X-Git-Url: http://git.subgeniuskitty.com/vvhitespace/.git/blobdiff_plain/aea858380ed276bdf924c7cbcb4310ffde2a1d02..140262a9623b3c225a5135b9003526cb6b837926:/vv_interpreter.c?ds=inline

diff --git a/vv_interpreter.c b/vv_interpreter.c
index 8fac7c2..7705319 100644
--- a/vv_interpreter.c
+++ b/vv_interpreter.c
@@ -11,6 +11,7 @@
 #include <stdint.h>
 #include <sys/select.h>
 #include <getopt.h>
+#include <termios.h>
 
 #define VERSION 1
 
@@ -46,11 +47,38 @@ stdin_empty(void)
     return 1;
 }
 
+void
+set_terminal_mode(void)
+{
+    struct termios options;
+    tcgetattr(STDIN_FILENO, &options);
+    /* Create a cbreak-like environment through the following options. */
+    options.c_lflag &= ~ECHO; /* Disable echoing of input characters. */
+    options.c_lflag &= ~ICANON; /* Disable cooked/line-oriented mode. */
+    options.c_cc[VMIN] = 1;
+    options.c_cc[VTIME] = 0;
+    tcsetattr(STDIN_FILENO, TCSANOW, &options);
+}
+
+void
+unset_terminal_mode(void)
+{
+    struct termios options;
+    tcgetattr(STDIN_FILENO, &options);
+    /* Undo the changes made in set_terminal_mode(). */
+    options.c_lflag |= ECHO; /* Enable echoing of input characters. */
+    options.c_lflag |= ICANON; /* Enable cooked/line-oriented mode. */
+    options.c_cc[VMIN] = 1; /* Default value from /usr/src/sys/sys/ttydefaults.h */
+    options.c_cc[VTIME] = 0; /* Default value from /usr/src/sys/sys/ttydefaults.h */
+    tcsetattr(STDIN_FILENO, TCSANOW, &options);
+}
+
 void
 ws_die(size_t * pc, char * msg)
 {
     printf("SIM_ERROR @ PC %lu: %s\n", *pc, msg);
     fflush(stdout);
+    unset_terminal_mode();
     exit(EXIT_FAILURE);
 }
 
@@ -223,6 +251,7 @@ process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * l
         case '\n':
             /* Technically another LF is required but we ignore it. */
             fflush(stdout);
+            unset_terminal_mode();
             exit(EXIT_SUCCESS);
         case ' ':
             {
@@ -232,12 +261,15 @@ process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * l
                         if (next_code_byte(code,pc) != '\v') ws_die(pc,"expected vtab, "
                                 "perhaps a whitespace program, rather than vvhitespace?");
                         /* Jump to next instruction since labels were parsed during startup. */
-                        parse_label( code, pc);
+                        parse_label(code, pc);
                         break;
                     case '\t':
                         /* Call a subroutine. */
-                        *((*rsp)++) = *pc;
-                        *pc = labels[parse_label(code, pc)];
+                        {
+                            size_t temp_pc = labels[parse_label(code, pc)];
+                            *((*rsp)++) = *pc;
+                            *pc = temp_pc;
+                        }
                         break;
                     case '\n':
                         /* Jump unconditionally to a label. */
@@ -254,11 +286,11 @@ process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * l
                 switch (next_code_byte(code,pc)) {
                     case ' ':
                         /* Jump to a label if TOS == 0 */
-                        if (stack_peek(sp,0) == 0) *pc = labels[parse_label(code, pc)];
+                        if (stack_pop(sp) == 0) *pc = labels[parse_label(code, pc)];
                         break;
                     case '\t':
                         /* Jump to a label if TOS < 0. */
-                        if (stack_peek(sp,0) < 0) *pc = labels[parse_label(code, pc)];
+                        if (stack_pop(sp) < 0) *pc = labels[parse_label(code, pc)];
                         break;
                     case '\n':
                         /* Return from subroutine. */
@@ -306,8 +338,8 @@ process_imp_io(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp)
             /* Output */
             {
                 switch (next_code_byte(code,pc)) {
-                    case ' ' : /* Output character from TOS */ printf("%c", stack_pop(sp)); break;
-                    case '\t': /* Output number from TOS    */ printf("%d", stack_pop(sp)); break;
+                    case ' ' : /* Output char from TOS  */ printf("%c", stack_pop(sp));     break;
+                    case '\t': /* Output digit from TOS */ printf("%c", stack_pop(sp)+'0'); break;
                     default  : ws_die(pc, "malformed output IMP");                          break;
                 }
                 fflush(stdout);
@@ -320,7 +352,7 @@ process_imp_io(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp)
                 char c = getchar();
                 switch (next_code_byte(code,pc)) {
                     case '\t': /* Input digit     */ c -= '0';                /* fallthrough */
-                    case ' ' : /* Input character */ *(*hp + *((*sp)--)) = c; break;
+                    case ' ' : /* Input character */ *(*hp + *(--(*sp))) = c; break;
                     default  : ws_die(pc, "malformed input IMP");             break;
                 }
             }
@@ -397,16 +429,15 @@ main(int argc, char ** argv)
     /*
      * Main Loop
      */
-
+    set_terminal_mode();
     size_t pc = 0; /* Virtual program counter. Operates in the ws_code_space[] address space. */
     while (1) {
         if (pc >= ws_code_size) {
             fprintf(stderr, "SIM_ERROR: PC Overrun\n    Requested PC: %lu\n    Max Address: %lu\n",
                 pc, ws_code_size-1);
             exit(EXIT_FAILURE);
+            unset_terminal_mode();
         }
-// TODO: Have the SIGTERM signal handler and normal term point return the value
-// on TOS so I can do rudimentary automated tests.
 
         /* Decode the IMPs */
         switch (ws_code_space[pc++]) {
@@ -445,4 +476,5 @@ main(int argc, char ** argv)
     printf("Program executed.\n");
 
     exit(EXIT_SUCCESS);
+    unset_terminal_mode();
 }