[PATCH v2 4/7] s390: Enhance error handling in s390-mkopc

[Jens Remus <jremus@linux.ibm.com>]

When the s390-mkopc utility detects an error it prints an error message
to strerr and either continues processing or exists with a non-zero
return code. If it continues without detecting any further error the
final return code was zero, potentially hiding the detected error.

Introduce a global variable to hold the final return code and initialize
it to EXIT_SUCCESS. Introduce a helper function print_error() that
prints an error message to stderr and sets the final return code to
EXIT_FAILURE. Use it to print all error messages. Return the final
return code at the end of the processing.

While at it enhance error messages to state more clearly which mnemonic
an error was detected for. Also continue processing for cases where
subsequent mnemonics can be processed.

opcodes/
	* s390-mkopc.c: Enhance error handling. Return EXIT_FAILURE
	  in case of an error, otherwise EXIT_SUCCESS.

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Andreas Krebbel <krebbel@linux.ibm.com>
---
 opcodes/s390-mkopc.c | 49 +++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/opcodes/s390-mkopc.c b/opcodes/s390-mkopc.c
index 5f921ee0628..aad093f18ff 100644
--- a/opcodes/s390-mkopc.c
+++ b/opcodes/s390-mkopc.c
@@ -21,9 +21,27 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <string.h>
 #include "opcode/s390.h"
 
+/* Return code.  */
+int return_code = EXIT_SUCCESS;
+
+/* Helper to print an error message and set the return code.  */
+static void __attribute__ ((format (printf, 1, 2)))
+print_error (const char *fmt, ...)
+{
+  va_list ap;
+
+  va_start(ap, fmt);
+  fprintf(stderr, "Error: ");
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+
+  return_code = EXIT_FAILURE;
+}
+
 struct op_struct
   {
     char  opcode[16];
@@ -223,8 +241,7 @@ insertExpandedMnemonic (char *opcode, char *mnemonic, char *format,
 
   if (mask_start & 3)
     {
-      fprintf (stderr, "Conditional mask not at nibble boundary in: %s\n",
-	       mnemonic);
+      print_error ("Mnemonic \"%s\": Conditional mask not at nibble boundary\n", mnemonic);
       return;
     }
 
@@ -257,7 +274,7 @@ insertExpandedMnemonic (char *opcode, char *mnemonic, char *format,
   return;
 
  malformed_mnemonic:
-  fprintf (stderr, "Malformed mnemonic: %s\n", mnemonic);
+  print_error ("Malformed mnemonic: %s\n", mnemonic);
 }
 
 static const char file_header[] =
@@ -343,8 +360,8 @@ main (void)
 		cpu_string, modes_string, flags_string);
       if (num_matched != 6 && num_matched != 7)
 	{
-	  fprintf (stderr, "Couldn't scan line %s\n", currentLine);
-	  exit (1);
+	  print_error ("Couldn't scan line %s\n", currentLine);
+	  exit (EXIT_FAILURE);
 	}
 
       if (strcmp (cpu_string, "g5") == 0
@@ -385,8 +402,9 @@ main (void)
 	       || strcmp (cpu_string, "arch14") == 0)
 	min_cpu = S390_OPCODE_ARCH14;
       else {
-	fprintf (stderr, "Couldn't parse cpu string %s\n", cpu_string);
-	exit (1);
+	print_error ("Mnemonic \"%s\": Couldn't parse CPU string: %s\n",
+		     mnemonic, cpu_string);
+	goto continue_loop;
       }
 
       str = modes_string;
@@ -401,9 +419,9 @@ main (void)
 	  mode_bits |= 1 << S390_OPCODE_ZARCH;
 	  str += 5;
 	} else {
-	  fprintf (stderr, "Couldn't parse modes string %s\n",
-		   modes_string);
-	  exit (1);
+	  print_error ("Mnemonic \"%s\": Couldn't parse modes string: %s\n",
+		       mnemonic, modes_string);
+	  goto continue_loop;
 	}
 	if (*str == ',')
 	  str++;
@@ -444,17 +462,20 @@ main (void)
 	      flag_bits |= S390_INSTR_FLAGS_CLASS_JUMPSR;
 	      str += 6;
 	    } else {
-	      fprintf (stderr, "Couldn't parse flags string %s\n",
-		       flags_string);
-	      exit (1);
+	      print_error ("Mnemonic \"%s\": Couldn't parse flags string: %s\n",
+			   mnemonic, flags_string);
+	      goto continue_loop;
 	    }
 	    if (*str == ',')
 	      str++;
 	  } while (*str != 0);
 	}
       insertExpandedMnemonic (opcode, mnemonic, format, min_cpu, mode_bits, flag_bits);
+
+ continue_loop:
+      ;
     }
 
   dumpTable ();
-  return 0;
+  return return_code;
 }
-- 
2.40.1