FINDERR VERSION 1.0 Ted H. Emigh Departments of Genetics and Statistics North Carolina State University Raleigh, NC 27695 usenet: emigh@ecsvax One of the major advantages of ZCPR3 is the passing of messages from one utility to the next. Unfortunately, almost all commercial packages do not have this mechanism. This program was developed to help in the passing of messages from commercial programs to ZCPR3 utilities. As an example: We may wish to have a compilation/assembly stop if there are errors. Otherwise, we may wish to link the program with a library to an executable program. Microsoft's Macro-80 assembler (M80) and FORTRAN-80 compiler (F80) give a summary of the number of fatal and warning errors just before the assembler/compiler stops execution. FINDERR looks at the fatal and warning errors from M80/F80 and sets the ZCPR3 registers if there have been any errors. Although it was designed for M80/F80, it should be relatively simple to add this type of error messages for any program that gives a summary of errors (or a total number of errors). ZCPR3 MESSAGES: ZCPR3 allows the passing and testing of messages using the IF # construct, where # is a number between 0 and 9. If a particular register is 0, then an error did not occur, if it is nonzero, then an error occured during assembly/compilation, and the specific value designates whether the error was fatal or a warning error. In this version of FINDERR, ZCPR3 Register 0 reflects the error status of a prior M80 assembly, and ZCPR3 Register 1 reflects the error status of a prior F80 compilation. FINDERR will check memory locations for both M80 and F80 -- but will be valid only ONE AT A TIME, and must be executed immediately after M80/F80. THE NATURE OF SUMMARY MESSAGES: If a program gives a summary message, it must have locations to keep track of the errors (or summary data). As the program exits, it will check these locations and print a message if it is appropriate. You need to find these locations in order to make use of the summary information. To find these locations, you need a good disassembler (RES, ZDASM, etc). FINDING SUMMARY LOCATIONS: The first thing you must look for is the message that is printed out when there is an error, say, "Errors Detected". Dump memory from 100H until you have found the message. The message, typically will end with a '$', or 0, or with the 80H bit set, or will have a single byte at the beginning which contains the number of characters to display: db 'Errors Detected',0DH,0AH,'$' ;ending in '$' db 'Errors Detected',0DH,0AH,0 ;ending in 0 db 'Errors Detected',0DH,0AH+80H ;ending with 80H bit set db 17,'Errors Detected',0DH,0AH ;character count at the start Normally, there are two ways for the program to print an error message: 1) Loading the address of the summary message into a register (e.g., LXI H,ERRMSG), then calling a routine that prints the message; or 2) Having a CALL just before the summary message (the address of the summary message is then put on the stack). The first is the most common situation. Once you have found the summary message, use your disassembler's 'FIND' function to find where the beginning location of the message has been referenced. In this area, you will find the code that checks for the error count. The following is an example (from Microsoft's M80 macro assembler, version 3.44). 2EAD LDHL 3CEDH ;Location for number of fatal errors 2EB0 MOV A,H ;See if there are errors 2EB1 ORA L 2EB2 JZ 2ECBH ;No errors, print 'No' 2EB5 PUSH H ;These next 2EB6 CALL 1ADFH ; statements 2EB9 POP H ; print the number 2EBA LDA 40B4H ; of errors 2EBD INR A 2EBE STA 3F5BH 2EC1 CNZ 1ADFH 2EC4 XRA A 2EC5 STA 3F5BH 2EC8 JMP 2ED1H ;Now print ' Fatal error(s)' 2ECB LXI H,2F4CH ;Point to 'No' message 2ECE CALL 2FD0H ;Print it 2ED1 LXI H,2F4FH ;Point to ' Fatal error(s)' message 2ED4 CALL 2FD0H ;Print it . . . 2F4C DB 'No',0 2F4F DB ' Fatal error(s)',0 In this case, I searched for 2F4CH (the 'No' message), and found it referenced at 2ECBH. The instruction just before this is an unconditional jump (JMP 2ED1H), so we need to 'FIND' 2ECBH as well. This search leads to 2EB2H, and the instructions just prior to it. We can see now that location 3CEDH is the 2-byte location for the number of errors (actually, from this segment all we know is that the word at 3CEDH is zero if there are no errors, and nonzero if there are errors). Once you understand what to look for, it is not too difficult to find these locations. Unfortunately, not all programs do this. For example, neither ASM nor MAC keep track of the number of errors, so this will not work for those assemblers. When you have found the locations, and how many bytes each takes, you can add them to this program by changing the system equates at the beginning of the program. For the distribution version, register 0 is zero if M80 found no errors, is one if M80 found at least one fatal error, and is two if M80 found no fatal errors but did find at least one warning error. In addition, register 1 is zero if F80 found no errors, is one if F80 found at least one fatal error, and is two if F80 found no fatal errors, but did find at least one warning error. USING FINDERR: FINDERR MUST be executed immediately following the termination of the program that it is checking, so that no memory locations are changed. Note that this means that FINDERR should lie in the path, don't use CMDRUN to get it out of a library, as this may change the memory locations you wish to test. The ZCPR3 registers are set IN CONTEXT WITH the program executed prior to FINDERR. Hence, Register 0 is a valid test with FINDERR after M80, but is invalid if FINDERR is executed after F80. The following ZEX file will assemble an M80 file and link/load it if there are no errors. If there are warning errors, it will wait for programmer intervention, and if there are any fatal errors it will abort the assembly. EXAMPLE: ; ; M80.ZEX -- MACRO-80 Assembler and Linker ; ; ^& Suppress FALSE IF Printout if nul $1 ;note Print Error Message echo ^G**** No Parameter Specified **** else ;note Perform Assembly if ~empty $1.MAC ;note Print File Not Found echo **** File Not Found **** else M80 =$1 FINDERR if 0 ;note No errors found, link file ERA $1.BAK ERA $1.COM L80 /P:100,$1,$1/N,SYSLIB/S,/E else ;note on IF REG 0 if 0 2 ;note see if the errors are warnings echo ^G***WARNING ERROR*** if input Type T to Continue or F to Abort (Warning Errors) ERA $1.BAK ERA $1.COM L80 /P:100,$1,$1/N,SYSLIB/S,/E fi ;note on IF INPUT else ;note error is fatal echo ^G***FATAL ERROR IN ASSEMBLY*** fi ;note IF REG 0 2 ERA $1.REL fi;fi ;note on IF NUL and IF EMPTY ; ; Assembly Complete ;  .