Similarly to commit 64c1a544352 ("meson: Enable -Wvla") with
variable length arrays, forbid alloca() uses on system code.

There are few uses on ancient linux-user code, do not bother
there.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 meson.build | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/meson.build b/meson.build
index 0d42de61ae6..3d1dc2e9e26 100644
--- a/meson.build
+++ b/meson.build
@@ -775,6 +775,10 @@ if host_os != 'darwin'
   endif
 endif
 
+if have_system
+  warn_flags += ['-Walloca']
+endif
+
 # Set up C++ compiler flags
 qemu_cxxflags = []
 if 'cpp' in all_languages
-- 
2.51.0