Discussion:
[PATCH 1/3] libc-config: new module
(too old to reply)
Paul Eggert
2017-09-01 23:33:31 UTC
Permalink
Raw Message
* MODULES.html.sh: Add libc-config.
* lib/cdefs.h: New file, copied from the GNU C Library with very
minor changes that can be copied back.
* lib/libc-config.h, modules/libc-config: New files.
---
ChangeLog | 8 +
MODULES.html.sh | 9 +
lib/cdefs.h | 487 ++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/libc-config.h | 184 ++++++++++++++++++++
modules/libc-config | 21 +++
5 files changed, 709 insertions(+)
create mode 100644 lib/cdefs.h
create mode 100644 lib/libc-config.h
create mode 100644 modules/libc-config

diff --git a/ChangeLog b/ChangeLog
index 960c56029..af34bedbb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2017-09-01 Paul Eggert <***@cs.ucla.edu>
+
+ libc-config: new module
+ * MODULES.html.sh: Add libc-config.
+ * lib/cdefs.h: New file, copied from the GNU C Library with very
+ minor changes that can be copied back.
+ * lib/libc-config.h, modules/libc-config: New files.
+
2017-08-31 Paul Eggert <***@cs.ucla.edu>

glob: match dangling symlinks
diff --git a/MODULES.html.sh b/MODULES.html.sh
index 1a258b632..56642d381 100755
--- a/MODULES.html.sh
+++ b/MODULES.html.sh
@@ -2364,6 +2364,15 @@ func_all_modules ()
func_module limits-h
func_end_table

