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-rw-r--r--gnu/usr.bin/bc/execute.c783
1 files changed, 783 insertions, 0 deletions
diff --git a/gnu/usr.bin/bc/execute.c b/gnu/usr.bin/bc/execute.c
new file mode 100644
index 000000000000..a7bc9c733520
--- /dev/null
+++ b/gnu/usr.bin/bc/execute.c
@@ -0,0 +1,783 @@
+/* execute.c - run a bc program. */
+
+/* This file is part of bc written for MINIX.
+ Copyright (C) 1991, 1992 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License , or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; see the file COPYING. If not, write to
+ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ You may contact the author by:
+ e-mail: phil@cs.wwu.edu
+ us-mail: Philip A. Nelson
+ Computer Science Department, 9062
+ Western Washington University
+ Bellingham, WA 98226-9062
+
+*************************************************************************/
+
+#include "bcdefs.h"
+#include <signal.h>
+#include "global.h"
+#include "proto.h"
+
+
+/* The SIGINT interrupt handling routine. */
+
+int had_sigint;
+
+void
+stop_execution (sig)
+ int sig;
+{
+ had_sigint = TRUE;
+ printf ("\n");
+ rt_error ("interrupted execution");
+}
+
+
+/* Get the current byte and advance the PC counter. */
+
+unsigned char
+byte (pc)
+ program_counter *pc;
+{
+ int seg, offset;
+
+ seg = pc->pc_addr >> BC_SEG_LOG;
+ offset = pc->pc_addr++ % BC_SEG_SIZE;
+ return (functions[pc->pc_func].f_body[seg][offset]);
+}
+
+
+/* The routine that actually runs the machine. */
+
+void
+execute ()
+{
+ int label_num, l_gp, l_off;
+ bc_label_group *gp;
+
+ char inst, ch;
+ int new_func;
+ int var_name;
+
+ int const_base;
+
+ bc_num temp_num;
+ arg_list *auto_list;
+
+ /* Initialize this run... */
+ pc.pc_func = 0;
+ pc.pc_addr = 0;
+ runtime_error = FALSE;
+ init_num (&temp_num);
+
+ /* Set up the interrupt mechanism for an interactive session. */
+ if (interactive)
+ {
+ signal (SIGINT, stop_execution);
+ had_sigint = FALSE;
+ }
+
+ while (pc.pc_addr < functions[pc.pc_func].f_code_size && !runtime_error)
+ {
+ inst = byte(&pc);
+
+#if DEBUG > 3
+ { /* Print out address and the stack before each instruction.*/
+ int depth; estack_rec *temp = ex_stack;
+
+ printf ("func=%d addr=%d inst=%c\n",pc.pc_func, pc.pc_addr, inst);
+ if (temp == NULL) printf ("empty stack.\n", inst);
+ else
+ {
+ depth = 1;
+ while (temp != NULL)
+ {
+ printf (" %d = ", depth);
+ out_num (temp->s_num, 10, out_char);
+ depth++;
+ temp = temp->s_next;
+ }
+ }
+ }
+#endif
+
+ switch ( inst )
+ {
+
+ case 'A' : /* increment array variable (Add one). */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ incr_array (var_name);
+ break;
+
+ case 'B' : /* Branch to a label if TOS != 0. Remove value on TOS. */
+ case 'Z' : /* Branch to a label if TOS == 0. Remove value on TOS. */
+ c_code = !is_zero (ex_stack->s_num);
+ pop ();
+ case 'J' : /* Jump to a label. */
+ label_num = byte(&pc); /* Low order bits first. */
+ label_num += byte(&pc) << 8;
+ if (inst == 'J' || (inst == 'B' && c_code)
+ || (inst == 'Z' && !c_code)) {
+ gp = functions[pc.pc_func].f_label;
+ l_gp = label_num >> BC_LABEL_LOG;
+ l_off = label_num % BC_LABEL_GROUP;
+ while (l_gp-- > 0) gp = gp->l_next;
+ pc.pc_addr = gp->l_adrs[l_off];
+ }
+ break;
+
+ case 'C' : /* Call a function. */
+ /* Get the function number. */
+ new_func = byte(&pc);
+ if ((new_func & 0x80) != 0)
+ new_func = ((new_func << 8) & 0x7f) + byte(&pc);
+
+ /* Check to make sure it is defined. */
