From 88ac1a95e84998ce473d461424b81b91a0a3e3cc Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Fri, 27 May 2022 10:10:09 -0700 Subject: [PATCH v5 1/1] Introduce pg_attribute_nonnull() and use it for DefineCustomXXXVariable(). pg_attribute_nonnull() can be used to generate compiler warnings when a function is called with the specified arguments set to NULL. An empty argument list indicates that all pointer arguments must not be NULL. pg_attribute_nonnull() only works for compilers that support the nonnull function attribute. If nonnull is not supported, pg_attribute_nonnull() has no effect. In addition to introducing pg_attribute_nonnull(), this change uses it for the DefineCustomXXXVariable() functions to generate warnings when the "name" and "valueAddr" arguments are set to NULL. Idea by: Andres Freund Author: Nathan Bossart Reviewed by: Michael Paquier, Tom Lane Discussion: https://postgr.es/m/20220525061739.ur7x535vtzyzkmqo%40alap3.anarazel.de --- src/include/c.h | 11 +++++++++++ src/include/utils/guc.h | 10 +++++----- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/src/include/c.h b/src/include/c.h index 4f16e589b3..0c64557c62 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -144,6 +144,17 @@ #define pg_attribute_no_sanitize_alignment() #endif +/* + * pg_attribute_nonnull means the compiler should warn if the function is called + * with the listed arguments set to NULL. If no arguments are listed, the + * compiler should warn if any pointer arguments are set to NULL. + */ +#if __has_attribute (nonnull) +#define pg_attribute_nonnull(...) __attribute__((nonnull(__VA_ARGS__))) +#else +#define pg_attribute_nonnull(...) +#endif + /* * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only * used in assert-enabled builds, to avoid compiler warnings about unused diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h index efcbad7842..be691c5e9c 100644 --- a/src/include/utils/guc.h +++ b/src/include/utils/guc.h @@ -303,7 +303,7 @@ extern void DefineCustomBoolVariable(const char *name, int flags, GucBoolCheckHook check_hook, GucBoolAssignHook assign_hook, - GucShowHook show_hook); + GucShowHook show_hook) pg_attribute_nonnull(1, 4); extern void DefineCustomIntVariable(const char *name, const char *short_desc, @@ -316,7 +316,7 @@ extern void DefineCustomIntVariable(const char *name, int flags, GucIntCheckHook check_hook, GucIntAssignHook assign_hook, - GucShowHook show_hook); + GucShowHook show_hook) pg_attribute_nonnull(1, 4); extern void DefineCustomRealVariable(const char *name, const char *short_desc, @@ -329,7 +329,7 @@ extern void DefineCustomRealVariable(const char *name, int flags, GucRealCheckHook check_hook, GucRealAssignHook assign_hook, - GucShowHook show_hook); + GucShowHook show_hook) pg_attribute_nonnull(1, 4); extern void DefineCustomStringVariable(const char *name, const char *short_desc, @@ -340,7 +340,7 @@ extern void DefineCustomStringVariable(const char *name, int flags, GucStringCheckHook check_hook, GucStringAssignHook assign_hook, - GucShowHook show_hook); + GucShowHook show_hook) pg_attribute_nonnull(1, 4); extern void DefineCustomEnumVariable(const char *name, const char *short_desc, @@ -352,7 +352,7 @@ extern void DefineCustomEnumVariable(const char *name, int flags, GucEnumCheckHook check_hook, GucEnumAssignHook assign_hook, - GucShowHook show_hook); + GucShowHook show_hook) pg_attribute_nonnull(1, 4); extern void MarkGUCPrefixReserved(const char *className); -- 2.25.1