On 26/10/2023 07.51, Warner Losh wrote:
On Wed, Oct 25, 2023, 11:31 PM Markus Armbruster <arm...@redhat.com
<mailto:arm...@redhat.com>> wrote:
Local variables shadowing other local variables or parameters make the
code needlessly hard to understand. Bugs love to hide in such code.
Evidence: commit bbde656263d (migration/rdma: Fix save_page method to
fail on polling error).
Enable -Wshadow=local to prevent such issues. Possible thanks to
recent cleanups. Enabling -Wshadow would prevent more issues, but
we're not yet ready for that.
As usual, the warning is only enabled when the compiler recognizes it.
GCC does, Clang doesn't.
Some shadowed locals remain in bsd-user. Since BSD prefers Clang,
let's not wait for its cleanup.
Signed-off-by: Markus Armbruster <arm...@redhat.com
<mailto:arm...@redhat.com>>
---
meson.build | 1 +
1 file changed, 1 insertion(+)
diff --git a/meson.build b/meson.build
index dcef8b1e79..89220443b8 100644
--- a/meson.build
+++ b/meson.build
@@ -462,6 +462,7 @@ warn_flags = [
'-Wno-tautological-type-limit-compare',
'-Wno-psabi',
'-Wno-gnu-variable-sized-type-not-at-end',
+ '-Wshadow=local',
Does this work with clang? I've not had good luck enabling it.
The flags are added via cc.get_supported_arguments(warn_flags), so meson
checks whether the compiler supports them before blindly adding them to the
list.
That means it should get ignored with Clang, i.e. we should be ok for the
remaining spots in the bsd-user code, assuming that most FreeBSD users will
use Clang to compile QEMU.
Thomas