+ if (!functions[new_func].f_defined)
+ {
+ rt_error ("Function %s not defined.", f_names[new_func]);
+ break;
+ }
+
+ /* Check and push parameters. */
+ process_params (&pc, new_func);
+
+ /* Push auto variables. */
+ for (auto_list = functions[new_func].f_autos;
+ auto_list != NULL;
+ auto_list = auto_list->next)
+ auto_var (auto_list->av_name);
+
+ /* Push pc and ibase. */
+ fpush (pc.pc_func);
+ fpush (pc.pc_addr);
+ fpush (i_base);
+
+ /* Reset pc to start of function. */
+ pc.pc_func = new_func;
+ pc.pc_addr = 0;
+ break;
+
+ case 'D' : /* Duplicate top of stack */
+ push_copy (ex_stack->s_num);
+ break;
+
+ case 'K' : /* Push a constant */
+ /* Get the input base and convert it to a bc number. */
+ if (pc.pc_func == 0)
+ const_base = i_base;
+ else
+ const_base = fn_stack->s_val;
+ if (const_base == 10)
+ push_b10_const (&pc);
+ else
+ push_constant (prog_char, const_base);
+ break;
+
+ case 'L' : /* load array variable */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ load_array (var_name);
+ break;
+
+ case 'M' : /* decrement array variable (Minus!) */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ decr_array (var_name);
+ break;
+
+ case 'O' : /* Write a string to the output with processing. */
+ while ((ch = byte(&pc)) != '"')
+ if (ch != '\\')
+ out_char (ch);
+ else
+ {
+ ch = byte(&pc);
+ if (ch == '"') break;
+ switch (ch)
+ {
+ case 'n': out_char ('\n'); break;
+ case 't': out_char ('\t'); break;
+ case 'r': out_char ('\r'); break;
+ case 'b': out_char (007); break;
+ case 'f': out_char ('\f'); break;
+ case '\\': out_char ('\\'); break;
+ default: break;
+ }
+ }
+ if (interactive) fflush (stdout);
+ break;
+
+ case 'R' : /* Return from function */
+ if (pc.pc_func != 0)
+ {
+ /* "Pop" autos and parameters. */
+ pop_vars(functions[pc.pc_func].f_autos);
+ pop_vars(functions[pc.pc_func].f_params);
+ /* reset the pc. */
+ fpop ();
+ pc.pc_addr = fpop ();
+ pc.pc_func = fpop ();
+ }
+ else
+ rt_error ("Return from main program.");
+ break;
+
+ case 'S' : /* store array variable */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ store_array (var_name);
+ break;
+
+ case 'T' : /* Test tos for zero */
+ c_code = is_zero (ex_stack->s_num);
+ assign (c_code);
+ break;
+
+ case 'W' : /* Write the value on the top of the stack. */
+ case 'P' : /* Write the value on the top of the stack. No newline. */
+ out_num (ex_stack->s_num, o_base, out_char);
+ if (inst == 'W') out_char ('\n');
+ store_var (3); /* Special variable "last". */
+ if (interactive) fflush (stdout);
+ break;
+
+ case 'c' : /* Call special function. */
+ new_func = byte(&pc);
+
+ switch (new_func)
+ {
+ case 'L': /* Length function. */
+ /* For the number 0.xxxx, 0 is not significant. */
+ if (ex_stack->s_num->n_len == 1 &&
+ ex_stack->s_num->n_scale != 0 &&
+ ex_stack->s_num->n_value[0] == 0 )
+ int2num (&ex_stack->s_num, ex_stack->s_num->n_scale);
+ else
+ int2num (&ex_stack->s_num, ex_stack->s_num->n_len
+ + ex_stack->s_num->n_scale);
+ break;
+
+ case 'S': /* Scale function. */
+ int2num (&ex_stack->s_num, ex_stack->s_num->n_scale);
+ break;
+
+ case 'R': /* Square Root function. */
+ if (!bc_sqrt (&ex_stack->s_num, scale))
+ rt_error ("Square root of a negative number");
+ break;
+
+ case 'I': /* Read function. */
+ push_constant (input_char, i_base);
+ break;
+ }
+ break;
+
+ case 'd' : /* Decrement number */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ decr_var (var_name);
+ break;
+
+ case 'h' : /* Halt the machine. */
+ exit (0);
