[PATCH] libiberty, include: add bsearch_r
Nick Alcock
nick.alcock@oracle.com
Tue Jun 23 14:53:53 GMT 2020
libctf wants a bsearch that takes a void * arg pointer to avoid a
nonportable use of __thread.
bsearch_r is required, not optional, at this point because as far as I
can see this obvious-sounding function is not implemented by anyone's
libc. We can easily move it to AC_LIBOBJ later if it proves necessary
to do so.
include/
* libiberty.h (bsearch_r): New.
libiberty/
* bsearch_r.c: New file.
* Makefile.in (CFILES): Add bsearch_r.c.
(REQUIRED_OFILES): Add bsearch_r.o.
* functions.texi: Regenerate.
---
include/libiberty.h | 7 ++++
libiberty/Makefile.in | 12 +++++-
libiberty/bsearch_r.c | 93 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 111 insertions(+), 1 deletion(-)
create mode 100644 libiberty/bsearch_r.c
Acked six months ago (!) by Jeff Law here:
<https://gcc.gnu.org/pipermail/gcc-patches/2020-January/538248.html>
Rebased against master (commit efc16503ca10bc0e934e0bace5777500e4dc757a)
and retested building this morning.
Sorry for the delay.
diff --git a/include/libiberty.h b/include/libiberty.h
index 141cb886a85..0bb5b81d4ac 100644
--- a/include/libiberty.h
+++ b/include/libiberty.h
@@ -641,6 +641,13 @@ extern int pexecute (const char *, char * const *, const char *,
extern int pwait (int, int *, int);
+/* Like bsearch, but takes and passes on an argument like qsort_r. */
+
+extern void *bsearch_r (register const void *, const void *,
+ size_t, register size_t,
+ register int (*)(const void *, const void *, void *),
+ void *);
+
#if defined(HAVE_DECL_ASPRINTF) && !HAVE_DECL_ASPRINTF
/* Like sprintf but provides a pointer to malloc'd storage, which must
be freed by the caller. */
diff --git a/libiberty/Makefile.in b/libiberty/Makefile.in
index d6b302e02fd..895f701bcd0 100644
--- a/libiberty/Makefile.in
+++ b/libiberty/Makefile.in
@@ -124,7 +124,7 @@ COMPILE.c = $(CC) -c @DEFS@ $(CFLAGS) $(CPPFLAGS) -I. -I$(INCDIR) \
# CONFIGURED_OFILES and funcs in configure.ac. Also run "make maint-deps"
# to build the new rules.
CFILES = alloca.c argv.c asprintf.c atexit.c \
- basename.c bcmp.c bcopy.c bsearch.c bzero.c \
+ basename.c bcmp.c bcopy.c bsearch.c bsearch_r.c bzero.c \
calloc.c choose-temp.c clock.c concat.c cp-demangle.c \
cp-demint.c cplus-dem.c crc32.c \
d-demangle.c dwarfnames.c dyn-string.c \
@@ -168,6 +168,7 @@ REQUIRED_OFILES = \
./regex.$(objext) ./cplus-dem.$(objext) ./cp-demangle.$(objext) \
./md5.$(objext) ./sha1.$(objext) ./alloca.$(objext) \
./argv.$(objext) \
+ ./bsearch_r.$(objext) \
./choose-temp.$(objext) ./concat.$(objext) \
./cp-demint.$(objext) ./crc32.$(objext) ./d-demangle.$(objext) \
./dwarfnames.$(objext) ./dyn-string.$(objext) \
@@ -601,6 +602,15 @@ $(CONFIGURED_OFILES): stamp-picdir stamp-noasandir
else true; fi
$(COMPILE.c) $(srcdir)/bsearch.c $(OUTPUT_OPTION)
+./bsearch_r.$(objext): $(srcdir)/bsearch_r.c config.h $(INCDIR)/ansidecl.h
+ if [ x"$(PICFLAG)" != x ]; then \
+ $(COMPILE.c) $(PICFLAG) $(srcdir)/bsearch_r.c -o pic/$@; \
+ else true; fi
+ if [ x"$(NOASANFLAG)" != x ]; then \
+ $(COMPILE.c) $(PICFLAG) $(NOASANFLAG) $(srcdir)/bsearch_r.c -o noasan/$@; \
+ else true; fi
+ $(COMPILE.c) $(srcdir)/bsearch_r.c $(OUTPUT_OPTION)
+
./bzero.$(objext): $(srcdir)/bzero.c
if [ x"$(PICFLAG)" != x ]; then \
$(COMPILE.c) $(PICFLAG) $(srcdir)/bzero.c -o pic/$@; \
diff --git a/libiberty/bsearch_r.c b/libiberty/bsearch_r.c
new file mode 100644
index 00000000000..79ebae9b0be
--- /dev/null
+++ b/libiberty/bsearch_r.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 1990 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. [rescinded 22 July 1999]
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+
+@deftypefn Supplemental void* bsearch_r (const void *@var{key}, @
+ const void *@var{base}, size_t @var{nmemb}, size_t @var{size}, @
+ int (*@var{compar})(const void *, const void *, void *), void *@var{arg})
+
+Performs a search over an array of @var{nmemb} elements pointed to by
+@var{base} for a member that matches the object pointed to by @var{key}.
+The size of each member is specified by @var{size}. The array contents
+should be sorted in ascending order according to the @var{compar}
+comparison function. This routine should take three arguments: the first
+two point to the @var{key} and to an array member, and the last is passed
+down unchanged from @code{bsearch_r}'s last argument. It should return an
+integer less than, equal to, or greater than zero if the @var{key} object
+is respectively less than, matching, or greater than the array member.
+
+@end deftypefn
+
+*/
+
+#include "config.h"
+#include "ansidecl.h"
+#include <sys/types.h> /* size_t */
+#include <stdio.h>
+
+/*
+ * Perform a binary search.
+ *
+ * The code below is a bit sneaky. After a comparison fails, we
+ * divide the work in half by moving either left or right. If lim
+ * is odd, moving left simply involves halving lim: e.g., when lim
+ * is 5 we look at item 2, so we change lim to 2 so that we will
+ * look at items 0 & 1. If lim is even, the same applies. If lim
+ * is odd, moving right again involes halving lim, this time moving
+ * the base up one item past p: e.g., when lim is 5 we change base
+ * to item 3 and make lim 2 so that we will look at items 3 and 4.
+ * If lim is even, however, we have to shrink it by one before
+ * halving: e.g., when lim is 4, we still looked at item 2, so we
+ * have to make lim 3, then halve, obtaining 1, so that we will only
+ * look at item 3.
+ */
+void *
+bsearch_r (register const void *key, const void *base0,
+ size_t nmemb, register size_t size,
+ register int (*compar)(const void *, const void *, void *),
+ void *arg)
+{
+ register const char *base = (const char *) base0;
+ register int lim, cmp;
+ register const void *p;
+
+ for (lim = nmemb; lim != 0; lim >>= 1) {
+ p = base + (lim >> 1) * size;
+ cmp = (*compar)(key, p, arg);
+ if (cmp == 0)
+ return (void *)p;
+ if (cmp > 0) { /* key > p: move right */
+ base = (const char *)p + size;
+ lim--;
+ } /* else move left */
+ }
+ return (NULL);
+}
--
2.27.0.247.g3dff7de930
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