[Pam-developers] Re: [PATCH 01/33] Introduce pam_inline.h

On Fri, Mar 20, 2020 at 01:47:46PM +0100, Tomas Mraz wrote: pam_cc_compat.h was intended to be a thin compatibility layer for hiding differences between various versions of gcc and clang, with more fancy stuff going elsewhere. I renamed PAM_SAME_TYPE to PAM_IS_SAME_TYPE, introduced PAM_IS_ARRAY, and added more comments hopefully explaining things. Here is the second edition of this patch; does it address your comments? From 878e6aa471fc69b2695c00c88dcf97332933a951 Mon Sep 17 00:00:00 2001 From: "Dmitry V. Levin" <ldv(a)altlinux.org&gt; Date: Mon, 16 Mar 2020 21:02:18 +0000 Subject: [PATCH v2 01/33] Introduce pam_inline.h Introduce a new internal header file for definitions of handly inline functions and macros providing some convenient functionality to libpam and its modules. * libpam/include/pam_cc_compat.h (PAM_SAME_TYPE): New macro. * libpam/include/pam_inline.h: New file. * libpam/Makefile.am (noinst_HEADERS): Add include/pam_inline.h. --- libpam/Makefile.am | 3 ++- libpam/include/pam_cc_compat.h | 12 +++++++++++ libpam/include/pam_inline.h | 37 ++++++++++++++++++++++++++++++++++ 3 files changed, 51 insertions(+), 1 deletion(-) create mode 100644 libpam/include/pam_inline.h diff --git a/libpam/Makefile.am b/libpam/Makefile.am index bd3dc5d3..3845517f 100644 --- a/libpam/Makefile.am +++ b/libpam/Makefile.am @@ -23,7 +23,8 @@ include_HEADERS = include/security/_pam_compat.h \ include/security/pam_ext.h include/security/pam_modutil.h noinst_HEADERS = pam_prelude.h pam_private.h pam_tokens.h \ - pam_modutil_private.h include/pam_cc_compat.h + pam_modutil_private.h include/pam_cc_compat.h \ + include/pam_inline.h libpam_la_LDFLAGS = -no-undefined -version-info 85:1:85 libpam_la_LIBADD = @LIBAUDIT@ $(LIBPRELUDE_LIBS) $(ECONF_LIBS) @LIBDL@ diff --git a/libpam/include/pam_cc_compat.h b/libpam/include/pam_cc_compat.h index c43989f7..326d2eba 100644 --- a/libpam/include/pam_cc_compat.h +++ b/libpam/include/pam_cc_compat.h @@ -50,4 +50,16 @@ # define DIAG_POP_IGNORE_CAST_ALIGN /* empty */ #endif +/* + * Evaluates to + * 1, if the given two types are known to be the same + * 0, otherwise. + */ +#if PAM_GNUC_PREREQ(3, 0) +# define PAM_IS_SAME_TYPE(x_, y_) __builtin_types_compatible_p(typeof(x_), typeof(y_)) +#else +/* Cannot tell whether these types are the same. */ +# define PAM_IS_SAME_TYPE(x_, y_) 0 +#endif + #endif /* PAM_CC_COMPAT_H */ diff --git a/libpam/include/pam_inline.h b/libpam/include/pam_inline.h new file mode 100644 index 00000000..0e93b1fe --- /dev/null +++ b/libpam/include/pam_inline.h @@ -0,0 +1,37 @@ +/* + * Copyright (c) 2020 Dmitry V. Levin <ldv(a)altlinux.org&gt; + * + * Handy inline functions and macros providing some convenient functionality + * to libpam and its modules. + */ + +#ifndef PAM_INLINE_H +#define PAM_INLINE_H + +#include "pam_cc_compat.h" + +/* + * Evaluates to + * - a syntax error if the argument is 0, + * 0, otherwise. + */ +#define PAM_FAIL_BUILD_ON_ZERO(e_) (sizeof(int[-1 + 2 * !!(e_)]) * 0) + +/* + * Evaluates to + * 0, if the given type is known to be a non-array type + * 1, otherwise. + */ +#define PAM_IS_ARRAY(a_) (!PAM_IS_SAME_TYPE((a_), &(a_)[0])) + +/* + * Evaluates to + * - a syntax error if the argument is not an array, + * 0, otherwise. + */ +#define PAM_MUST_BE_ARRAY(a_) PAM_FAIL_BUILD_ON_ZERO(PAM_IS_ARRAY(a_)) + +/* Evaluates to the number of elements in the specified array. */ +#define PAM_ARRAY_SIZE(a_) (sizeof(a_) / sizeof((a_)[0]) + PAM_MUST_BE_ARRAY(a_)) + +#endif /* PAM_INLINE_H */ -- ldv