+ element="Support for sharing code with the GNU C Library"
+ func_section_wrap glibc
+ func_wrap H2
+ func_echo "$element"
+
+ func_begin_table
+ func_module libc-config
+ func_end_table
+
element="Support for obsolete systems lacking POSIX:2008"
func_section_wrap posix_sup_obsolete
func_wrap H2
diff --git a/lib/cdefs.h b/lib/cdefs.h
new file mode 100644
index 000000000..d4dd8d041
--- /dev/null
+++ b/lib/cdefs.h
@@ -0,0 +1,487 @@
+/* Copyright (C) 1992-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _SYS_CDEFS_H
+#define _SYS_CDEFS_H 1
+
+/* We are almost always included from features.h. */
+#ifndef _FEATURES_H
+# include <features.h>
+#endif
+
+/* The GNU libc does not support any K&R compilers or the traditional mode
+ of ISO C compilers anymore. Check for some of the combinations not
+ anymore supported. */
+#if defined __GNUC__ && !defined __STDC__
+# error "You need a ISO C conforming compiler to use the glibc headers"
+#endif
+
+/* Some user header file might have defined this before. */
+#undef __P
+#undef __PMT
+
+#ifdef __GNUC__
+
+/* All functions, except those with callbacks or those that
+ synchronize memory, are leaf functions. */
+# if __GNUC_PREREQ (4, 6) && !defined _LIBC
+# define __LEAF , __leaf__
+# define __LEAF_ATTR __attribute__ ((__leaf__))
+# else
+# define __LEAF
+# define __LEAF_ATTR
+# endif
+
+/* GCC can always grok prototypes. For C++ programs we add throw()
+ to help it optimize the function calls. But this works only with
+ gcc 2.8.x and egcs. For gcc 3.2 and up we even mark C functions
+ as non-throwing using a function attribute since programs can use
+ the -fexceptions options for C code as well. */
+# if !defined __cplusplus && __GNUC_PREREQ (3, 3)
+# define __THROW __attribute__ ((__nothrow__ __LEAF))
+# define __THROWNL __attribute__ ((__nothrow__))
+# define __NTH(fct) __attribute__ ((__nothrow__ __LEAF)) fct
+# define __NTHNL(fct) __attribute__ ((__nothrow__)) fct
+# else
+# if defined __cplusplus && __GNUC_PREREQ (2,8)
+# define __THROW throw ()
+# define __THROWNL throw ()
+# define __NTH(fct) __LEAF_ATTR fct throw ()
+# define __NTHNL(fct) fct throw ()
+# else
+# define __THROW
+# define __THROWNL
+# define __NTH(fct) fct
+# define __NTHNL(fct) fct
+# endif
+# endif
+
+#else /* Not GCC. */
+
+# define __inline /* No inline functions. */
+
+# define __THROW
+# define __THROWNL
+# define __NTH(fct) fct
+
+#endif /* GCC. */
+
+/* Compilers that are not clang may object to
+ #if defined __clang__ && __has_extension(...)
+ even though they do not need to evaluate the right-hand side of the &&. */
+#if defined __clang__ && defined __has_extension
+# define __glibc_clang_has_extension(ext) __has_extension (ext)
+#else
+# define __glibc_clang_has_extension(ext) 0
+#endif
+
+/* These two macros are not used in glibc anymore. They are kept here
+ only because some other projects expect the macros to be defined. */
+#define __P(args) args
+#define __PMT(args) args
+
+/* For these things, GCC behaves the ANSI way normally,
+ and the non-ANSI way under -traditional. */
+
+#define __CONCAT(x,y) x ## y
+#define __STRING(x) #x
+
+/* This is not a typedef so `const __ptr_t' does the right thing. */
+#define __ptr_t void *
+
+
+/* C++ needs to know that types and declarations are C, not C++. */
+#ifdef __cplusplus
+# define __BEGIN_DECLS extern "C" {
+# define __END_DECLS }
+#else
+# define __BEGIN_DECLS
+# define __END_DECLS
+#endif
+
+
+/* Fortify support. */
+#define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
+#define __bos0(ptr) __builtin_object_size (ptr, 0)
+
+#if __GNUC_PREREQ (4,3)
+# define __warndecl(name, msg) \
+ extern void name (void) __attribute__((__warning__ (msg)))
+# define __warnattr(msg) __attribute__((__warning__ (msg)))
+# define __errordecl(name, msg) \
+ extern void name (void) __attribute__((__error__ (msg)))
+#else
+# define __warndecl(name, msg) extern void name (void)
+# define __warnattr(msg)
+# define __errordecl(name, msg) extern void name (void)
+#endif
+
+/* Support for flexible arrays.
+ Headers that should use flexible arrays only if they're "real"
+ (e.g. only if they won't affect sizeof()) should test
+ #if __glibc_c99_flexarr_available. */
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+# define __flexarr []
+# define __glibc_c99_flexarr_available 1
+#elif __GNUC_PREREQ (2,97)
+/* GCC 2.97 supports C99 flexible array members as an extension,
+ even when in C89 mode or compiling C++ (any version). */
+# define __flexarr []
+# define __glibc_c99_flexarr_available 1
+#elif defined __GNUC__
+/* Pre-2.97 GCC did not support C99 flexible arrays but did have
+ an equivalent extension with slightly different notation. */
+# define __flexarr [0]
+# define __glibc_c99_flexarr_available 1
+#else
+/* Some other non-C99 compiler. Approximate with [1]. */
+# define __flexarr [1]
+# define __glibc_c99_flexarr_available 0
+#endif
+
+
+/* __asm__ ("xyz") is used throughout the headers to rename functions
+ at the assembly language level. This is wrapped by the __REDIRECT
+ macro, in order to support compilers that can do this some other
+ way. When compilers don't support asm-names at all, we have to do
+ preprocessor tricks instead (which don't have exactly the right
+ semantics, but it's the best we can do).
+
+ Example:
+ int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
+
+#if defined __GNUC__ && __GNUC__ >= 2
+
+# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
+# ifdef __cplusplus
+# define __REDIRECT_NTH(name, proto, alias) \
+ name proto __THROW __asm__ (__ASMNAME (#alias))
+# define __REDIRECT_NTHNL(name, proto, alias) \
+ name proto __THROWNL __asm__ (__ASMNAME (#alias))
+# else
+# define __REDIRECT_NTH(name, proto, alias) \
+ name proto __asm__ (__ASMNAME (#alias)) __THROW
+# define __REDIRECT_NTHNL(name, proto, alias) \
+ name proto __asm__ (__ASMNAME (#alias)) __THROWNL
+# endif
+# define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname)
+# define __ASMNAME2(prefix, cname) __STRING (prefix) cname
+
+/*
+#elif __SOME_OTHER_COMPILER__
+
+# define __REDIRECT(name, proto, alias) name proto; \
+ _Pragma("let " #name " = " #alias)
+*/
+#endif
+
+/* GCC has various useful declarations that can be made with the
+ `__attribute__' syntax. All of the ways we use this do fine if
+ they are omitted for compilers that don't understand it. */
+#if !defined __GNUC__ || __GNUC__ < 2
+# define __attribute__(xyz) /* Ignore */
+#endif
+
+/* At some point during the gcc 2.96 development the `malloc' attribute
+ for functions was introduced. We don't want to use it unconditionally
+ (although this would be possible) since it generates warnings. */
+#if __GNUC_PREREQ (2,96)
+# define __attribute_malloc__ __attribute__ ((__malloc__))
+#else
+# define __attribute_malloc__ /* Ignore */
+#endif
+
+/* Tell the compiler which arguments to an allocation function
+ indicate the size of the allocation. */
+#if __GNUC_PREREQ (4, 3)
+# define __attribute_alloc_size__(params) \
+ __attribute__ ((__alloc_size__ params))
+#else
+# define __attribute_alloc_size__(params) /* Ignore. */
+#endif
+
+/* At some point during the gcc 2.96 development the `pure' attribute
+ for functions was introduced. We don't want to use it unconditionally
+ (although this would be possible) since it generates warnings. */
+#if __GNUC_PREREQ (2,96)
+# define __attribute_pure__ __attribute__ ((__pure__))
+#else
+# define __attribute_pure__ /* Ignore */
+#endif
+
+/* This declaration tells the compiler that the value is constant. */
+#if __GNUC_PREREQ (2,5)
+# define __attribute_const__ __attribute__ ((__const__))
+#else
+# define __attribute_const__ /* Ignore */
+#endif
+
+/* At some point during the gcc 3.1 development the `used' attribute
