1 static char Sccsid[] = "@(#)fatal.c 1.4 12/22/88"; 2 3 # include "../hdr/macros.h" 4 # include "../hdr/fatal.h" 5 #include <sys/syscall.h> 6 #define syswrite(a,b,c) syscall(SYS_write,a,b,c) 7 8 /* 9 General purpose error handler. 10 Typically, low level subroutines which detect error conditions 11 (an open or create routine, for example) return the 12 value of calling fatal with an appropriate error message string. 13 E.g., return(fatal("can't do it")); 14 Higher level routines control the execution of fatal 15 via the global word Fflags. 16 The macros FSAVE and FRSTR in <fatal.h> can be used by higher 17 level subroutines to save and restore the Fflags word. 18 19 The argument to fatal is a pointer to an error message string. 20 The action of this routine is driven completely from 21 the "Fflags" global word (see <fatal.h>). 22 The following discusses the interpretation of the various bits 23 of Fflags. 24 25 The FTLMSG bit controls the writing of the error 26 message on file descriptor 2. The message is preceded 27 by the string "ERROR: ", unless the global character pointer 28 "Ffile" is non-zero, in which case the message is preceded 29 by the string "ERROR [<Ffile>]: ". A newline is written 30 after the user supplied message. 31 32 If the FTLCLN bit is on, clean_up is called with an 33 argument of 0 (see clean.c). 34 35 If the FTLFUNC bit is on, the function pointed to by the global 36 function pointer "Ffunc" is called with the user supplied 37 error message pointer as argument. 38 (This feature can be used to log error messages). 39 40 The FTLACT bits determine how fatal should return. 41 If the FTLJMP bit is on longjmp(Fjmp) is 42 called (Fjmp is a global vector of n words, see 43 setjmp, longjmp documentation). 44 45 If the FTLEXIT bit is on the value of userexit(1) is 46 passed as an argument to exit(II) 47 (see userexit.c). 48 49 If none of the FTLACT bits are on 50 (the default value for Fflags is 0), the global word 51 "Fvalue" (initialized to -1) is returned. 52 53 If all fatal globals have their default values, fatal simply 54 returns -1. 55 */ 56 57 int Fcnt; 58 int Fflags; 59 char *Ffile; 60 int Fvalue = -1; 61 int (*Ffunc)(); 62 jmp_buf Fjmp; 63 64 65 fatal(msg) 66 char *msg; 67 { 68 ++Fcnt; 69 if (Fflags & FTLMSG) { 70 syswrite(2,"ERROR",5); 71 if (Ffile) { 72 syswrite(2," [",2); 73 syswrite(2,Ffile,length(Ffile)); 74 syswrite(2,"]",1); 75 } 76 syswrite(2,": ",2); 77 syswrite(2,msg,length(msg)); 78 syswrite(2,"\n",1); 79 } 80 if (Fflags & FTLCLN) 81 clean_up(0); 82 if (Fflags & FTLFUNC) 83 (*Ffunc)(msg); 84 switch (Fflags & FTLACT) { 85 case FTLJMP: 86 longjmp(Fjmp, 1); 87 case FTLEXIT: 88 exit(userexit(1)); 89 case FTLRET: 90 return(Fvalue); 91 } 92 } 93