rust: silence unknown warnings for the sake of old compilers

Occasionally, we may need to silence warnings and clippy lints that
were only introduced in newer Rust compiler versions.  However, this
would fail when compiling with an older rustc:

error: unknown lint: `non_local_definitions`
   --> rust/qemu-api/rust-qemu-api-tests.p/structured/offset_of.rs:79:17

So by default we need to block the unknown_lints warning.  To avoid
misspelled lints or other similar issues, re-enable it in the CI job
that uses nightly rust.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 6f2bb08ecd..f9693d226b 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -47,6 +47,8 @@ meson_options_help() {
   printf "%s\n" '                           getrandom()'
   printf "%s\n" '  --enable-safe-stack      SafeStack Stack Smash Protection (requires'
   printf "%s\n" '                           clang/llvm and coroutine backend ucontext)'
+  printf "%s\n" '  --enable-strict-rust-lints'
+  printf "%s\n" '                           Enable stricter set of Rust warnings'
   printf "%s\n" '  --enable-strip           Strip targets on install'
   printf "%s\n" '  --enable-tcg-interpreter TCG with bytecode interpreter (slow)'
   printf "%s\n" '  --enable-trace-backends=CHOICES'
@@ -493,6 +495,8 @@ _meson_option_parse() {
     --disable-spice-protocol) printf "%s" -Dspice_protocol=disabled ;;
     --enable-stack-protector) printf "%s" -Dstack_protector=enabled ;;
     --disable-stack-protector) printf "%s" -Dstack_protector=disabled ;;
+    --enable-strict-rust-lints) printf "%s" -Dstrict_rust_lints=true ;;
+    --disable-strict-rust-lints) printf "%s" -Dstrict_rust_lints=false ;;
     --enable-strip) printf "%s" -Dstrip=true ;;
     --disable-strip) printf "%s" -Dstrip=false ;;
     --sysconfdir=*) quote_sh "-Dsysconfdir=$2" ;;