[Bug target/89517] New: [8/9 Regression] AArch64's configure option --with-arch can silently lead to incorrectly configured compiler

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89517

            Bug ID: 89517
           Summary: [8/9 Regression] AArch64's configure option
                    --with-arch can silently lead to incorrectly
                    configured compiler
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tnfchris at gcc dot gnu.org
  Target Milestone: ---

The options definition file for aarch64 is parsed by a series of regular
expressions and sed calls in config.gcc based on a couple of hard rules.

One of them is that all the options should be on one line.  From GCC 8 the
lines
were broken up and wrapped to 80 characters but this lead the grep statements
to only select the first line from the options.

This leads to the compiler silently enabling only a subset of features or none
at all when you use --with-arch during configure.