Bug#680292: gnatmake: linker arguments order incompatible with --as-needed
Package: gnat-4.6
Version: 4.6.3-4
Severity: minor
Hello. Gnatmake calls gcc -shared in a way incompatible with
--as-needed. Gprbuild uses a better ordering.
-- bug.ads
package Bug is
end Bug;
-- bug.gpr
project Bug is
for Library_Name use "bug";
for Library_Version use "libbug.so.1";
for Library_Kind use "dynamic";
for Library_Dir use "lib";
for Library_Options use ("-lncurses");
end Bug;
$ mkdir lib
$ gnatmake -v -Pbug
...
/usr//bin/gcc-4.6 -shared ... -lncurses ... -lgnat-4.6 -Wl,-soname,libbug.so.1 /tmp/bug/bug.o
...
$ gnatclean -Pbug
...
$ gprbuild -v -Pbug
...
/usr/bin/gcc-4.6 -shared ... -lgnat-4.6 ... -Wl,-soname,libbug.so.1 /tmp/bug/bug.o -lncurses
...
When adding -Wl,--as-needed before -lncurses in Library_Options (or
using GNU gold linker with default options), symbols from -lgnat-4.6
are ignored because they are not used by any object *yet*. In this
minimal example, this is not a problem, but any useful library will
use symbols from -lgnat-4.6.
As a more real-life example, read dpkg_shlibdeps warnings when building
libtexttools-2.1.0-1 with
LDFLAGS += -Wl,--as-needed # or remove the lines stripping it
BUILDER_OPTIONS += -v
-- System Information:
ii gcc-4.6 4.6.3-1
Reply to: