I've started to look at what it is required to convert the testsuite to
C99 (without implicit ints, without implicit function declarations, and
a few other legacy language features).
I plan to bundle a bunch of fixes together and submit patches
incrementally. So far, I have identified the following change
categories:
* C89 test cases that appear to make explicit use of C89-only features.
I plan to add /* { dg-additional-options "-std=gnu89" } */ to those
(or add -std=gnu89 to an existing dg-options line). These fixes can
be submitted early.
* Overly reduced test cases where I can verify that the less-reduced
test case still reproduces the bug. Can be submitted early.
* Similar test cases where I cannot verify that the test case is still
reproducing the bug, but where I assume that the unreduction is
harmless as far as the test objective is concerned. Can be submitted
early (but should be in a separate patch from the previous one).
* Test cases which have to build with -fpermissive. These include
expected-warnings tests, and over-reduced test cases where unreducing
might conceivably interfere with the test objective. These fixes have
to wait until -fpermissive for C lands (or they could wait until the
first relevant use of permerror).
* Test cases which check (for example) error locations from diagnostics
that used be warnings, but that are now errors, and other test cases
where it seems to make sense to test for errors now. Here I plan to
change dg-warning into dg-error as appropriate. These changes would
be submitted along the patch that introduces the relevant permerror
calls. In some cases, I plan to duplicate tests into warning variants
(now with -fpermissive) and error variants (with dg-warning changed to
dg-error).
* There's the matter of target-specific tests that I don't know how to
cover. I can probably run the testsuite on x86-64, POWER9 and
AArch64, but beyond that, I'm pretty much out of options. I will have
to rely on help from the community, and perhaps target maintainers
adjusting their tests after the permerror changes according to the
principles above.
Overall, I'm quite happy with the -fpermissive and permerror behavior I
see with Jason's patch so far. As far as I can tell, permerrors are
flagged in system headers, which is what we want from a distribution
perspective at least. I could get -std=gnu89 -pedantic-errors to work
(it should still flag these things as errors, as before), and -std=gnu89
-fno-permissive works out of the box, too.
(Beyond the testsuite, we will need some libgcc fixes. I've started to
submit patches for that, but they have been bogged down in discussions
how to best fix the broken code unfortunately.)
Thanks,
Florian
