1 /*- 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char sccsid[] = "@(#)step.c 8.1 (Berkeley) 06/06/93"; 10 #endif /* not lint */ 11 12 /* 13 * Continue execution up to the next source line. 14 * 15 * We call "nextaddr" from the machine module to figure out 16 * what the object address is that corresponds to the next source line. 17 * If nextaddr returns -1, then the end of the program has been reached. 18 * 19 * There are two ways to define the next source line depending on what 20 * is desired when a procedure or function call is encountered. Step 21 * stops at the beginning of the procedure or call; next skips over it. 22 */ 23 24 #include "defs.h" 25 #include "process.h" 26 #include "machine.h" 27 #include "breakpoint.h" 28 #include "source.h" 29 #include "mappings.h" 30 #include "process.rep" 31 32 /* 33 * Stepc is what is called when the step command is given. 34 * It has to play with the "isstopped" information. 35 */ 36 37 stepc() 38 { 39 if (!isstopped) { 40 error("can't continue execution"); 41 } 42 isstopped = FALSE; 43 dostep(FALSE); 44 isstopped = TRUE; 45 } 46 47 next() 48 { 49 if (!isstopped) { 50 error("can't continue execution"); 51 } 52 isstopped = FALSE; 53 dostep(TRUE); 54 isstopped = TRUE; 55 } 56 57 step() 58 { 59 dostep(FALSE); 60 } 61 62 /* 63 * Resume execution up to the given address. It is assumed that 64 * no breakpoints exist between the current address and the one 65 * we're stepping to. This saves us from setting all the breakpoints. 66 */ 67 68 stepto(addr) 69 ADDRESS addr; 70 { 71 setbp(addr); 72 resume(); 73 unsetbp(addr); 74 if (!isbperr()) { 75 printstatus(); 76 } 77 } 78 79 LOCAL dostep(isnext) 80 BOOLEAN isnext; 81 { 82 register ADDRESS addr; 83 register LINENO line; 84 85 addr = pc; 86 do { 87 addr = nextaddr(addr, isnext); 88 line = linelookup(addr); 89 } while (line == 0 && !ss_instructions); 90 stepto(addr); 91 curline = line; 92 } 93