
  66. 				if(strcmp(operand, label[i].name) == 0)
  67. 					break;
  68. 			}
  69. 			if(i != lbl_count){//found
  70. 				int wpc = label[i].address;
  71. 				label[i].address = pc;
  72. 				while(wpc < 0){//Follow the label address link
  73. 					int next = code[-wpc].operand;
  74. 					code[-wpc].operand = pc;
  75. 					if(next != wpc){
  76. 						wpc = next;
  77. 					} else {
  78. 						break;
  79. 					}
  80. 				}
  81. 			} else {//not found
  82. 				label[lbl_count].name = my_strdup(operand);//ret_scnf == 3
  83. 				label[lbl_count++].address = pc;
  84. 			}
  85. 			code[pc].operand = pc;
  86. 			break;
  87. 		case CALL:
  88. 			if(ret_scnf != 3){
  89. 				printf("%s : A name is necessary.\n", line);
  90. 				continue;
  91. 			}
  92. 			for(i = 0; i < lbl_count; ++i){
  93. 				if(strcmp(operand, label[i].name) == 0)
  94. 					break;
  95. 			}
  96. 			if(i != lbl_count){//found
  97. 				code[pc].operand = label[i].address;
  98. 				if(label[i].address < 0){
  99. 					label[i].address = -pc;
  100. 				}
  101. 			} else {//not found
  102. 				label[lbl_count].address = code[pc].operand = -pc;
  103. 				label[lbl_count++].name = my_strdup(operand);
  104. 			}
  105. 			break;
  106. 		case END:
  107. 		case EXECUTE:
  108. 			code[pc].operand = pc;//no operand
  109. 			break;
  110. 		}
  111. 		code[pc].line_no = no;
  112. 		code[pc++].opcode = op->code;
  113. 	}
  114. 	fclose(fp);
  115. 	//check unresolve and set start address
  116. 	pc = 0;
  117. 	for(i = 0; i < lbl_count; ++i){
  118. 		if(label[i].address < 0){
  119. 			printf("%s %d\n", label[i].name, label[i].address);
  120. 			printf("There are unresolved references.\n");
  121. 			exit(EXIT_FAILURE);
  122. 		}
  123. 		if(strcmp(label[i].name, "Main")==0)
  124. 			pc = label[i].address;
  125. 		free(label[i].name);
  126. 	}
  127. 	if(!pc){
  128. 		printf("'Main' does not exist.\n");
  129. 		exit(EXIT_FAILURE);
  130. 	}
  131. 	//execute code
  132. 	sp = -1;
  133. 	int end = 0;
  134. 	while(!end){
  135. 		Code curr = code[pc];
  136. 		printf("%d", curr.line_no);
  137. 		switch(curr.opcode){
  138. 		case BEGIN:
  139. 		case EXECUTE:
  140. 			++pc;
  141. 			break;
  142. 		case CALL:
  143. 			stack[++sp] = pc;
  144. 			print_stack();
  145. 			pc = curr.operand;
  146. 			break;
  147. 		case END:
  148. 			if(sp == -1){
  149. 				printf("  --- END ---");
  150. 				end = 1;
  151. 			} else {
  152. 				pc = stack[sp--] + 1;//+1 : back to next statement
  153. 				print_stack();
  154. 			}
  155. 		}
  156. 		printf("\n");
  157. 	}
  158. }
  159.  
  160. void print_stack(void){
  161. 	printf(" Stack = ");
  162. 	for(int i = sp; i >= 0; --i){
  163. 		if(i != sp)
  164. 			printf(" ");
  165. 		printf("%d", stack[i]);
  166. 	}
  167. }
  168.  
  169. char *my_strdup(char *s){
  170. 	char *r = malloc(strlen(s)+1);
  171. 	if(r)
  172. 		strcpy(r, s);
  173. 	return r;
  174. }
Success #stdin #stdout 0s 10192KB
comments (?)
stdin 
1 BEGIN Fun1  
2  CALL Fun2 
3  EXECUTE 
4 END  
5 BEGIN Fun2  
6  EXECUTE 
7 END  
8 BEGIN Main  
9  EXECUTE 
10  CALL Fun1 
11 END
stdout 
8
9
10 Stack = 10
1
2 Stack = 2 10
5
6
7 Stack = 10
3
4 Stack = 
11  --- END ---
https://ideone.com/QotaSJ
language:
C99 (gcc 8.3)
created:
8 years ago
visibility:
public

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