+ for functions was introduced. We don't want to use it unconditionally
+ (although this would be possible) since it generates warnings. */
+#if __GNUC_PREREQ (3,1)
+# define __attribute_used__ __attribute__ ((__used__))
+# define __attribute_noinline__ __attribute__ ((__noinline__))
+#else
+# define __attribute_used__ __attribute__ ((__unused__))
+# define __attribute_noinline__ /* Ignore */
+#endif
+
+/* Since version 3.2, gcc allows marking deprecated functions. */
+#if __GNUC_PREREQ (3,2)
+# define __attribute_deprecated__ __attribute__ ((__deprecated__))
+#else
+# define __attribute_deprecated__ /* Ignore */
+#endif
+
+/* Since version 4.5, gcc also allows one to specify the message printed
+ when a deprecated function is used. clang claims to be gcc 4.2, but
+ may also support this feature. */
+#if __GNUC_PREREQ (4,5) || \
+ __glibc_clang_has_extension (__attribute_deprecated_with_message__)
+# define __attribute_deprecated_msg__(msg) \
+ __attribute__ ((__deprecated__ (msg)))
+#else
+# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
+#endif
+
+/* At some point during the gcc 2.8 development the `format_arg' attribute
+ for functions was introduced. We don't want to use it unconditionally
+ (although this would be possible) since it generates warnings.
+ If several `format_arg' attributes are given for the same function, in
+ gcc-3.0 and older, all but the last one are ignored. In newer gccs,
+ all designated arguments are considered. */
+#if __GNUC_PREREQ (2,8)
+# define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x)))
+#else
+# define __attribute_format_arg__(x) /* Ignore */
+#endif
+
+/* At some point during the gcc 2.97 development the `strfmon' format
+ attribute for functions was introduced. We don't want to use it
+ unconditionally (although this would be possible) since it
+ generates warnings. */
+#if __GNUC_PREREQ (2,97)
+# define __attribute_format_strfmon__(a,b) \
+ __attribute__ ((__format__ (__strfmon__, a, b)))
+#else
+# define __attribute_format_strfmon__(a,b) /* Ignore */
+#endif
+
+/* The nonull function attribute allows to mark pointer parameters which
+ must not be NULL. */
+#if __GNUC_PREREQ (3,3)
+# define __nonnull(params) __attribute__ ((__nonnull__ params))
+#else
+# define __nonnull(params)
+#endif
+
+/* If fortification mode, we warn about unused results of certain
+ function calls which can lead to problems. */
+#if __GNUC_PREREQ (3,4)
+# define __attribute_warn_unused_result__ \
+ __attribute__ ((__warn_unused_result__))
+# if __USE_FORTIFY_LEVEL > 0
+# define __wur __attribute_warn_unused_result__
+# endif
+#else
+# define __attribute_warn_unused_result__ /* empty */
+#endif
+#ifndef __wur
+# define __wur /* Ignore */
+#endif
+
+/* Forces a function to be always inlined. */
+#if __GNUC_PREREQ (3,2)
+/* The Linux kernel defines __always_inline in stddef.h (283d7573), and
+ it conflicts with this definition. Therefore undefine it first to
+ allow either header to be included first. */
+# undef __always_inline
+# define __always_inline __inline __attribute__ ((__always_inline__))
+#else
+# undef __always_inline
+# define __always_inline __inline
+#endif
+
+/* Associate error messages with the source location of the call site rather
+ than with the source location inside the function. */
+#if __GNUC_PREREQ (4,3)
+# define __attribute_artificial__ __attribute__ ((__artificial__))
+#else
+# define __attribute_artificial__ /* Ignore */
+#endif
+
+/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
+ inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
+ or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
+ older than 4.3 may define these macros and still not guarantee GNU inlining
+ semantics.
+
+ clang++ identifies itself as gcc-4.2, but has support for GNU inlining
+ semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
+ __GNUC_GNU_INLINE__ macro definitions. */
+#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
+ || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
+ || defined __GNUC_GNU_INLINE__)))
+# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
+# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
+# define __extern_always_inline \
+ extern __always_inline __attribute__ ((__gnu_inline__))
+# else
+# define __extern_inline extern __inline
+# define __extern_always_inline extern __always_inline
+# endif
+#endif
+
+#ifdef __extern_always_inline
+# define __fortify_function __extern_always_inline __attribute_artificial__
+#endif
+
+/* GCC 4.3 and above allow passing all anonymous arguments of an
+ __extern_always_inline function to some other vararg function. */
+#if __GNUC_PREREQ (4,3)
+# define __va_arg_pack() __builtin_va_arg_pack ()
+# define __va_arg_pack_len() __builtin_va_arg_pack_len ()
+#endif
+
+/* It is possible to compile containing GCC extensions even if GCC is
+ run in pedantic mode if the uses are carefully marked using the
+ `__extension__' keyword. But this is not generally available before
+ version 2.8. */
+#if !__GNUC_PREREQ (2,8)
+# define __extension__ /* Ignore */
+#endif
+
+/* __restrict is known in EGCS 1.2 and above. */
+#if !__GNUC_PREREQ (2,92)
+# define __restrict /* Ignore */
+#endif
+
+/* ISO C99 also allows to declare arrays as non-overlapping. The syntax is
+ array_name[restrict]
+ GCC 3.1 supports this. */
+#if __GNUC_PREREQ (3,1) && !defined __GNUG__
+# define __restrict_arr __restrict
+#else
+# ifdef __GNUC__
+# define __restrict_arr /* Not supported in old GCC. */
+# else
+# if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+# define __restrict_arr restrict
+# else
+/* Some other non-C99 compiler. */
+# define __restrict_arr /* Not supported. */
+# endif
+# endif
+#endif
+
+#if __GNUC__ >= 3
+# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
+# define __glibc_likely(cond) __builtin_expect ((cond), 1)
+#else
+# define __glibc_unlikely(cond) (cond)
+# define __glibc_likely(cond) (cond)
+#endif
+
+#if (!defined _Noreturn \
+ && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
+ && !__GNUC_PREREQ (4,7))
+# if __GNUC_PREREQ (2,8)
+# define _Noreturn __attribute__ ((__noreturn__))
+# else
+# define _Noreturn
+# endif
+#endif
+
+#if (!defined _Static_assert && !defined __cplusplus \
+ && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
+ && (!__GNUC_PREREQ (4, 6) || defined __STRICT_ANSI__))
+# define _Static_assert(expr, diagnostic) \
+ extern int (*__Static_assert_function (void)) \
+ [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
+#endif
+
+/* The #ifndef lets Gnulib avoid including these on non-glibc
+ platforms, where the includes typically do not exist. */
+#ifndef __WORDSIZE
+# include <bits/wordsize.h>
+# include <bits/long-double.h>
+#endif
+
+#if defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
+# define __LDBL_COMPAT 1
+# ifdef __REDIRECT
+# define __LDBL_REDIR1(name, proto, alias) __REDIRECT (name, proto, alias)
+# define __LDBL_REDIR(name, proto) \
+ __LDBL_REDIR1 (name, proto, __nldbl_##name)
+# define __LDBL_REDIR1_NTH(name, proto, alias) __REDIRECT_NTH (name, proto, alias)
+# define __LDBL_REDIR_NTH(name, proto) \
+ __LDBL_REDIR1_NTH (name, proto, __nldbl_##name)
+# define __LDBL_REDIR1_DECL(name, alias) \
+ extern __typeof (name) name __asm (__ASMNAME (#alias));
+# define __LDBL_REDIR_DECL(name) \
+ extern __typeof (name) name __asm (__ASMNAME ("__nldbl_" #name));
+# define __REDIRECT_LDBL(name, proto, alias) \
+ __LDBL_REDIR1 (name, proto, __nldbl_##alias)
+# define __REDIRECT_NTH_LDBL(name, proto, alias) \
+ __LDBL_REDIR1_NTH (name, proto, __nldbl_##alias)
+# endif
+#endif
+#if !defined __LDBL_COMPAT || !defined __REDIRECT
+# define __LDBL_REDIR1(name, proto, alias) name proto
+# define __LDBL_REDIR(name, proto) name proto
+# define __LDBL_REDIR1_NTH(name, proto, alias) name proto __THROW
