Most information about potential or actual problems comes through messages
from the compiler or application program. These messages are written to the
standard error stream.
Error severity
Compilation errors can have the following severity levels, which are displayed
as part of some error messages:
U
An unrecoverable error. Compilation failed because of an internal compiler
error.
S
A severe error. Compilation failed due to one of the following:
An unrecoverable program error has been detected. Processing of the source
file stops, and XL Fortran does not produce an object file. You can usually
correct this error by fixing any program errors that were reported during
compilation.
Conditions exist that the compiler could not correct. An object file is
produced; however, you should not attempt to run the program.
An internal compiler table has overflowed. Processing of the program stops,
and XL Fortran does not produce an object file.
An include file does not exist. Processing of the program stops, and XL
Fortran does not produce an object file.
E
An error that the compiler can correct. The program should run correctly.
W
Warning message. It does not signify an error but may indicate some
unexpected condition.
L
Warning message that was generated by one of the compiler options that
check for conformance to various language levels. It may indicate a language
feature that you should avoid if you are concerned about portability.
I
Informational message. It does not indicate any error, just something
that you should be aware of to avoid unexpected behavior or to improve performance.
Notes:
The message levels S and U indicate a compilation failure.
The message levels I, L, W, and E indicate
that compilation was successful.
By default, the compiler stops without producing output files if it encounters
a severe error (severity S). You can make the compiler stop for less severe
errors by specifying a different severity with the -qhalt option.
For example, with -qhalt=e, the compiler stops if it encounters any
errors of severity E or higher severity. This technique can reduce the amount
of compilation time that is needed to check the syntactic and semantic validity
of a program. You can limit low-severity messages without stopping the compiler
by using the -qflag option. If you simply want to prevent specific
messages from going to the output stream, see -qsuppress.
Compiler return code
The compiler return codes and their respective meanings are as follows:
0
The compiler did not encounter any errors severe enough to make it stop
processing a compilation unit.
1
The compiler encountered an error of severity E or halt_severity (whichever is lower). Depending on the level of halt_severity,
the compiler might have continued processing the compilation units with errors.
40
An option error.
41
A configuration file error.
250
An out-of-memory error. The compiler cannot allocate any more memory
for its use.
251
A signal received error. An unrecoverable error or interrupt signal
is received.
252
A file-not-found error.
253
An input/output error. Cannot read or write files.
254
A fork error. Cannot create a new process.
255
An error while executing a process.
Runtime return code
If an XLF-compiled program ends abnormally, the return code to the
operating system is 1.
If the program ends normally, the return code is 0 (by default) or is MOD(digit_string,256) if the program ends because of a STOP digit_string statement.
Understanding XL Fortran messages
In addition to the diagnostic message issued, the source line and a pointer
to the position in the source line at which the error was detected are printed
or displayed if you specify the -qsource compiler option. If -qnosource is in effect, the file name, the line number, and the column
position of the error are displayed with the message.
The format of an XL Fortran diagnostic message is:
Indicates a code generation or optimization message
01
Indicates an XL Fortran common message
11-20
Indicates a Fortran-specific message
25
Indicates a runtime message from an XL Fortran application program
85
Indicates a loop-transformation message
86
Indicates an interprocedural analysis (IPA) message
nnn
Is the message number
severity_letter
Indicates how serious the problem is, as described in the preceding
section
'message text'
Is the text describing the error
Limiting the number of compile-time messages
If the compiler issues many low-severity (I or W)
messages concerning problems you are aware of or do not care about, use the -qflag option or its short form -w to limit messages to high-severity
ones:
# E, S, and U messages go in listing; U messages are displayed on screen.
xlf95 -qflag=e:u program.f
# E, S, and U messages go in listing and are displayed on screen.
xlf95 -w program.f
Selecting the language for messages
XL Fortran comes with compiler and runtime messages
in U.S. English and Japanese. If compile-time messages are appearing
in U.S. English when they should be in another language, verify that the correct
message catalogs are installed and that the LANG, LC_MESSAGES, and/or LC_ALL environment variables are set accordingly.
If a runtime message appears in the wrong language, ensure
that your program calls the setlocale routine to set the program's
locale at run time.
To determine which XL Fortran message catalogs are installed, use the
following commands to list them:
The file names of the message catalogs are the same for all supported international
languages, but they are placed in different directories.
Note:
When you run an XL Fortran program on a system without the XL Fortran message
catalogs, runtime error messages (mostly for I/O problems) are not displayed
correctly; the program prints the message number but not the associated text.
To prevent this problem, copy the XL Fortran message catalogs from /opt/ibmcmp/msg to a directory
that is part of the NLSPATH environment-variable setting on the execution
system.
