From 731d4452c33647b76217ce8f6b20e69f6cc355f3 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Wed, 7 Jan 2026 08:32:54 +1000
Subject: [PATCH] meson: revamp the debug build detection for the builddir
 lookup

Ifdef out any special behavior we want so we no longer leak this via
strings in the resulting binary. Ideally we want the compile to fail for
anything missed rather than surprising behavior when we try to access
files in the build directory.

Closes: #1230
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1396>
---
 meson.build                 |  9 +++++----
 src/builddir.h              |  4 ++++
 test/test-builddir-lookup.c | 18 ++++++++----------
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/meson.build b/meson.build
index ca56c97b..68a06b28 100644
--- a/meson.build
+++ b/meson.build
@@ -80,10 +80,11 @@ endif
 config_h.set_quoted('HTTP_DOC_LINK', doc_url)
 
 config_h.set('_GNU_SOURCE', '1')
-if get_option('buildtype') == 'debug' or get_option('buildtype') == 'debugoptimized'
+
+is_debug_build = get_option('buildtype') == 'debug' or get_option('buildtype') == 'debugoptimized'
+if is_debug_build
+	config_h.set('IS_DEBUG_BUILD', '1')
 	config_h.set_quoted('MESON_BUILD_ROOT', meson.current_build_dir())
-else
-	config_h.set_quoted('MESON_BUILD_ROOT', '')
 endif
 
 prefix = '''#define _GNU_SOURCE 1
@@ -758,7 +759,7 @@ executable('ptraccel-debug',
 
 # Don't run the test during a release build because we rely on the magic
 # subtool lookup
-if get_option('buildtype') == 'debug' or get_option('buildtype') == 'debugoptimized'
+if is_debug_build
 	config_tool_option_test = configuration_data()
 	config_tool_option_test.set('DISABLE_WARNING', 'yes')
 	config_tool_option_test.set('MESON_ENABLED_DEBUG_GUI', get_option('debug-gui'))
diff --git a/src/builddir.h b/src/builddir.h
index 1f90a563..74203bdc 100644
--- a/src/builddir.h
+++ b/src/builddir.h
@@ -36,6 +36,7 @@
 static inline bool
 builddir_lookup(char **builddir)
 {
+#ifdef IS_DEBUG_BUILD
 	char execdir[PATH_MAX];
 	char *pathsep;
 	ssize_t nread;
@@ -65,4 +66,7 @@ builddir_lookup(char **builddir)
 		*builddir = safe_strdup(execdir);
 
 	return true;
+#else
+	return false;
+#endif
 }
diff --git a/test/test-builddir-lookup.c b/test/test-builddir-lookup.c
index ae118fb1..15e3eeae 100644
--- a/test/test-builddir-lookup.c
+++ b/test/test-builddir-lookup.c
@@ -40,16 +40,14 @@ main(int argc, char **argv)
 		assert(!is_builddir);
 		assert(builddir == NULL);
 	} else if (streq(mode, "--builddir-is-set")) {
-		/* In the case of release builds, the builddir is
-		   the empty string */
-		if (streq(MESON_BUILD_ROOT, "")) {
-			assert(!is_builddir);
-			assert(builddir == NULL);
-		} else {
-			assert(is_builddir);
-			assert(builddir);
-			assert(streq(MESON_BUILD_ROOT, builddir));
-		}
+#ifdef IS_DEBUG_BUILD
+		assert(is_builddir);
+		assert(builddir);
+		assert(streq(MESON_BUILD_ROOT, builddir));
+#else
+		assert(!is_builddir);
+		assert(builddir == NULL);
+#endif
 	} else {
 		abort();
 	}