Re: [PATCH] c: don't drop typedef information in casts

[David Lamparter <equinox@diac24.net>]

On Wed, Mar 10, 2021 at 02:28:15AM +0100, David Lamparter wrote:
> The TYPE_MAIN_VARIANT() here was, for casts to a typedef'd type name,
> resulting in all information about the typedef's involvement getting
> lost.  This drops necessary information for warnings and can make them
> confusing or even misleading.  It also makes specialized warnings for
> unspecified-size system types (pid_t, uid_t, ...) impossible.

I hope I didn't produce any glaring SNAFUs in submitting this patch, I
haven't previously contributed to GCC.

I've run the testsuite on x86_64 and seen no breakage from this.  The
delta (compared to this run:
https://gcc.gnu.org/pipermail/gcc-testresults/2021-March/662078.html) is:

$ diff -U0 /tmp/before.sum /tmp/after.sum
--- /tmp/before.sum     2021-03-09 22:48:26.989146223 +0100
+++ /tmp/after.sum      2021-03-10 01:46:46.209935875 +0100
@@ -89 +89,2 @@
-FAIL: g++.old-deja/g++.other/virtual2.C  -std=c++2a execution test
+FAIL: g++.dg/modules/xtreme-header-5_c.C -std=c++17 (internal compiler error)
+FAIL: g++.dg/modules/xtreme-header-5_c.C -std=c++17 (test for excess errors)

None of which seems to be related to the patch.  (The 2 new fails are
"xtreme-header-5_c.C:3:30: internal compiler error: same canonical type node for different types 'void' and 'std::__void_t<typename _Func::is_transparent>'")

Cheers,


David