+# define __LDBL_REDIR_NTH(name, proto) name proto __THROW
+# define __LDBL_REDIR_DECL(name)
+# ifdef __REDIRECT
+# define __REDIRECT_LDBL(name, proto, alias) __REDIRECT (name, proto, alias)
+# define __REDIRECT_NTH_LDBL(name, proto, alias) \
+ __REDIRECT_NTH (name, proto, alias)
+# endif
+#endif
+
+/* __glibc_macro_warning (MESSAGE) issues warning MESSAGE. This is
+ intended for use in preprocessor macros.
+
+ Note: MESSAGE must be a _single_ string; concatenation of string
+ literals is not supported. */
+#if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
+# define __glibc_macro_warning1(message) _Pragma (#message)
+# define __glibc_macro_warning(message) \
+ __glibc_macro_warning1 (GCC warning message)
+#else
+# define __glibc_macro_warning(msg)
+#endif
+
+/* Generic selection (ISO C11) is a C-only feature, available in GCC
+ since version 4.9. Previous versions do not provide generic
+ selection, even though they might set __STDC_VERSION__ to 201112L,
+ when in -std=c11 mode. Thus, we must check for !defined __GNUC__
+ when testing __STDC_VERSION__ for generic selection support.
+ On the other hand, Clang also defines __GNUC__, so a clang-specific
+ check is required to enable the use of generic selection. */
+#if !defined __cplusplus \
+ && (__GNUC_PREREQ (4, 9) \
+ || __glibc_clang_has_extension (c_generic_selections) \
+ || (!defined __GNUC__ && defined __STDC_VERSION__ \
+ && __STDC_VERSION__ >= 201112L))
+# define __HAVE_GENERIC_SELECTION 1
+#else
+# define __HAVE_GENERIC_SELECTION 0
+#endif
+
+#endif /* sys/cdefs.h */
diff --git a/lib/libc-config.h b/lib/libc-config.h
new file mode 100644
index 000000000..2ebb8756e
--- /dev/null
+++ b/lib/libc-config.h
@@ -0,0 +1,184 @@
+/* System definitions for code taken from the GNU C Library
+
+ Copyright 2017 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this program; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+/* Written by Paul Eggert. */
+
+/* This is intended to be a good-enough substitute for glibc system
+ macros like those defined in <sys/cdefs.h>, so that Gnulib code
+ shared with glibc can do this as the first #include:
+
+ #ifndef _LIBC
+ # include <libc-config.h>
+ #endif
+
+ When compiled as part of glibc this is a no-op; when compiled as
+ part of Gnulib this includes Gnulib's <config.h> and defines macros
+ that glibc library code would normally assume. */
+
+#include <config.h>
+
+/* On glibc this includes <features.h> and <sys/cdefs.h> and #defines
+ _FEATURES_H, __WORDSIZE, and __set_errno. On other platforms this
+ is harmless. */
+#include <errno.h>
+
+/* From glibc <errno.h>. */
+#ifndef __set_errno
+# define __set_errno(val) (errno = (val))
+#endif
+
+/* From glibc <features.h>. */
+
+#ifndef __GNUC_PREREQ
+# if defined __GNUC__ && defined __GNUC_MINOR__
+# define __GNUC_PREREQ(maj, min) ((maj) < __GNUC__ + ((min) <= __GNUC_MINOR))
+# else
+# define __GNUC_PREREQ(maj, min) 0
+# endif
+#endif
+
+#ifndef __glibc_clang_prereq
+# if defined __clang_major__ && defined __clang_minor__
+# define __glibc_clang_prereq(maj, min) \
+ ((maj) < __clang_major__ + ((min) <= __clang_minor__))
+# else
+# define __glibc_clang_prereq(maj, min) 0
+# endif
+#endif
+
+
+/* Prepare to include <cdefs.h>, which is our copy of glibc
+ <sys/cdefs.h>. */
+
+/* Define _FEATURES_H so that <cdefs.h> does not include <features.h>. */
+#ifndef _FEATURES_H
+# define _FEATURES_H 1
+#endif
+/* Define __WORDSIZE so that <cdefs.h> does not attempt to include
+ nonexistent files. Make it a syntax error, since Gnulib does not
+ use __WORDSIZE now, and if Gnulib uses it later the syntax error
+ will let us know that __WORDSIZE needs configuring. */
+#ifndef __WORDSIZE
+# define __WORDSIZE %%%
+#endif
+/* Undef the macros unconditionally defined by our copy of glibc
+ <sys/cdefs.h>, so that they do not clash with any system-defined
+ versions. */
+#undef _SYS_CDEFS_H
+#undef __ASMNAME
+#undef __ASMNAME2
+#undef __BEGIN_DECLS
+#undef __CONCAT
+#undef __END_DECLS
+#undef __HAVE_GENERIC_SELECTION
+#undef __LDBL_COMPAT
+#undef __LDBL_REDIR
+#undef __LDBL_REDIR1
+#undef __LDBL_REDIR1_DECL
+#undef __LDBL_REDIR1_NTH
+#undef __LDBL_REDIR_DECL
+#undef __LDBL_REDIR_NTH
+#undef __LEAF
+#undef __LEAF_ATTR
+#undef __NTH
+#undef __NTHNL
+#undef __P
+#undef __PMT
+#undef __REDIRECT
+#undef __REDIRECT_LDBL
+#undef __REDIRECT_NTH
+#undef __REDIRECT_NTHNL
+#undef __REDIRECT_NTH_LDBL
+#undef __STRING
+#undef __THROW
+#undef __THROWNL
+#undef __always_inline
+#undef __attribute__
+#undef __attribute_alloc_size__
+#undef __attribute_artificial__
+#undef __attribute_const__
+#undef __attribute_deprecated__
+#undef __attribute_deprecated_msg__
+#undef __attribute_format_arg__
+#undef __attribute_format_strfmon__
+#undef __attribute_malloc__
+#undef __attribute_noinline__
+#undef __attribute_pure__
+#undef __attribute_used__
+#undef __attribute_warn_unused_result__
+#undef __bos
+#undef __bos0
+#undef __errordecl
+#undef __extension__
+#undef __extern_always_inline
+#undef __extern_inline
+#undef __flexarr
+#undef __fortify_function
+#undef __glibc_c99_flexarr_available
+#undef __glibc_clang_has_extension
+#undef __glibc_likely
+#undef __glibc_macro_warning
+#undef __glibc_macro_warning1
+#undef __glibc_unlikely
+#undef __inline
+#undef __nonnull
+#undef __ptr_t
+#undef __restrict
+#undef __restrict_arr
+#undef __va_arg_pack
+#undef __va_arg_pack_len
+#undef __warnattr
+#undef __warndecl
+
+/* Include our copy of glibc <sys/cdefs.h>. */
+#include <cdefs.h>
+
+/* <cdefs.h> __inline is too pessimistic for non-GCC. */
+#undef __inline
+#ifndef __GNUC__
+# if 199901 <= __STDC_VERSION__
+# define __inline inline
+# else
+# define __inline
+# endif
+#endif
+
+/* <cdefs.h> __restrict is too pessimistic for non-GCC. GCC 2.95 and
+ later have "__restrict", and C99 compilers have "restrict". */
+#undef __restrict
+#if !__GNUC_PREREQ (2, 95)
+# if 199901L <= __STDC_VERSION__
+# define __restrict restrict
+# else
+# define __restrict
+# endif
+#endif
+
+
+/* A substitute for glibc <libc-symbols.h>, good enough for Gnulib. */
+#define attribute_hidden
+#define libc_hidden_proto(name, attrs...)
+#define libc_hidden_def(name)
+#define libc_hidden_weak(name)
+#define libc_hidden_ver(local, name)
+#define strong_alias(name, aliasname)
+#define weak_alias(name, aliasname)
+
+/* A substitute for glibc <shlib-compat.h>, good enough for Gnulib. */
+#define SHLIB_COMPAT(lib, introduced, obsoleted) 0
+#define versioned_symbol(lib, local, symbol, version)
diff --git a/modules/libc-config b/modules/libc-config
new file mode 100644
index 000000000..8df46fec9
--- /dev/null
+++ b/modules/libc-config
@@ -0,0 +1,21 @@
+Description:
+System definitions for code taken from the GNU C Library
+
+Files:
+lib/cdefs.h
+lib/libc-config.h
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+
+Include:
+<libc-config.h>
+
+License:
+LGPLv2+
+
+Maintainer:
+all
--
2.13.5
Paul Eggert
2017-09-01 23:33:32 UTC
Permalink
Raw Message
* lib/scratch_buffer.h, lib/scratch_buffer_grow.c:
* lib/scratch_buffer_grow_preserve.c:
* lib/scratch_buffer_set_array_size.c:
New files, copied from glibc with very minor changes that can be
copied back.
* modules/scratch_buffer: New file.
---
ChangeLog | 8 +++
lib/scratch_buffer.h | 135 ++++++++++++++++++++++++++++++++++++
lib/scratch_buffer_grow.c | 56 +++++++++++++++
lib/scratch_buffer_grow_preserve.c | 67 ++++++++++++++++++
lib/scratch_buffer_set_array_size.c | 64 +++++++++++++++++
modules/scratch_buffer | 32 +++++++++
6 files changed, 362 insertions(+)
create mode 100644 lib/scratch_buffer.h
create mode 100644 lib/scratch_buffer_grow.c
create mode 100644 lib/scratch_buffer_grow_preserve.c
create mode 100644 lib/scratch_buffer_set_array_size.c
create mode 100644 modules/scratch_buffer