+
+ case 'i' : /* increment number */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ incr_var (var_name);
+ break;
+
+ case 'l' : /* load variable */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ load_var (var_name);
+ break;
+
+ case 'n' : /* Negate top of stack. */
+ bc_sub (_zero_, ex_stack->s_num, &ex_stack->s_num);
+ break;
+
+ case 'p' : /* Pop the execution stack. */
+ pop ();
+ break;
+
+ case 's' : /* store variable */
+ var_name = byte(&pc);
+ if ((var_name & 0x80) != 0)
+ var_name = ((var_name << 8) & 0x7f) + byte(&pc);
+ store_var (var_name);
+ break;
+
+ case 'w' : /* Write a string to the output. */
+ while ((ch = byte(&pc)) != '"') out_char (ch);
+ if (interactive) fflush (stdout);
+ break;
+
+ case 'x' : /* Exchange Top of Stack with the one under the tos. */
+ if (check_stack(2)) {
+ bc_num temp = ex_stack->s_num;
+ ex_stack->s_num = ex_stack->s_next->s_num;
+ ex_stack->s_next->s_num = temp;
+ }
+ break;
+
+ case '0' : /* Load Constant 0. */
+ push_copy (_zero_);
+ break;
+
+ case '1' : /* Load Constant 0. */
+ push_copy (_one_);
+ break;
+
+ case '!' : /* Negate the boolean value on top of the stack. */
+ c_code = is_zero (ex_stack->s_num);
+ assign (c_code);
+ break;
+
+ case '&' : /* compare greater than */
+ if (check_stack(2))
+ {
+ c_code = !is_zero (ex_stack->s_next->s_num)
+ && !is_zero (ex_stack->s_num);
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '|' : /* compare greater than */
+ if (check_stack(2))
+ {
+ c_code = !is_zero (ex_stack->s_next->s_num)
+ || !is_zero (ex_stack->s_num);
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '+' : /* add */
+ if (check_stack(2))
+ {
+ bc_add (ex_stack->s_next->s_num, ex_stack->s_num, &temp_num);
+ pop();
+ pop();
+ push_num (temp_num);
+ init_num (&temp_num);
+ }
+ break;
+
+ case '-' : /* subtract */
+ if (check_stack(2))
+ {
+ bc_sub (ex_stack->s_next->s_num, ex_stack->s_num, &temp_num);
+ pop();
+ pop();
+ push_num (temp_num);
+ init_num (&temp_num);
+ }
+ break;
+
+ case '*' : /* multiply */
+ if (check_stack(2))
+ {
+ bc_multiply (ex_stack->s_next->s_num, ex_stack->s_num,
+ &temp_num, scale);
+ pop();
+ pop();
+ push_num (temp_num);
+ init_num (&temp_num);
+ }
+ break;
+
+ case '/' : /* divide */
+ if (check_stack(2))
+ {
+ if (bc_divide (ex_stack->s_next->s_num,
+ ex_stack->s_num, &temp_num, scale) == 0)
+ {
+ pop();
+ pop();
+ push_num (temp_num);
+ init_num (&temp_num);
+ }
+ else
+ rt_error ("Divide by zero");
+ }
+ break;
+
+ case '%' : /* remainder */
+ if (check_stack(2))
+ {
+ if (is_zero (ex_stack->s_num))
+ rt_error ("Modulo by zero");
+ else
+ {
+ bc_modulo (ex_stack->s_next->s_num,
+ ex_stack->s_num, &temp_num, scale);
+ pop();
+ pop();
+ push_num (temp_num);
+ init_num (&temp_num);
+ }
+ }
+ break;
+
+ case '^' : /* raise */
+ if (check_stack(2))
+ {
+ bc_raise (ex_stack->s_next->s_num,
+ ex_stack->s_num, &temp_num, scale);
+ if (is_zero (ex_stack->s_next->s_num) && is_neg (ex_stack->s_num))
+ rt_error ("divide by zero");
+ pop();
+ pop();
+ push_num (temp_num);
+ init_num (&temp_num);
+ }
+ break;
+
+ case '=' : /* compare equal */
+ if (check_stack(2))
+ {
+ c_code = bc_compare (ex_stack->s_next->s_num,
+ ex_stack->s_num) == 0;
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '#' : /* compare not equal */
+ if (check_stack(2))
+ {
+ c_code = bc_compare (ex_stack->s_next->s_num,
+ ex_stack->s_num) != 0;
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '<' : /* compare less than */
+ if (check_stack(2))
