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authorLasse Collin <lasse.collin@tukaani.org>2022-11-24 14:52:44 +0200
committerLasse Collin <lasse.collin@tukaani.org>2022-11-24 14:52:44 +0200
commit06824396b2b6c84f3a235cb7c19c2a9701167797 (patch)
tree1586fd8a6b7f2895b3e0081bdba4c31d51454e17 /src
parentliblzma: Refactor to use lzma_filters_free(). (diff)
downloadxz-06824396b2b6c84f3a235cb7c19c2a9701167797.tar.xz
Build: Don't put GNU/Linux-specific symbol versions into static liblzma.
It not only makes no sense to put symbol versions into a static library but it can also cause breakage. By default Libtool #defines PIC if building a shared library and doesn't define it for static libraries. This is documented in the Libtool manual. It can be overriden using --with-pic or --without-pic. configure.ac detects if --with-pic or --without-pic is used and then gives an error if neither --disable-shared nor --disable-static was used at the same time. Thus, in normal situations it works to build both shared and static library at the same time on GNU/Linux, only --with-pic or --without-pic requires that only one type of library is built. Thanks to John Paul Adrian Glaubitz from Debian for reporting the problem that occurred on ia64: https://www.mail-archive.com/xz-devel@tukaani.org/msg00610.html
Diffstat (limited to 'src')
-rw-r--r--src/liblzma/common/common.h12
1 files changed, 12 insertions, 0 deletions
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index 1ca536be..b3a624c6 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -34,6 +34,18 @@
#include "lzma.h"
+// The extra symbol versioning in the C files may only be used when
+// building a shared library. If HAVE_SYMBOL_VERSIONS_LINUX is defined
+// to 2 then symbol versioning is done only if also PIC is defined.
+// By default Libtool defines PIC when building a shared library and
+// doesn't define it when building a static library but it can be
+// overriden with --with-pic and --without-pic. configure let's rely
+// on PIC if neither --with-pic or --without-pic was used.
+#if defined(HAVE_SYMBOL_VERSIONS_LINUX) \
+ && (HAVE_SYMBOL_VERSIONS_LINUX == 2 && !defined(PIC))
+# undef HAVE_SYMBOL_VERSIONS_LINUX
+#endif
+
#ifdef HAVE_SYMBOL_VERSIONS_LINUX
// To keep link-time optimization (LTO, -flto) working with GCC,
// the __symver__ attribute must be used instead of __asm__(".symver ...").