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190 lines
7.1 KiB
190 lines
7.1 KiB
commit 602f80ec8b966cfad3b61914cbe14ee606cedf6e |
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Author: Siddhesh Poyarekar <siddhesh@redhat.com> |
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Date: Tue Sep 16 22:16:01 2014 +0530 |
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Make __extern_always_inline usable on clang++ again |
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The fix for BZ #17266 (884ddc5081278f488ef8cd49951f41cfdbb480ce) |
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removed changes that had gone into cdefs.h to make |
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__extern_always_inline usable with clang++. This patch adds back |
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support for clang to detect if GNU inlining semantics are available, |
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this time without breaking the gcc use case. The check put here is |
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based on the earlier patch and assertion[1] that checking if |
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__GNUC_STDC_INLINE__ or __GNUC_GNU_INLINE__ is defined is sufficient |
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to determine that clang++ suports GNU inlining semantics. |
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Tested with a simple program that builds with __extern_always_inline |
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with the patch and fails compilation without it. |
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#include <stdio.h> |
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#include <sys/cdefs.h> |
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extern void foo_alias (void) __asm ("foo"); |
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__extern_always_inline void |
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foo (void) |
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{ |
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puts ("hi oh world!"); |
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return foo_alias (); |
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} |
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void |
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foo_alias (void) |
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{ |
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puts ("hell oh world"); |
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} |
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int |
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main () |
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{ |
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foo (); |
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} |
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[1] https://sourceware.org/ml/libc-alpha/2012-12/msg00306.html |
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[BZ #17266] |
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* misc/sys/cdefs.h: Define __extern_always_inline for clang |
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4.2 and newer. |
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commit 884ddc5081278f488ef8cd49951f41cfdbb480ce |
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Author: Siddhesh Poyarekar <siddhesh@redhat.com> |
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Date: Tue Sep 16 14:08:48 2014 +0530 |
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Revert to defining __extern_inline only for gcc-4.3+ (BZ #17266) |
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The check for only __GNUC_STDC_INLINE__ and __GNUC_GNU_INLINE__ may |
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not be sufficient since those flags were added during initial support |
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for C99 inlining semantics. There is also a problem with always |
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defining __extern_inline and __extern_always_inline, since it enables |
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inline wrapper functions even when GNU inlining semantics are not |
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guaranteed. This, along with the possibility of such wrappers using |
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redirection (btowc for example) could result in compiler generating an |
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infinitely recusrive call to the function. |
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In fact it was such a recursion that led to this code being written |
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the way it was; see: |
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https://bugzilla.redhat.com/show_bug.cgi?id=186410 |
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The initial change was to fix bugs 14530 and 13741, but they can be |
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resolved by checking if __fortify_function and/or |
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__extern_always_inline are defined, as it has been done in this patch. |
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In addition, I have audited uses of __extern_always_inline to make |
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sure that none of the uses result in compilation errors. |
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There is however a regression in this patch for llvm, since it reverts |
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the llvm expectation that __GNUC_STDC_INLINE__ or __GNUC_GNU_INLINE__ |
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definition imply proper extern inline semantics. |
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2014-09-16 Siddhesh Poyarekar <siddhesh@redhat.com> |
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Jakub Jelinek <jakub@redhat.com> |
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[BZ #17266] |
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* libio/stdio.h: Check definition of __fortify_function |
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instead of __extern_always_inline to include bits/stdio2.h. |
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* math/bits/math-finite.h [__USE_XOPEN || __USE_ISOC99]: Also |
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check if __extern_always_inline is defined. |
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[__USE_MISC || __USE_XOPEN]: Likewise. |
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[__USE_ISOC99] Likewise. |
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* misc/sys/cdefs.h (__fortify_function): Define only if |
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__extern_always_inline is defined. |
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[!__cplusplus || __GNUC_PREREQ (4,3)]: Revert to defining |
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__extern_always_inline and __extern_inline only for g++-4.3 |
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and newer or a compatible gcc. |
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diff --git glibc-2.17-c758a686/libio/stdio.h glibc-2.17-c758a686/libio/stdio.h |
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index d8c0bdb..1f4f837 100644 |
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--- glibc-2.17-c758a686/libio/stdio.h |
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+++ glibc-2.17-c758a686/libio/stdio.h |
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@@ -932,7 +932,7 @@ extern void funlockfile (FILE *__stream) __THROW; |
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#ifdef __USE_EXTERN_INLINES |
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# include <bits/stdio.h> |