+ {
+ c_code = bc_compare (ex_stack->s_next->s_num,
+ ex_stack->s_num) == -1;
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '{' : /* compare less than or equal */
+ if (check_stack(2))
+ {
+ c_code = bc_compare (ex_stack->s_next->s_num,
+ ex_stack->s_num) <= 0;
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '>' : /* compare greater than */
+ if (check_stack(2))
+ {
+ c_code = bc_compare (ex_stack->s_next->s_num,
+ ex_stack->s_num) == 1;
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ case '}' : /* compare greater than or equal */
+ if (check_stack(2))
+ {
+ c_code = bc_compare (ex_stack->s_next->s_num,
+ ex_stack->s_num) >= 0;
+ pop ();
+ assign (c_code);
+ }
+ break;
+
+ default : /* error! */
+ rt_error ("bad instruction: inst=%c", inst);
+ }
+ }
+
+ /* Clean up the function stack and pop all autos/parameters. */
+ while (pc.pc_func != 0)
+ {
+ pop_vars(functions[pc.pc_func].f_autos);
+ pop_vars(functions[pc.pc_func].f_params);
+ fpop ();
+ pc.pc_addr = fpop ();
+ pc.pc_func = fpop ();
+ }
+
+ /* Clean up the execution stack. */
+ while (ex_stack != NULL) pop();
+
+ /* Clean up the interrupt stuff. */
+ if (interactive)
+ {
+ signal (SIGINT, use_quit);
+ if (had_sigint)
+ printf ("Interruption completed.\n");
+ }
+}
+
+
+/* Prog_char gets another byte from the program. It is used for
+ conversion of text constants in the code to numbers. */
+
+char
+prog_char ()
+{
+ return byte(&pc);
+}
+
+
+/* Read a character from the standard input. This function is used
+ by the "read" function. */
+
+char
+input_char ()
+{
+ char in_ch;
+
+ /* Get a character from the standard input for the read function. */
+ in_ch = getchar();
+
+ /* Check for a \ quoted newline. */
+ if (in_ch == '\\')
+ {
+ in_ch = getchar();
+ if (in_ch == '\n')
+ in_ch = getchar();
+ }
+
+ /* Classify and preprocess the input character. */
+ if (isdigit(in_ch))
+ return (in_ch - '0');
+ if (in_ch >= 'A' && in_ch <= 'F')
+ return (in_ch + 10 - 'A');
+ if (in_ch >= 'a' && in_ch <= 'f')
+ return (in_ch + 10 - 'a');
+ if (in_ch == '.' || in_ch == '+' || in_ch == '-')
+ return (in_ch);
+ if (in_ch <= ' ')
+ return (' ');
+
+ return (':');
+}
+
+
+/* Push_constant converts a sequence of input characters as returned
+ by IN_CHAR into a number. The number is pushed onto the execution
+ stack. The number is converted as a number in base CONV_BASE. */
+
+void
+push_constant (in_char, conv_base)
+ char (*in_char)(VOID);
+ int conv_base;
+{
+ int digits;
+ bc_num build, temp, result, mult, divisor;
+ char in_ch, first_ch;
+ char negative;
+
+ /* Initialize all bc numbers */
+ init_num (&temp);
+ init_num (&result);
+ init_num (&mult);
+ build = copy_num (_zero_);
+ negative = FALSE;
+
+ /* The conversion base. */
+ int2num (&mult, conv_base);
+
+ /* Get things ready. */
+ in_ch = in_char();
+ while (in_ch == ' ')
+ in_ch = in_char();
+
+ if (in_ch == '+')
+ in_ch = in_char();
+ else
+ if (in_ch == '-')
+ {
+ negative = TRUE;
+ in_ch = in_char();
+ }
+
+ /* Check for the special case of a single digit. */
+ if (in_ch < 16)
+ {
+ first_ch = in_ch;
+ in_ch = in_char();
+ if (in_ch < 16 && first_ch >= conv_base)
+ first_ch = conv_base - 1;
+ int2num (&build, (int) first_ch);
+ }
+
+ /* Convert the integer part. */
+ while (in_ch < 16)
+ {
+ if (in_ch < 16 && in_ch >= conv_base) in_ch = conv_base-1;
+ bc_multiply (build, mult, &result, 0);
+ int2num (&temp, (int) in_ch);
+ bc_add (result, temp, &build);
+ in_ch = in_char();
+ }
+ if (in_ch == '.')
