[Bug driver/38316] New: The "--help=xxx" option does not play well with -pipe or -save-temps

[justinb at math dot berkeley dot edu]

I ran into this issue running "gcc ${CFLAGS} -Q --help=optimizers", when
${CFLAGS} happened to contain -pipe.

When -pipe is turned on, the --help=xxx switch will cause the compiler to print
help to stdout, before its usual steps of dumping "help-dummy" assembly code
and letting the driver pipe its output to the assembler. For example:
$ gcc -pipe --help=target
{standard input}: Assembler messages:
{standard input}:1: Error: no such instruction: `the following options are
target specific:'
[snip]
{standard input}:88: Error: junk at end of line, first unrecognized character
is `-'

A related, but far more minor, problem occurs when -save-temps is passed with
--help=xxx. The help message is printed correctly, but afterwards the assembler
complains:
Assembler messages:
Error: can't open help-dummy.s for reading: No such file or directory

Thanks for your attention.


-- 
           Summary: The "--help=xxx" option does not play well with -pipe or
                    -save-temps
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: driver
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: justinb at math dot berkeley dot edu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38316