diff --git a/ChangeLog b/ChangeLog
index af34bedbb..078d5243c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
2017-09-01 Paul Eggert <***@cs.ucla.edu>

+ scratch_buffer: new module
+ * lib/scratch_buffer.h, lib/scratch_buffer_grow.c:
+ * lib/scratch_buffer_grow_preserve.c:
+ * lib/scratch_buffer_set_array_size.c:
+ New files, copied from glibc with very minor changes that can be
+ copied back.
+ * modules/scratch_buffer: New file.
+
libc-config: new module
* MODULES.html.sh: Add libc-config.
* lib/cdefs.h: New file, copied from the GNU C Library with very
diff --git a/lib/scratch_buffer.h b/lib/scratch_buffer.h
new file mode 100644
index 000000000..bb04662eb
--- /dev/null
+++ b/lib/scratch_buffer.h
@@ -0,0 +1,135 @@
+/* Variable-sized buffer with on-stack default allocation.
+ Copyright (C) 2015-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _SCRATCH_BUFFER_H
+#define _SCRATCH_BUFFER_H
+
+/* Scratch buffers with a default stack allocation and fallback to
+ heap allocation. It is expected that this function is used in this
+ way:
+
+ struct scratch_buffer tmpbuf;
+ scratch_buffer_init (&tmpbuf);
+
+ while (!function_that_uses_buffer (tmpbuf.data, tmpbuf.length))
+ if (!scratch_buffer_grow (&tmpbuf))
+ return -1;
+
+ scratch_buffer_free (&tmpbuf);
+ return 0;
+
+ The allocation functions (scratch_buffer_grow,
+ scratch_buffer_grow_preserve, scratch_buffer_set_array_size) make
+ sure that the heap allocation, if any, is freed, so that the code
+ above does not have a memory leak. The buffer still remains in a
+ state that can be deallocated using scratch_buffer_free, so a loop
+ like this is valid as well:
+
+ struct scratch_buffer tmpbuf;
+ scratch_buffer_init (&tmpbuf);
+
+ while (!function_that_uses_buffer (tmpbuf.data, tmpbuf.length))
+ if (!scratch_buffer_grow (&tmpbuf))
+ break;
+
+ scratch_buffer_free (&tmpbuf);
+
+ scratch_buffer_grow and scratch_buffer_grow_preserve are guaranteed
+ to grow the buffer by at least 512 bytes. This means that when
+ using the scratch buffer as a backing store for a non-character
+ array whose element size, in bytes, is 512 or smaller, the scratch
+ buffer only has to grow once to make room for at least one more
+ element.
+*/
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+/* Scratch buffer. Must be initialized with scratch_buffer_init
+ before its use. */
+struct scratch_buffer {
+ void *data; /* Pointer to the beginning of the scratch area. */
+ size_t length; /* Allocated space at the data pointer, in bytes. */
+ max_align_t __space[(1023 + sizeof (max_align_t)) / sizeof (max_align_t)];
+};
+
+/* Initializes *BUFFER so that BUFFER->data points to BUFFER->__space
+ and BUFFER->length reflects the available space. */
+static inline void
+scratch_buffer_init (struct scratch_buffer *buffer)
+{
+ buffer->data = buffer->__space;
+ buffer->length = sizeof (buffer->__space);
+}
+
+/* Deallocates *BUFFER (if it was heap-allocated). */
+static inline void
+scratch_buffer_free (struct scratch_buffer *buffer)
+{
+ if (buffer->data != buffer->__space)
+ free (buffer->data);
+}
+
+/* Grow *BUFFER by some arbitrary amount. The buffer contents is NOT
+ preserved. Return true on success, false on allocation failure (in
+ which case the old buffer is freed). On success, the new buffer is
+ larger than the previous size. On failure, *BUFFER is deallocated,
+ but remains in a free-able state, and errno is set. */
+bool __libc_scratch_buffer_grow (struct scratch_buffer *buffer);
+libc_hidden_proto (__libc_scratch_buffer_grow)
+
+/* Alias for __libc_scratch_buffer_grow. */
+static __always_inline bool
+scratch_buffer_grow (struct scratch_buffer *buffer)
+{
+ return __glibc_likely (__libc_scratch_buffer_grow (buffer));
+}
+
+/* Like __libc_scratch_buffer_grow, but preserve the old buffer
+ contents on success, as a prefix of the new buffer. */
+bool __libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer);
+libc_hidden_proto (__libc_scratch_buffer_grow_preserve)
+
+/* Alias for __libc_scratch_buffer_grow_preserve. */
+static __always_inline bool
+scratch_buffer_grow_preserve (struct scratch_buffer *buffer)
+{
+ return __glibc_likely (__libc_scratch_buffer_grow_preserve (buffer));
+}
+
+/* Grow *BUFFER so that it can store at least NELEM elements of SIZE
+ bytes. The buffer contents are NOT preserved. Both NELEM and SIZE
+ can be zero. Return true on success, false on allocation failure
+ (in which case the old buffer is freed, but *BUFFER remains in a
+ free-able state, and errno is set). It is unspecified whether this
+ function can reduce the array size. */
+bool __libc_scratch_buffer_set_array_size (struct scratch_buffer *buffer,
+ size_t nelem, size_t size);
+libc_hidden_proto (__libc_scratch_buffer_set_array_size)
+
+/* Alias for __libc_scratch_set_array_size. */
+static __always_inline bool
+scratch_buffer_set_array_size (struct scratch_buffer *buffer,
+ size_t nelem, size_t size)
+{
+ return __glibc_likely (__libc_scratch_buffer_set_array_size
+ (buffer, nelem, size));
+}
+
+#endif /* _SCRATCH_BUFFER_H */
diff --git a/lib/scratch_buffer_grow.c b/lib/scratch_buffer_grow.c
new file mode 100644
index 000000000..d2df02865
--- /dev/null
+++ b/lib/scratch_buffer_grow.c
@@ -0,0 +1,56 @@
+/* Variable-sized buffer with on-stack default allocation.
+ Copyright (C) 2015-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _LIBC
+# include <libc-config.h>
+#endif
+
+#include <scratch_buffer.h>
+#include <errno.h>
+
+bool
+__libc_scratch_buffer_grow (struct scratch_buffer *buffer)
+{
+ void *new_ptr;
+ size_t new_length = buffer->length * 2;
+
+ /* Discard old buffer. */
+ scratch_buffer_free (buffer);
+
+ /* Check for overflow. */
+ if (__glibc_likely (new_length >= buffer->length))
+ new_ptr = malloc (new_length);
+ else
+ {
+ __set_errno (ENOMEM);
+ new_ptr = NULL;
+ }
+
+ if (__glibc_unlikely (new_ptr == NULL))
+ {
+ /* Buffer must remain valid to free. */
+ scratch_buffer_init (buffer);
+ return false;
+ }
+
+ /* Install new heap-based buffer. */
+ buffer->data = new_ptr;
+ buffer->length = new_length;
+ return true;
+}
+libc_hidden_def (__libc_scratch_buffer_grow)
diff --git a/lib/scratch_buffer_grow_preserve.c b/lib/scratch_buffer_grow_preserve.c
new file mode 100644
index 000000000..926861531
--- /dev/null
+++ b/lib/scratch_buffer_grow_preserve.c
@@ -0,0 +1,67 @@
+/* Variable-sized buffer with on-stack default allocation.
+ Copyright (C) 2015-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _LIBC
+# include <libc-config.h>
+#endif
+
+#include <scratch_buffer.h>
+#include <errno.h>
+#include <string.h>
+
+bool
+__libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer)
+{
+ size_t new_length = 2 * buffer->length;
+ void *new_ptr;
+
+ if (buffer->data == buffer->__space)
+ {
+ /* Move buffer to the heap. No overflow is possible because
+ buffer->length describes a small buffer on the stack. */
+ new_ptr = malloc (new_length);
+ if (new_ptr == NULL)
+ return false;
+ memcpy (new_ptr, buffer->__space, buffer->length);
+ }
+ else
+ {
+ /* Buffer was already on the heap. Check for overflow. */
+ if (__glibc_likely (new_length >= buffer->length))
+ new_ptr = realloc (buffer->data, new_length);
+ else
+ {
+ __set_errno (ENOMEM);
+ new_ptr = NULL;
+ }
+
+ if (__glibc_unlikely (new_ptr == NULL))
+ {
+ /* Deallocate, but buffer must remain valid to free. */
+ free (buffer->data);
+ scratch_buffer_init (buffer);
+ return false;
+ }
+ }
+
+ /* Install new heap-based buffer. */
+ buffer->data = new_ptr;
+ buffer->length = new_length;
+ return true;
+}
+libc_hidden_def (__libc_scratch_buffer_grow_preserve)
diff --git a/lib/scratch_buffer_set_array_size.c b/lib/scratch_buffer_set_array_size.c
new file mode 100644
index 000000000..6fcc11534
--- /dev/null
+++ b/lib/scratch_buffer_set_array_size.c
@@ -0,0 +1,64 @@
+/* Variable-sized buffer with on-stack default allocation.
+ Copyright (C) 2015-2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _LIBC
+# include <libc-config.h>
+#endif
+
+#include <scratch_buffer.h>
+#include <errno.h>
+#include <limits.h>
+
+bool
+__libc_scratch_buffer_set_array_size (struct scratch_buffer *buffer,
+ size_t nelem, size_t size)
+{
+ size_t new_length = nelem * size;
+
+ /* Avoid overflow check if both values are small. */
+ if ((nelem | size) >> (sizeof (size_t) * CHAR_BIT / 2) != 0
+ && nelem != 0 && size != new_length / nelem)
+ {
+ /* Overflow. Discard the old buffer, but it must remain valid
+ to free. */
+ scratch_buffer_free (buffer);
+ scratch_buffer_init (buffer);
+ __set_errno (ENOMEM);
+ return false;
+ }
+
+ if (new_length <= buffer->length)
+ return true;
+
+ /* Discard old buffer. */
+ scratch_buffer_free (buffer);
+
+ char *new_ptr = malloc (new_length);
+ if (new_ptr == NULL)
+ {
+ /* Buffer must remain valid to free. */
+ scratch_buffer_init (buffer);
+ return false;
+ }
+
+ /* Install new heap-based buffer. */
+ buffer->data = new_ptr;
+ buffer->length = new_length;
+ return true;
+}
+libc_hidden_def (__libc_scratch_buffer_set_array_size)
diff --git a/modules/scratch_buffer b/modules/scratch_buffer
new file mode 100644
index 000000000..7502d707d
--- /dev/null
+++ b/modules/scratch_buffer
@@ -0,0 +1,32 @@
+Description:
+Variable-sized buffer with on-stack default allocation.
+
+Files:
+lib/scratch_buffer.h
+lib/scratch_buffer_grow.c
+lib/scratch_buffer_grow_preserve.c
+lib/scratch_buffer_set_array_size.c
+
+Depends-on:
+libc-config
+stdbool
+stddef
+
+configure.ac:
+AC_CHECK_FUNCS_ONCE([__libc_scratch_buffer_grow])
+if test "$ac_cv_func___libc_scratch_buffer_grow" != yes; then
+ AC_LIBOBJ([scratch_buffer_grow])
+ AC_LIBOBJ([scratch_buffer_grow_preserve])
+ AC_LIBOBJ([scratch_buffer_set_array_size])
+fi
+
+Makefile.am:
+
+Include:
+<scratch_buffer.h>
+
+License:
+LGPLv2+
+
+Maintainer:
+all, glibc
--
2.13.5
Florian Weimer
2017-09-02 07:31:44 UTC
Permalink
Raw Message
Post by Paul Eggert
+AC_CHECK_FUNCS_ONCE([__libc_scratch_buffer_grow])
This configure test is invalid because __libc_scratch_buffer_grow is a
GLIBC_PRIVATE symbol not part of the ABI.

