build: remove assertion messages in non-debug buildth/assert-expr-strings-bgo767296

Assertions like g_assert*() and g_return_*() contain the stringified
test expression. This string ends up in the binary and increases its
size.

We usually don't have failing assertions. These string are a waste,
instead the file and line number shall suffice.

It reduces the striped size of the NetworkManager binary from 2500k
to 2392k, that is -108k, -4.3%.

This changes

 - "g_assert (1 == 2);"
   from: NetworkManager:ERROR:source.c:347:some_function: assertion failed: (1 == 2)
   to:   NetworkManager:ERROR:source.c:347:<unknown-fcn>: assertion failed: (<dropped>)

 - "g_return_if_fail (1 == 2);"
   from: (process:21024): NetworkManager-CRITICAL **: some_function: assertion '1 == 2' failed
   to:   (process:21024): NetworkManager-CRITICAL **: ((source.c:347)): assertion '<dropped>' failed

When doing a non-debug build, those string are now removed. Debug-builds
can be enabled by setting --with-more-assert=$LEVEL to larger then zero.

https://bugzilla.gnome.org/show_bug.cgi?id=767296

2 files changed, 50 insertions, 1 deletions

diff --git a/shared/nm-default.h b/shared/nm-default.h
index aeb977a935..5d7c8f141c 100644
--- a/shared/nm-default.h
+++ b/shared/nm-default.h
@@ -53,6 +53,50 @@
 #define NM_VERSION_MIN_REQUIRED  NM_VERSION_0_9_8
 
 #include <stdlib.h>
+#include <glib.h>
+
+/*****************************************************************************/
+
+#ifndef NM_MORE_ASSERTS
+#define NM_MORE_ASSERTS 0
+#endif
+
+#if NM_MORE_ASSERTS == 0
+
+/* glib assertions (g_return_*(), g_assert*()) contain a textual representation
+ * of the checked statement. This part of the assertion blows up the size of the
+ * binary. Unless we compile a debug-build with NM_MORE_ASSERTS, drop these
+ * parts. Note that the failed assertion still prints the file and line where the
+ * assertion fails. That shall suffice. */
+
+static inline void
+_nm_g_return_if_fail_warning (const char *log_domain,
+                              const char *file,
+                              int line)
+{
+	char file_buf[256 + 15];
+
+	g_snprintf (file_buf, sizeof (file_buf), "((%s:%d))", file, line);
+	g_return_if_fail_warning (log_domain, file_buf, "<dropped>");
+}
+
+#define g_return_if_fail_warning(log_domain, pretty_function, expression) \
+	_nm_g_return_if_fail_warning (log_domain, __FILE__, __LINE__)
+
+#define g_assertion_message_expr(domain, file, line, func, expr) \
+	g_assertion_message_expr(domain, file, line, "<unknown-fcn>", (expr) ? "<dropped>" : NULL)
+
+#define NM_ASSERT_G_RETURN_EXPR(expr) "<dropped>"
+#define NM_ASSERT_NO_MSG 1
+
+#else
+
+#define NM_ASSERT_G_RETURN_EXPR(expr) ""expr""
+#define NM_ASSERT_NO_MSG 0
+
+#endif
+
+/*****************************************************************************/
 
 #include "nm-glib.h"
 #include "nm-version.h"
diff --git a/shared/nm-test-utils.h b/shared/nm-test-utils.h
index 471bf73d81..83e1f47e47 100644
--- a/shared/nm-test-utils.h
+++ b/shared/nm-test-utils.h
@@ -92,6 +92,11 @@
 
 #include "nm-default.h"
 
+#if NM_ASSERT_NO_MSG
+#undef g_return_if_fail_warning
+#undef g_assertion_message_expr
+#endif
+
 #include <arpa/inet.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -103,7 +108,7 @@
 
 /*******************************************************************************/
 
-#define NMTST_G_RETURN_MSG_S(expr) "*: assertion '"expr"' failed"
+#define NMTST_G_RETURN_MSG_S(expr) "*: assertion '"NM_ASSERT_G_RETURN_EXPR(expr)"' failed"
 #define NMTST_G_RETURN_MSG(expr)   NMTST_G_RETURN_MSG_S(#expr)
 
 /*******************************************************************************/