+ {
+ in_ch = in_char();
+ if (in_ch >= conv_base) in_ch = conv_base-1;
+ free_num (&result);
+ free_num (&temp);
+ divisor = copy_num (_one_);
+ result = copy_num (_zero_);
+ digits = 0;
+ while (in_ch < 16)
+ {
+ bc_multiply (result, mult, &result, 0);
+ int2num (&temp, (int) in_ch);
+ bc_add (result, temp, &result);
+ bc_multiply (divisor, mult, &divisor, 0);
+ digits++;
+ in_ch = in_char();
+ if (in_ch < 16 && in_ch >= conv_base) in_ch = conv_base-1;
+ }
+ bc_divide (result, divisor, &result, digits);
+ bc_add (build, result, &build);
+ }
+
+ /* Final work. */
+ if (negative)
+ bc_sub (_zero_, build, &build);
+
+ push_num (build);
+ free_num (&temp);
+ free_num (&result);
+ free_num (&mult);
+}
+
+
+/* When converting base 10 constants from the program, we use this
+ more efficient way to convert them to numbers. PC tells where
+ the constant starts and is expected to be advanced to after
+ the constant. */
+
+void
+push_b10_const (pc)
+ program_counter *pc;
+{
+ bc_num build;
+ program_counter look_pc;
+ int kdigits, kscale;
+ char inchar;
+ char *ptr;
+
+ /* Count the digits and get things ready. */
+ look_pc = *pc;
+ kdigits = 0;
+ kscale = 0;
+ inchar = byte (&look_pc);
+ while (inchar != '.' && inchar != ':')
+ {
+ kdigits++;
+ inchar = byte(&look_pc);
+ }
+ if (inchar == '.' )
+ {
+ inchar = byte(&look_pc);
+ while (inchar != ':')
+ {
+ kscale++;
+ inchar = byte(&look_pc);
+ }
+ }
+
+ /* Get the first character again and move the pc. */
+ inchar = byte(pc);
+
+ /* Secial cases of 0, 1, and A-F single inputs. */
+ if (kdigits == 1 && kscale == 0)
+ {
+ if (inchar == 0)
+ {
+ push_copy (_zero_);
+ inchar = byte(pc);
+ return;
+ }
+ if (inchar == 1) {
+ push_copy (_one_);
+ inchar = byte(pc);
+ return;
+ }
+ if (inchar > 9)
+ {
+ init_num (&build);
+ int2num (&build, inchar);
+ push_num (build);
+ inchar = byte(pc);
+ return;
+ }
+ }
+
+ /* Build the new number. */
+ if (kdigits == 0)
+ {
+ build = new_num (1,kscale);
+ ptr = build->n_value;
+ *ptr++ = 0;
+ }
+ else
+ {
+ build = new_num (kdigits,kscale);
+ ptr = build->n_value;
+ }
+
+ while (inchar != ':')
+ {
+ if (inchar != '.')
+ if (inchar > 9)
+ *ptr++ = 9;
+ else
+ *ptr++ = inchar;
+ inchar = byte(pc);
+ }
+ push_num (build);
+}
+
+
+/* Put the correct value on the stack for C_CODE. Frees TOS num. */
+
+void
+assign (c_code)
+ char c_code;
+{
+ free_num (&ex_stack->s_num);
+ if (c_code)
+ ex_stack->s_num = copy_num (_one_);
+ else
+ ex_stack->s_num = copy_num (_zero_);
+}
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