You really need to rename those __libc_* functions because they are in
the internal glibc namespace.

Furthermore, struct scratch_buffer depends on a GNU C extension:
assignment to an object changes its dynamic type. It is not standard C.
Standard C only allows one way to allocate untyped memory, and that is
malloc.

Thanks,
Florian
Paul Eggert
2017-09-02 09:11:27 UTC
Permalink
Raw Message
Post by Florian Weimer
This configure test is invalid because __libc_scratch_buffer_grow is a
GLIBC_PRIVATE symbol not part of the ABI.
You really need to rename those __libc_* functions because they are in
the internal glibc namespace.
Done by installing the first attached patch into Gnulib. This doesn't need any
change to glibc: though it renames the Gnulib files that correspond to glibc, it
does not change their contents.

It is an annoyance, though, that Gnulib-using apps now need another copy of the
functions in question. How about publicizing that part of the glibc API, to
avoid the duplication?

While looking into the above problem, I noticed a portability issue with
platforms lacking getpwnam_r. Fixed in Gnulib in the 2nd attached patch.

And while looking into *that* problem, I noticed that the code needlessly saves
and restores errno on platforms that have getpwnam_r. Fixed in Gnulib in the 3rd
attached patch.

The last two patches should be ported back to glibc.
Post by Florian Weimer
assignment to an object changes its dynamic type. It is not standard C.
Standard C only allows one way to allocate untyped memory, and that is
malloc.
That should not be a problem, as Gnulib code regularly breaks those standard-C
rules when it comes to memory allocation. The old glob.c broke those rules too,
and the change should not make us any worse in that department. The code should
continue to work on all practical platforms that I know about; if you are aware
of any realistic counterexamples please let us know.
Paul Eggert
2017-09-02 21:39:39 UTC
Permalink
Raw Message
Post by Paul Eggert
assignment to an object changes its dynamic type.  It is not standard C.
  Standard C only allows one way to allocate untyped memory, and that is
malloc.
That should not be a problem, as Gnulib code regularly breaks those
standard-C rules when it comes to memory allocation.
in looking at the current Gnulib glob.c again, my previous email was too
pessimistic. Gnulib glob.c accesses the stack-allocated objects in
question only via char * pointers, and standard C (C11 section 6.5
paragraph 7 last line) has an exception for these accesses that makes
the glob.c code valid. So we should be OK even on theoretical platforms
that insist on strict conformance here.

