>From 352b7dede0b3a28024a41a3da1c340859b110665 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Mon, 17 Aug 2020 15:05:05 -0700 Subject: [PATCH] Update from Gnulib MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This incorporates: 2020-08-17 verify: avoid __built_assume on Clang 2020-08-17 libc-config: avoid Clang’s __diagnose_if__ * lib/cdefs.h, lib/verify.h: Copy from Gnulib. --- lib/cdefs.h | 2 +- lib/verify.h | 18 +++++++----------- 2 files changed, 8 insertions(+), 12 deletions(-) diff --git a/lib/cdefs.h b/lib/cdefs.h index 0cc27806a1..b1870fd0a9 100644 --- a/lib/cdefs.h +++ b/lib/cdefs.h @@ -148,7 +148,7 @@ #define __bos0(ptr) __builtin_object_size (ptr, 0) # define __warnattr(msg) __attribute__((__warning__ (msg))) # define __errordecl(name, msg) \ extern void name (void) __attribute__((__error__ (msg))) -#elif __glibc_clang_has_attribute (__diagnose_if__) +#elif __glibc_clang_has_attribute (__diagnose_if__) && 0 /* fails on Fedora 31 with Clang 9. */ # define __warndecl(name, msg) \ extern void name (void) __attribute__((__diagnose_if__ (1, msg, "warning"))) # define __warnattr(msg) __attribute__((__diagnose_if__ (1, msg, "warning"))) diff --git a/lib/verify.h b/lib/verify.h index 0ba8d57907..d485a0283a 100644 --- a/lib/verify.h +++ b/lib/verify.h @@ -246,13 +246,6 @@ #define _GL_VERIFY_TRUE(R, DIAGNOSTIC) \ /* @assert.h omit start@ */ -#if defined __has_builtin -/* */ -# define _GL_HAS_BUILTIN_ASSUME __has_builtin (__builtin_assume) -#else -# define _GL_HAS_BUILTIN_ASSUME 0 -#endif - #if 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__)) # define _GL_HAS_BUILTIN_TRAP 1 #elif defined __has_builtin @@ -312,11 +305,14 @@ #define verify_expr(R, E) \ Although assuming R can help a compiler generate better code or diagnostics, performance can suffer if R uses hard-to-optimize - features such as function calls not inlined by the compiler. */ + features such as function calls not inlined by the compiler. + + Avoid Clang’s __builtin_assume, as clang 9.0.1 -Wassume can + generate a bogus diagnostic "the argument to '__builtin_assume' has + side effects that will be discarded" even when the argument has no + side effects. */ -#if _GL_HAS_BUILTIN_ASSUME -# define assume(R) __builtin_assume (R) -#elif _GL_HAS_BUILTIN_UNREACHABLE +#if _GL_HAS_BUILTIN_UNREACHABLE # define assume(R) ((R) ? (void) 0 : __builtin_unreachable ()) #elif 1200 <= _MSC_VER # define assume(R) __assume (R) -- 2.17.1