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#endif |
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-#if __USE_FORTIFY_LEVEL > 0 && defined __extern_always_inline |
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+#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function |
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# include <bits/stdio2.h> |
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#endif |
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#ifdef __LDBL_COMPAT |
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diff --git glibc-2.17-c758a686/math/bits/math-finite.h glibc-2.17-c758a686/math/bits/math-finite.h |
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index aa755de..0656645 100644 |
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--- glibc-2.17-c758a686/math/bits/math-finite.h |
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+++ glibc-2.17-c758a686/math/bits/math-finite.h |
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@@ -251,7 +251,8 @@ extern long double __REDIRECT_NTH (lgammal_r, (long double, int *), |
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# endif |
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#endif |
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-#if defined __USE_MISC || defined __USE_XOPEN || defined __USE_ISOC99 |
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+#if ((defined __USE_MISC || defined __USE_XOPEN || defined __USE_ISOC99) \ |
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+ && defined __extern_always_inline) |
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/* lgamma. */ |
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__extern_always_inline double __NTH (lgamma (double __d)) |
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{ |
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@@ -284,7 +285,8 @@ __extern_always_inline long double __NTH (lgammal (long double __d)) |
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# endif |
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#endif |
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-#if defined __USE_MISC || defined __USE_XOPEN |
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+#if ((defined __USE_MISC || defined __USE_XOPEN) \ |
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+ && defined __extern_always_inline) |
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/* gamma. */ |
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__extern_always_inline double __NTH (gamma (double __d)) |
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{ |
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@@ -422,7 +424,7 @@ extern long double __REDIRECT_NTH (sqrtl, (long double), __sqrtl_finite); |
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# endif |
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#endif |
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-#ifdef __USE_ISOC99 |
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+#if defined __USE_ISOC99 && defined __extern_always_inline |
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/* tgamma. */ |
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extern double __gamma_r_finite (double, int *); |
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__extern_always_inline double __NTH (tgamma (double __d)) |
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diff --git glibc-2.17-c758a686/misc/sys/cdefs.h glibc-2.17-c758a686/misc/sys/cdefs.h |
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index 04db956..01e81ba 100644 |
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--- glibc-2.17-c758a686/misc/sys/cdefs.h |
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+++ glibc-2.17-c758a686/misc/sys/cdefs.h |
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@@ -131,7 +131,6 @@ |
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/* Fortify support. */ |
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#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1) |
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#define __bos0(ptr) __builtin_object_size (ptr, 0) |
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-#define __fortify_function __extern_always_inline __attribute_artificial__ |
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#if __GNUC_PREREQ (4,3) |
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# define __warndecl(name, msg) \ |
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@@ -319,8 +318,17 @@ |
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#endif |
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/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 |
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- inline semantics, unless -fgnu89-inline is used. */ |
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-#if (!defined __cplusplus || __GNUC_PREREQ (4,3)) && defined __GNUC__ |
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+ inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__ |
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+ or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions |
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+ older than 4.3 may define these macros and still not guarantee GNU inlining |
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+ semantics. |
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+ |
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+ clang++ identifies itself as gcc-4.2, but has support for GNU inlining |
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+ semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and |
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+ __GNUC_GNU_INLINE__ macro definitions. */ |
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+#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \ |
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+ || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \ |
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+ || defined __GNUC_GNU_INLINE__))) |
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# if defined __GNUC_STDC_INLINE__ || defined __cplusplus |
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# define __extern_inline extern __inline __attribute__ ((__gnu_inline__)) |
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# define __extern_always_inline \ |
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@@ -329,13 +337,10 @@ |
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# define __extern_inline extern __inline |
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# define __extern_always_inline extern __always_inline |
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# endif |
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-#elif defined __GNUC__ /* C++ and GCC <4.3. */ |
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-# define __extern_inline extern __inline |
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-# define __extern_always_inline \ |
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- extern __always_inline |
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-#else /* Not GCC. */ |
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-# define __extern_inline /* Ignore */ |
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-# define __extern_always_inline /* Ignore */ |
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+#endif |
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+ |
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+#ifdef __extern_always_inline |
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+# define __fortify_function __extern_always_inline __attribute_artificial__ |
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#endif |
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/* GCC 4.3 and above allow passing all anonymous arguments of an
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