From 008dd9771057dbbd7ce971c43bce2a0b05e2cf97 Mon Sep 17 00:00:00 2001
From: Baruch Siach <baruch@tkos.co.il>
Date: Sun, 21 Aug 2016 08:56:57 +0300
Subject: [PATCH] lib/memory: fix indirect static link with zlib

quagga SNMP support depends on netsnmp, that optionally depends on OpenSSL,
which in turn requires zlib. zlib exports the 'zcalloc' symbol, which collides
with a function of the same name in memory.c. This is not a problem when
linking dynamically, since quagga does not use zlib directly. But static
linking fails with the error:

  CCLD     ospfd
.../output/host/usr/mips64el-buildroot-linux-uclibc/sysroot/usr/lib/libz.a(zutil.o): In function `zcalloc':
zutil.c:(.text+0x48): multiple definition of `zcalloc'
.../output/build/quagga-1.0.20160315/lib/.libs/libzebra.a(memory.o):memory.c:(.text+0x1a0): first defined here

Rename 'zcalloc' to 'zzcalloc' to avoid symbol collision.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
Patch status: posted upstream
https://lists.quagga.net/pipermail/quagga-dev/2016-August/016109.html

 lib/memory.c | 14 ++++++++------
 lib/memory.h |  4 ++--
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/memory.c b/lib/memory.c
index 269520d5a435..b1680a5e6f07 100644
--- a/lib/memory.c
+++ b/lib/memory.c
@@ -80,9 +80,11 @@ zmalloc (int type, size_t size)
 
 /*
  * Allocate memory as in zmalloc, and also clear the memory.
+ * Add an extra 'z' prefix to function name to avoid collision when linking
+ * statically with zlib that exports the 'zcalloc' symbol.
  */
 void *
-zcalloc (int type, size_t size)
+zzcalloc (int type, size_t size)
 {
   void *memory;
 
@@ -97,9 +99,9 @@ zcalloc (int type, size_t size)
 }
 
 /* 
- * Given a pointer returned by zmalloc or zcalloc, free it and
+ * Given a pointer returned by zmalloc or zzcalloc, free it and
  * return a pointer to a new size, basically acting like realloc().
- * Requires: ptr was returned by zmalloc, zcalloc, or zrealloc with the
+ * Requires: ptr was returned by zmalloc, zzcalloc, or zrealloc with the
  * same type.
  * Effects: Returns a pointer to the new memory, or aborts.
  */
@@ -109,7 +111,7 @@ zrealloc (int type, void *ptr, size_t size)
   void *memory;
 
   if (ptr == NULL)              /* is really alloc */
-      return zcalloc(type, size);
+      return zzcalloc(type, size);
 
   memory = realloc (ptr, size);
   if (memory == NULL)
@@ -122,7 +124,7 @@ zrealloc (int type, void *ptr, size_t size)
 
 /*
  * Free memory allocated by z*alloc or zstrdup.
- * Requires: ptr was returned by zmalloc, zcalloc, or zrealloc with the
+ * Requires: ptr was returned by zmalloc, zzcalloc, or zrealloc with the
  * same type.
  * Effects: The memory is freed and may no longer be referenced.
  */
@@ -196,7 +198,7 @@ mtype_zcalloc (const char *file, int line, int type, size_t size)
   mstat[type].c_calloc++;
   mstat[type].t_calloc++;
 
-  memory = zcalloc (type, size);
+  memory = zzcalloc (type, size);
   mtype_log ("xcalloc", memory, file, line, type);
 
   return memory;
diff --git a/lib/memory.h b/lib/memory.h
index 23962235dbfe..501352993d21 100644
--- a/lib/memory.h
+++ b/lib/memory.h
@@ -56,7 +56,7 @@ extern struct mlist mlists[];
   mtype_zstrdup (__FILE__, __LINE__, (mtype), (str))
 #else
 #define XMALLOC(mtype, size)       zmalloc ((mtype), (size))
-#define XCALLOC(mtype, size)       zcalloc ((mtype), (size))
+#define XCALLOC(mtype, size)       zzcalloc ((mtype), (size))
 #define XREALLOC(mtype, ptr, size) zrealloc ((mtype), (ptr), (size))
 #define XFREE(mtype, ptr)          do { \
                                      zfree ((mtype), (ptr)); \
@@ -67,7 +67,7 @@ extern struct mlist mlists[];
 
 /* Prototypes of memory function. */
 extern void *zmalloc (int type, size_t size);
-extern void *zcalloc (int type, size_t size);
+extern void *zzcalloc (int type, size_t size);
 extern void *zrealloc (int type, void *ptr, size_t size);
 extern void  zfree (int type, void *ptr);
 extern char *zstrdup (int type, const char *str);
-- 
2.8.1