meson: tolerate errors from git ls-files --deduplicate

When using the Meson build system with versions of Git before 2.31,
that does not yet know the `git ls-files --deduplicate` option, one
can observe the following error:

    ../meson.build:697:19: ERROR: Command `/usr/bin/git -C /home/martin/code/git ls-files --deduplicate '*.h' ':!contrib' ':!compat/inet_ntop.c' ':!compat/inet_pton.c' ':!compat/nedmalloc' ':!compat/obstack.*' ':!compat/poll' ':!compat/regex' ':!sha1collisiondetection' ':!sha1dc' ':!t/unit-tests/clar' ':!t/t[0-9][0-9][0-9][0-9]*' ':!xdiff'` failed with status 129.

The failing command is used to find all header files in our code
base, which is required for static analysis.

Static analysis is an entirely optional feature that distributors
typically don't care about, and we already know to skip running the
command when we are not in a Git repository. But we do not handle
the above failure gracefully, even though we could.

Fix this by passing `check: false` to `run_command`, which makes it
tolerate failures. Then check `returncode()` manually to decide
whether to inspect the output.

Signed-off-by: Martin Storsjö <martin@martin.st>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/meson.build b/meson.build
index 596f5ac7110ebf608ced79dc335226d10a09b4a8..9b6462005652b1166612c5e0bc39423b7013f845 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -694,9 +694,14 @@ third_party_excludes = [
 
 headers_to_check = []
 if git.found() and fs.exists(meson.project_source_root() / '.git')
-  foreach header : run_command(git, '-C', meson.project_source_root(), 'ls-files', '--deduplicate', '*.h', third_party_excludes, check: true).stdout().split()
-    headers_to_check += header
-  endforeach
+  ls_headers = run_command(git, '-C', meson.project_source_root(), 'ls-files', '--deduplicate', '*.h', third_party_excludes, check: false)
+  if ls_headers.returncode() == 0
+    foreach header : ls_headers.stdout().split()
+      headers_to_check += header
+    endforeach
+  else
+    warning('could not list headers, disabling static analysis targets')
+  endif
 endif
 
 if not get_option('breaking_changes')