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| author | Simon McVittie <smcv@collabora.com> | 2020-06-29 18:28:38 +0100 |
|---|---|---|
| committer | Simon McVittie <smcv@collabora.com> | 2020-07-02 09:54:40 +0100 |
| commit | ca80d5127e56dd2ee056fdf3f4204017b78b89e0 (patch) | |
| tree | 3cf29d010a9a4962800262bc910adcaaa8ce62cd /configure.ac | |
| parent | 52dfc3dd4a766fc2f1a19edad5d5cfdd21e0ec27 (diff) | |
| download | jansson-ca80d5127e56dd2ee056fdf3f4204017b78b89e0.zip jansson-ca80d5127e56dd2ee056fdf3f4204017b78b89e0.tar.gz jansson-ca80d5127e56dd2ee056fdf3f4204017b78b89e0.tar.bz2 | |
build: Add a symbol version to all exported symbols for glibc
The --default-symver linker option attaches a default version definition
(the SONAME) to every exported symbol. It is supported since at least
GNU binutils 2.22 in 2011 (older versions not tested).
With this version definition, newly-linked binaries that depend on the
jansson shared library will refer to its symbols in a versioned form,
preventing their references from being resolved to a symbol of the same
name exported by json-c or json-glib if those libraries appear in
dependency search order before jansson, which will usually result in
a crash. This is necessary because ELF symbol resolution normally uses
a single flat namespace, not a tree like Windows symbol resolution.
At least one symbol (json_object_iter_next()) is exported by all three
JSON libraries.
Linking with -Bsymbolic is not enough to have this effect in all cases,
because -Bsymbolic only affects symbol lookup within a shared object,
for example when parse_json() calls json_decref(). It does not affect
calls from external code into jansson, unless jansson was statically
linked into the external caller.
This change will also not prevent code that depends on json-c or
json-glib from finding jansson's symbols and crashing; to prevent
that, a corresponding change in json-c or json-glib would be needed.
Adding a symbol-version is a backwards-compatible change, but once
added, removing or changing the symbol-version would be an incompatible
change that requires a SONAME bump.
Resolves: https://github.com/akheron/jansson/issues/523
(when combined with an equivalent change to json-c).
Signed-off-by: Simon McVittie <smcv@collabora.com>
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index d923eef..3a4d187 100644 --- a/configure.ac +++ b/configure.ac @@ -137,6 +137,10 @@ fi AS_IF([test "x$with_Bsymbolic" = "xyes"], [JSON_BSYMBOLIC_LDFLAGS=-Wl[,]-Bsymbolic-functions]) AC_SUBST(JSON_BSYMBOLIC_LDFLAGS) +# Enable symbol versioning on GNU libc +JSON_SYMVER_LDFLAGS= +AC_CHECK_DECL([__GLIBC__], [JSON_SYMVER_LDFLAGS=-Wl,--default-symver]) +AC_SUBST([JSON_SYMVER_LDFLAGS]) AC_ARG_ENABLE([ossfuzzers], [AS_HELP_STRING([--enable-ossfuzzers], |