Here's the Gnulib commit that the above analysis refers to:

http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=5f7d5f2b78d54258e8e2a41596bba0e123c75de4
Paul Eggert
2017-09-01 23:33:33 UTC
Permalink
Raw Message
Much of the lib/glob.c part of this patch comes from a glibc patch
proposed by Adhemerval Zanella in:
https://sourceware.org/ml/libc-alpha/2017-08/msg00456.html
* lib/glob.c: Do not include <config.h>, since <libc-config.h>,
included via glob.h, does this for us now.
(__set_errno): Remove, as libc-config does this for us now.
Include <scratch_buffer.h>.
(GETPW_R_SIZE_MAX): Remove.
(glob): Use struct scratch_buffer instead of extend_alloca.
* lib/glob.in.h: Include libc-config.h rather than
including <sys/cdefs.h> conditionally.
(__BEGIN_DECLS, __END_DECLS, __THROW, __THROWNL, attribute_hidden)
(__glibc_unlikely, __restrict, weak_alias):
Remove, as libc-config does this for us now.
* m4/glob.m4 (gl_PREREQ_GLOB):
Remove sys/cdefs.h tests; no longer needed.
* modules/glob (Depends-on): Add libc-config, scratch_buffer.
(glob.h): Do not replace HAVE_SYS_CDEFS_H.
---
ChangeLog | 20 ++++++++
lib/glob.c | 155 ++++++++++------------------------------------------------
lib/glob.in.h | 42 +---------------
m4/glob.m4 | 10 +---
modules/glob | 5 +-
5 files changed, 52 insertions(+), 180 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 078d5243c..a61d7755a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,25 @@
2017-09-01 Paul Eggert <***@cs.ucla.edu>

+ glob: use scratch_buffer instead of extend_alloca
+ Much of the lib/glob.c part of this patch comes from a glibc patch
+ proposed by Adhemerval Zanella in:
+ https://sourceware.org/ml/libc-alpha/2017-08/msg00456.html
+ * lib/glob.c: Do not include <config.h>, since <libc-config.h>,
+ included via glob.h, does this for us now.
+ (__set_errno): Remove, as libc-config does this for us now.
+ Include <scratch_buffer.h>.
+ (GETPW_R_SIZE_MAX): Remove.
+ (glob): Use struct scratch_buffer instead of extend_alloca.
+ * lib/glob.in.h: Include libc-config.h rather than
+ including <sys/cdefs.h> conditionally.
+ (__BEGIN_DECLS, __END_DECLS, __THROW, __THROWNL, attribute_hidden)
+ (__glibc_unlikely, __restrict, weak_alias):
+ Remove, as libc-config does this for us now.
+ * m4/glob.m4 (gl_PREREQ_GLOB):
+ Remove sys/cdefs.h tests; no longer needed.
+ * modules/glob (Depends-on): Add libc-config, scratch_buffer.
+ (glob.h): Do not replace HAVE_SYS_CDEFS_H.
+
scratch_buffer: new module
* lib/scratch_buffer.h, lib/scratch_buffer_grow.c:
* lib/scratch_buffer_grow_preserve.c:
diff --git a/lib/glob.c b/lib/glob.c
index 610d50a7f..596ae6c93 100644
--- a/lib/glob.c
+++ b/lib/glob.c
@@ -15,10 +15,6 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */

-#ifndef _LIBC
-# include <config.h>
-#endif
-
#include <glob.h>

#include <errno.h>
@@ -39,10 +35,6 @@
#endif

#include <errno.h>
-#ifndef __set_errno
-# define __set_errno(val) errno = (val)
-#endif
-
#include <dirent.h>
#include <stdlib.h>
#include <string.h>
@@ -82,12 +74,8 @@

#include <flexmember.h>
#include <glob_internal.h>
+#include <scratch_buffer.h>

-#ifdef _SC_GETPW_R_SIZE_MAX
-# define GETPW_R_SIZE_MAX() sysconf (_SC_GETPW_R_SIZE_MAX)
-#else
-# define GETPW_R_SIZE_MAX() (-1)
-#endif
#ifdef _SC_LOGIN_NAME_MAX
# define GET_LOGIN_NAME_MAX() sysconf (_SC_LOGIN_NAME_MAX)
#else
@@ -649,97 +637,43 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
if (success)
{
struct passwd *p;
- char *malloc_pwtmpbuf = NULL;
- char *pwtmpbuf;
# if defined HAVE_GETPWNAM_R || defined _LIBC
- long int pwbuflenmax = GETPW_R_SIZE_MAX ();
- size_t pwbuflen = pwbuflenmax;
struct passwd pwbuf;
int save = errno;
+ struct scratch_buffer pwtmpbuf;
+ scratch_buffer_init (&pwtmpbuf);

-# ifndef _LIBC
- if (! (0 < pwbuflenmax && pwbuflenmax <= SIZE_MAX))
- /* 'sysconf' does not support _SC_GETPW_R_SIZE_MAX.
- Try a moderate value. */
- pwbuflen = 1024;
-# endif
- if (glob_use_alloca (alloca_used, pwbuflen))
- pwtmpbuf = alloca_account (pwbuflen, alloca_used);
- else
- {
- pwtmpbuf = malloc (pwbuflen);
- if (pwtmpbuf == NULL)
- {
- if (__glibc_unlikely (malloc_name))
- free (name);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_pwtmpbuf = pwtmpbuf;
- }
-
- while (getpwnam_r (name, &pwbuf, pwtmpbuf, pwbuflen, &p)
+ while (getpwnam_r (name, &pwbuf,
+ pwtmpbuf.data, pwtmpbuf.length, &p)
!= 0)
{
- size_t newlen;
- bool v;
if (errno != ERANGE)
{
p = NULL;
break;
}
- v = size_add_wrapv (pwbuflen, pwbuflen, &newlen);
- if (!v && malloc_pwtmpbuf == NULL
- && glob_use_alloca (alloca_used, newlen))
- pwtmpbuf = extend_alloca_account (pwtmpbuf, pwbuflen,
- newlen, alloca_used);
- else
+ if (!scratch_buffer_grow (&pwtmpbuf))
{
- char *newp = (v ? NULL
- : realloc (malloc_pwtmpbuf, newlen));
- if (newp == NULL)
- {
- free (malloc_pwtmpbuf);
- if (__glibc_unlikely (malloc_name))
- free (name);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_pwtmpbuf = pwtmpbuf = newp;
+ retval = GLOB_NOSPACE;
+ goto out;
}
- pwbuflen = newlen;
__set_errno (save);
}
# else
- p = getpwnam (name);
+ p = getpwnam (pwtmpbuf.data);
# endif
- if (__glibc_unlikely (malloc_name))
- free (name);
if (p != NULL)
{
- if (malloc_pwtmpbuf == NULL)
- home_dir = p->pw_dir;
- else
+ home_dir = strdup (p->pw_dir);
+ malloc_home_dir = 1;
+ if (home_dir == NULL)
{
- size_t home_dir_len = strlen (p->pw_dir) + 1;
- if (glob_use_alloca (alloca_used, home_dir_len))
- home_dir = alloca_account (home_dir_len,
- alloca_used);
- else
- {
- home_dir = malloc (home_dir_len);
- if (home_dir == NULL)
- {
- free (pwtmpbuf);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_home_dir = 1;
- }
- memcpy (home_dir, p->pw_dir, home_dir_len);
+ scratch_buffer_free (&pwtmpbuf);
+ retval = GLOB_NOSPACE;
+ goto out;
}
}
- free (malloc_pwtmpbuf);
+ scratch_buffer_free (&pwtmpbuf);
}
else
{
@@ -876,59 +810,25 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
/* Look up specific user's home directory. */
{
struct passwd *p;
- char *malloc_pwtmpbuf = NULL;
+ struct scratch_buffer pwtmpbuf;
+ scratch_buffer_init (&pwtmpbuf);
+
# if defined HAVE_GETPWNAM_R || defined _LIBC
- long int buflenmax = GETPW_R_SIZE_MAX ();
- size_t buflen = buflenmax;
- char *pwtmpbuf;
struct passwd pwbuf;
int save = errno;

