Skip to contentSkip to conversation

cmake: Fix RPATH for host libraries built by CMake

PATCH New Jan Kundrát 3 participants 4 messages Mar 12, 2018 – Apr 6, 2018

lore
Share & tools
lore

Jan Kundrát

author
#0 lore raw

PATCH 1/1 cmake: Fix RPATH for host libraries built by CMake

The host shared libraries produced by CMake were missing a proper DT_RPATH. That became a problem because the DT_RPATH handling is not transitive by design.

Consider the following scenario:

- pkg-a provides a library (liba) which links to libpcre
- pkg-b provides a binary (foo) and a shared library (libb) which is needed by that binary
- libb links to liba
- pkg-a and pkg-b are both built by CMake

In this scenario, foo is correctly marked with DT_RPATH pointing to host/lib/, but that path is not used when (recursively) resolving PCRE's symbols in liba. When attempting to run the foo binary, the linker correctly finds both liba and libb, but it cannot find the libpcre.so as built by Buildroot for host.

Signed-off-by Jan Kundr?t <[email protected]>
---
 package/pkg-cmake.mk | 1 +
 1 file changed, 1 insertion(+)
package/pkg-cmake.mk +1 -0
index 14ffe4a88f..9b07798a1e 100644
@@ -132,6 +132,7 @@ define $(2)_CONFIGURE_CMDS
 		-DCMAKE_C_FLAGS="$$(HOST_CFLAGS)" \
 		-DCMAKE_CXX_FLAGS="$$(HOST_CXXFLAGS)" \
 		-DCMAKE_EXE_LINKER_FLAGS="$$(HOST_LDFLAGS)" \
+		-DCMAKE_SHARED_LINKER_FLAGS="$$(HOST_LDFLAGS)" \
 		-DCMAKE_ASM_COMPILER="$$(HOSTAS)" \
 		-DCMAKE_C_COMPILER="$$(CMAKE_HOST_C_COMPILER)" \
 		-DCMAKE_CXX_COMPILER="$$(CMAKE_HOST_CXX_COMPILER)" \
Signature · 1 line
2.16.2
#1 lore raw

PATCH 1/1 cmake: Fix RPATH for host libraries built by CMake

Hi Jan, all,

Quoted 28 lines · Jan Kundr?t

The host shared libraries produced by CMake were missing a proper DT_RPATH. That became a problem because the DT_RPATH handling is not transitive by design.

Consider the following scenario:

- pkg-a provides a library (liba) which links to libpcre
- pkg-b provides a binary (foo) and a shared library (libb) which is needed by that binary
- libb links to liba
- pkg-a and pkg-b are both built by CMake

In this scenario, foo is correctly marked with DT_RPATH pointing to host/lib/, but that path is not used when (recursively) resolving PCRE's symbols in liba. When attempting to run the foo binary, the linker correctly finds both liba and libb, but it cannot find the libpcre.so as built by Buildroot for host.

Signed-off-by Jan Kundr?t <[email protected]>
---
 package/pkg-cmake.mk | 1 +
 1 file changed, 1 insertion(+)
package/pkg-cmake.mk +0 -0
index 14ffe4a88f..9b07798a1e 100644

package/pkg-cmake.mk define $(2)_CONFIGURE_CMDS · line 135

Quoted 4 lines
package/pkg-cmake.mk +1 -0
@@ -132,6 +132,7 @@ define $(2)_CONFIGURE_CMDS
                -DCMAKE_C_FLAGS="$$(HOST_CFLAGS)" \
                -DCMAKE_CXX_FLAGS="$$(HOST_CXXFLAGS)" \
                -DCMAKE_EXE_LINKER_FLAGS="$$(HOST_LDFLAGS)" \
+               -DCMAKE_SHARED_LINKER_FLAGS="$$(HOST_LDFLAGS)" \

hmm... I though this was already in Buildroot... I must mix up with something else :-/

Quoted 11 lines
package/pkg-cmake.mk +0 -1
                -DCMAKE_ASM_COMPILER="$$(HOSTAS)" \
                -DCMAKE_C_COMPILER="$$(CMAKE_HOST_C_COMPILER)" \
                -DCMAKE_CXX_COMPILER="$$(CMAKE_HOST_CXX_COMPILER)" \
--

2.16.2

_______________________________________________
buildroot mailing list
buildroot at busybox.net
http://lists.busybox.net/mailman/listinfo/buildroot

Reviewed-by Samuel Martin <[email protected]>

Regard,

Signature · 1 line
Samuel
#2 lore raw

PATCH 1/1 cmake: Fix RPATH for host libraries built by CMake

In reply to Jan Kundrát
Quoted 14 lines
Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line

"Jan" == Jan Kundr?t <[email protected]> writes:

The host shared libraries produced by CMake were missing a proper DT_RPATH. That became a problem because the DT_RPATH handling is not transitive by design.

Consider the following scenario:

- pkg-a provides a library (liba) which links to libpcre
- pkg-b provides a binary (foo) and a shared library (libb) which is needed by that binary
- libb links to liba
- pkg-a and pkg-b are both built by CMake

Quoted 7 lines

In this scenario, foo is correctly marked with DT_RPATH pointing to host/lib/, but that path is not used when (recursively) resolving PCRE's symbols in liba. When attempting to run the foo binary, the linker correctly finds both liba and libb, but it cannot find the libpcre.so as built by Buildroot for host.

Signed-off-by Jan Kundr?t <[email protected]>

Committed, thanks.

Signature · 1 line
Bye, Peter Korsgaard
#3 lore raw

PATCH 1/1 cmake: Fix RPATH for host libraries built by CMake

In reply to Jan Kundrát
Quoted 14 lines
Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line

"Jan" == Jan Kundr?t <[email protected]> writes:

The host shared libraries produced by CMake were missing a proper DT_RPATH. That became a problem because the DT_RPATH handling is not transitive by design.

Consider the following scenario:

- pkg-a provides a library (liba) which links to libpcre
- pkg-b provides a binary (foo) and a shared library (libb) which is needed by that binary
- libb links to liba
- pkg-a and pkg-b are both built by CMake

Quoted 7 lines

In this scenario, foo is correctly marked with DT_RPATH pointing to host/lib/, but that path is not used when (recursively) resolving PCRE's symbols in liba. When attempting to run the foo binary, the linker correctly finds both liba and libb, but it cannot find the libpcre.so as built by Buildroot for host.

Signed-off-by Jan Kundr?t <[email protected]>

Committed to 2018.02.x, thanks.

Signature · 1 line
Bye, Peter Korsgaard