[PATCH 3/3] buildtools/chkincs: add checks for missing C++ guards

[Bruce Richardson <bruce.richardson@intel.com>]

Simply compiling a C header with a C++ compiler is not enough to flag
missing 'extern "C"' guards. To catch missing guards, we can just use a
simple grep for the 'extern "C"' part, and error out if any files have a
miss.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---

Depends-on: series-21685 ("add missing C++ guards")
---
 buildtools/chkincs/meson.build | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/buildtools/chkincs/meson.build b/buildtools/chkincs/meson.build
index 9442235200..77ef59fb13 100644
--- a/buildtools/chkincs/meson.build
+++ b/buildtools/chkincs/meson.build
@@ -37,6 +37,16 @@ if not add_languages('cpp', required: false)
     subdir_done()
 endif

+# check for extern C in files, since this is not detected as an error by the compiler
+grep = find_program('grep', required: false)
+if grep.found()
+    errlist = run_command([grep, '--files-without-match', '^extern "C"', dpdk_chkinc_headers],
+            check: false, capture: true).stdout().split()
+    if errlist != []
+        error('Files missing C++ \'extern "C"\' guards:\n- ' + '\n- '.join(errlist))
+    endif
+endif
+
 gen_cpp_files = generator(gen_c_file_for_header,
         output: '@BASENAME@.cpp',
         arguments: ['@INPUT@', '@OUTPUT@'])
--
2.32.0