as: Errors

1 
1 1.7 Error and Warning Messages
1 ==============================
1 
1 'as' may write warnings and error messages to the standard error file
1 (usually your terminal).  This should not happen when a compiler runs
1 'as' automatically.  Warnings report an assumption made so that 'as'
1 could keep assembling a flawed program; errors report a grave problem
1 that stops the assembly.
1 
1    Warning messages have the format
1 
1      file_name:NNN:Warning Message Text
1 
11 (where NNN is a line number).  If both a logical file name (⇒
 '.file' File.) and a logical line number (⇒'.line' Line.) have
1 been given then they will be used, otherwise the file name and line
1 number in the current assembler source file will be used.  The message
1 text is intended to be self explanatory (in the grand Unix tradition).
1 
1    Note the file name must be set via the logical version of the '.file'
1 directive, not the DWARF2 version of the '.file' directive.  For
1 example:
1 
1        .file 2 "bar.c"
1           error_assembler_source
1        .file "foo.c"
1        .line 30
1            error_c_source
1 
1    produces this output:
1 
1        Assembler messages:
1        asm.s:2: Error: no such instruction: `error_assembler_source'
1        foo.c:31: Error: no such instruction: `error_c_source'
1 
1    Error messages have the format
1 
1      file_name:NNN:FATAL:Error Message Text
1 
1    The file name and line number are derived as for warning messages.
1 The actual message text may be rather less explanatory because many of
1 them aren't supposed to happen.
1