Mattias Rönnblom, Oct 06, 2024 at 11:47:
OK, so it does change something, but not for the better, seemingly.
meson.build now somehow has to distinguished between two different "errors":
1) One or more offending header files were found.
2) Any other kind of error (file not found, access control issues,
internal script error, etc).
For 1), it should print a list of the offending header files.
If you just set "check: true" in run_command(), and have the
chkextern.py script return non-zero on error, the offending header files
will not be printed on stdout.
My guess would be that this complicating factor is the reason for this
pattern of not (in/from meson) depending on the script delegate exit
code, but rather the output.
May I should rename the script to "scanextern.py" to better reflect that
a failure to find an issue is not an error (=non-zero exit code).
I think you need to change run_command() to custom_target(). I was
thinking of this patch to be much simpler as follows:
diff --git a/buildtools/chkincs/check_extern_c.sh
b/buildtools/chkincs/check_extern_c.sh
new file mode 100755
index 000000000000..96ace5ffd248
--- /dev/null
+++ b/buildtools/chkincs/check_extern_c.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+# SPDX-License-Identifier: BSD-3-Clause
+
+has_symbols() {
+ grep -Eq \
+ -e 'rte_[a-z0-9_]+\(' \
+ -e 'cmdline_[a-z0-9_]+\(' \
+ -e 'vt100_[a-z0-9_]+\(' \
+ -e 'rdline_[a-z0-9_]+\(' \
+ -e 'cirbuf_[a-z0-9_]+\(' \
+ -e 'pthread_[a-z0-9_]+\(' \
+ -e 'regcomp\(' \
+ -e 'count_cpu\(' \
+ -e '^extern[[:space:]]+[a-z0-9_]+[[:space:]]' \
+ "$1"
+}
+
+has_extern_c() {
+ grep -q 'extern "C"' "$1"
+}
+
+mode=$1
+shift
+ret=0
+
+case "$mode" in
+--missing)
+ for header in "$@"; do
+ if has_symbols "$header" && ! has_extern_c "$header"; then
+ echo "error: missing extern \"C\": $header" >&2
+ ret=1
+ fi
+ done
+ ;;
+--redundant)
+ for header in "$@"; do
+ if ! has_symbols "$header" && has_extern_c "$header"; then
+ echo "error: missing extern \"C\": $header" >&2
+ exit 1
+ fi
+ done
+ ;;
+*)
+ echo "error: unsupported mode '$mode'" >&2
+ ret=1
+esac
+
+exit $ret
diff --git a/buildtools/chkincs/meson.build b/buildtools/chkincs/meson.build
index f2dadcae18ef..b463845083eb 100644
--- a/buildtools/chkincs/meson.build
+++ b/buildtools/chkincs/meson.build
@@ -38,14 +38,11 @@ if not add_languages('cpp', required: false)
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
+custom_target('check-extern-c',
+ command: files('check_extern_c.sh') + ['--missing', '@INPUT@'],
+ input: dpdk_chkinc_headers,
+ output: 'check-extern-c',
+ build_by_default: true)
gen_cpp_files = generator(gen_c_file_for_header,
output: '@BASENAME@.cpp',