-# ifndef _LIBC
- if (! (0 <= buflenmax && buflenmax <= SIZE_MAX))
- /* Perhaps 'sysconf' does not support _SC_GETPW_R_SIZE_MAX. Try a
- moderate value. */
- buflen = 1024;
-# endif
- if (glob_use_alloca (alloca_used, buflen))
- pwtmpbuf = alloca_account (buflen, alloca_used);
- else
- {
- pwtmpbuf = malloc (buflen);
- if (pwtmpbuf == NULL)
- {
- nomem_getpw:
- if (__glibc_unlikely (malloc_user_name))
- free (user_name);
- retval = GLOB_NOSPACE;
- goto out;
- }
- malloc_pwtmpbuf = pwtmpbuf;
- }
-
- while (getpwnam_r (user_name, &pwbuf, pwtmpbuf, buflen, &p) != 0)
+ while (getpwnam_r (user_name, &pwbuf,
+ pwtmpbuf.data, pwtmpbuf.length, &p) != 0)
{
- size_t newlen;
- bool v;
if (errno != ERANGE)
{
p = NULL;
break;
}
- v = size_add_wrapv (buflen, buflen, &newlen);
- if (!v && malloc_pwtmpbuf == NULL
- && glob_use_alloca (alloca_used, newlen))
- pwtmpbuf = extend_alloca_account (pwtmpbuf, buflen,
- newlen, alloca_used);
- else
+ if (!scratch_buffer_grow (&pwtmpbuf))
{
- char *newp = v ? NULL : realloc (malloc_pwtmpbuf, newlen);
- if (newp == NULL)
- {
- free (malloc_pwtmpbuf);
- goto nomem_getpw;
- }
- malloc_pwtmpbuf = pwtmpbuf = newp;
+ retval = GLOB_NOSPACE;
+ goto out;
}
__set_errno (save);
}
@@ -957,7 +857,7 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
dirname = malloc (home_len + rest_len + 1);
if (dirname == NULL)
{
- free (malloc_pwtmpbuf);
+ scratch_buffer_free (&pwtmpbuf);
retval = GLOB_NOSPACE;
goto out;
}
@@ -968,13 +868,9 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),

dirlen = home_len + rest_len;
dirname_modified = 1;
-
- free (malloc_pwtmpbuf);
}
else
{
- free (malloc_pwtmpbuf);
-
if (flags & GLOB_TILDE_CHECK)
{
/* We have to regard it as an error if we cannot find the
@@ -983,6 +879,7 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
goto out;
}
}
+ scratch_buffer_free (&pwtmpbuf);
}
#endif /* !WINDOWS32 */
}
diff --git a/lib/glob.in.h b/lib/glob.in.h
index b0d27cff6..4f61705e2 100644
--- a/lib/glob.in.h
+++ b/lib/glob.in.h
@@ -20,9 +20,7 @@
#ifndef _GL_GLOB_H
#define _GL_GLOB_H

-#if @HAVE_SYS_CDEFS_H@
-# include <sys/cdefs.h>
-#endif
+#include <libc-config.h>

#include <stddef.h>

@@ -31,48 +29,10 @@
rely on 'struct stat'. */
#include <sys/stat.h>

-#ifndef __BEGIN_DECLS
-# ifdef __cplusplus
-# define __BEGIN_DECLS extern "C" {
-# define __END_DECLS }
-# else
-# define __BEGIN_DECLS
-# define __END_DECLS
-# endif
-#endif
-#ifndef __THROW
-# define __THROW
-#endif
-#ifndef __THROWNL
-# define __THROWNL
-#endif
-
-#define attribute_hidden
-
-#if __GNUC__ < 3
-# define __glibc_unlikely(cond) (cond)
-#else
-# define __glibc_unlikely(cond) __builtin_expect ((cond), 0)
-#endif
-
-/* GCC 2.95 and later have "__restrict", and C99 compilers have
- "restrict". */
-#if ! (defined __restrict || 2 < __GNUC__ + (95 <= __GNUC_MINOR__))
-# if 199901L <= __STDC_VERSION__
-# define __restrict restrict
-# else
-# define __restrict
-# endif
-#endif
-
#ifndef __USE_GNU
# define __USE_GNU 1
#endif

-#ifndef weak_alias
-# define weak_alias(name, alias)
-#endif
-

#define glob rpl_glob
#define globfree rpl_globfree
diff --git a/m4/glob.m4 b/m4/glob.m4
index 189cd3a18..d64e70de4 100644
--- a/m4/glob.m4
+++ b/m4/glob.m4
@@ -1,4 +1,4 @@
-# glob.m4 serial 15
+# glob.m4 serial 16
dnl Copyright (C) 2005-2007, 2009-2017 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -65,12 +65,6 @@ AC_DEFUN([gl_PREREQ_GLOB],
AC_REQUIRE([gl_CHECK_TYPE_STRUCT_DIRENT_D_TYPE])dnl
AC_REQUIRE([AC_C_RESTRICT])dnl
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])dnl
- AC_CHECK_HEADERS_ONCE([sys/cdefs.h unistd.h])dnl
- if test $ac_cv_header_sys_cdefs_h = yes; then
- HAVE_SYS_CDEFS_H=1
- else
- HAVE_SYS_CDEFS_H=0
- fi
- AC_SUBST([HAVE_SYS_CDEFS_H])
+ AC_CHECK_HEADERS_ONCE([unistd.h])dnl
AC_CHECK_FUNCS_ONCE([getlogin_r getpwnam_r])dnl
])
diff --git a/modules/glob b/modules/glob
index 98d49e34f..2ea73e803 100644
--- a/modules/glob
+++ b/modules/glob
@@ -24,10 +24,12 @@ d-type [test -n "$GLOB_H"]
flexmember [test -n "$GLOB_H"]
fnmatch [test -n "$GLOB_H"]
getlogin_r [test -n "$GLOB_H"]
+libc-config [test -n "$GLOB_H"]
memchr [test -n "$GLOB_H"]
mempcpy [test -n "$GLOB_H"]
opendir [test -n "$GLOB_H"]
readdir [test -n "$GLOB_H"]
+scratch_buffer [test -n "$GLOB_H"]
stdbool [test -n "$GLOB_H"]
stdint [test -n "$GLOB_H"]
strdup [test -n "$GLOB_H"]
@@ -53,8 +55,7 @@ if GL_GENERATE_GLOB_H
glob.h: glob.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(WARN_ON_USE_H)
$(AM_V_GEN)rm -f $@-t $@ && \
{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
- sed -e 's|@''HAVE_SYS_CDEFS_H''@|$(HAVE_SYS_CDEFS_H)|g' \
- -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+ sed -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
-e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
< $(srcdir)/glob.in.h; \
} > $@-t && \
--
2.13.5
Loading...