Fix crash when libcxxrt exceptions been freed by a different language runtime,

and when libcxxrt itself free foreign exceptions.

Unwind API was specifically designed to allow mixed language environments where
exceptions from different runtimes interoperate. One particular example is
C++/LuaJit combination. Due to the issues in libcxxrt, databases/tarantool crashes
when linked against libcxxrt.

The issue was merged by upstream butat the moment not officially released.
https://github.com/pathscale/libcxxrt/pull/32

PR:		204786
Submitted by:	Nick Zavaritsky <mejedi@gmail.com>
Approved by:	Mahdi Mokhtari <mokhi64@gmail.com> (maintainer)

5 files changed, 203 insertions, 2 deletions

diff --git a/devel/libcxxrt/Makefile b/devel/libcxxrt/Makefile
index 81429375b9e7..7ef5077fdbcb 100644
--- a/devel/libcxxrt/Makefile
+++ b/devel/libcxxrt/Makefile
@@ -2,7 +2,7 @@
 
 PORTNAME=	libcxxrt
 PORTVERSION=	20131225
-PORTREVISION=	2
+PORTREVISION=	3
 CATEGORIES=	devel
 
 MAINTAINER=	mokhi64@gmail.com
@@ -15,6 +15,7 @@ GH_ACCOUNT=	pathscale
 GH_TAGNAME=	2f150a6
 
 USES=		cmake compiler:c++11-lang
+USE_LDCONFIG=	yes
 CXXFLAGS+=	-nostdlib
 
 do-install:
diff --git a/devel/libcxxrt/files/patch-src_exception.cc b/devel/libcxxrt/files/patch-src_exception.cc
new file mode 100644
index 000000000000..2c4dfa5058c7
--- /dev/null
+++ b/devel/libcxxrt/files/patch-src_exception.cc
@@ -0,0 +1,48 @@
+--- src/exception.cc.orig	2013-12-26 03:11:27 UTC
++++ src/exception.cc
+@@ -304,13 +304,17 @@ static pthread_key_t eh_key;
+ static void exception_cleanup(_Unwind_Reason_Code reason, 
+                               struct _Unwind_Exception *ex)
+ {
+-	__cxa_free_exception(static_cast<void*>(ex));
++	// Exception layout:
++	// [__cxa_exception [_Unwind_Exception]] [exception object]
++	//
++	// __cxa_free_exception expects a pointer to the exception object
++	__cxa_free_exception(static_cast<void*>(ex + 1));
+ }
+ static void dependent_exception_cleanup(_Unwind_Reason_Code reason, 
+                               struct _Unwind_Exception *ex)
+ {
+ 
+-	__cxa_free_dependent_exception(static_cast<void*>(ex));
++	__cxa_free_dependent_exception(static_cast<void*>(ex + 1));
+ }
+ 
+ /**
+@@ -340,7 +344,8 @@ static void thread_cleanup(void* thread_
+ 		if (info->foreign_exception_state != __cxa_thread_info::none)
+ 		{
+ 			_Unwind_Exception *e = reinterpret_cast<_Unwind_Exception*>(info->globals.caughtExceptions);
+-			e->exception_cleanup(_URC_FOREIGN_EXCEPTION_CAUGHT, e);
++			if (e->exception_cleanup)
++				e->exception_cleanup(_URC_FOREIGN_EXCEPTION_CAUGHT, e);
+ 		}
+ 		else
+ 		{
+@@ -1270,12 +1275,13 @@ extern "C" void __cxa_end_catch()
+ 	
+ 	if (ti->foreign_exception_state != __cxa_thread_info::none)
+ 	{
+-		globals->caughtExceptions = 0;
+ 		if (ti->foreign_exception_state != __cxa_thread_info::rethrown)
+ 		{
+ 			_Unwind_Exception *e = reinterpret_cast<_Unwind_Exception*>(ti->globals.caughtExceptions);
+-			e->exception_cleanup(_URC_FOREIGN_EXCEPTION_CAUGHT, e);
++			if (e->exception_cleanup)
++				e->exception_cleanup(_URC_FOREIGN_EXCEPTION_CAUGHT, e);
+ 		}
++		globals->caughtExceptions = 0;
+ 		ti->foreign_exception_state = __cxa_thread_info::none;
+ 		return;
+ 	}
diff --git a/devel/libcxxrt/files/patch-test_CMakeLists.txt b/devel/libcxxrt/files/patch-test_CMakeLists.txt
new file mode 100644
index 000000000000..11114df9d65a
--- /dev/null
+++ b/devel/libcxxrt/files/patch-test_CMakeLists.txt
@@ -0,0 +1,24 @@
+--- test/CMakeLists.txt.orig	2013-12-26 03:11:27 UTC
++++ test/CMakeLists.txt
+@@ -23,6 +23,11 @@ add_executable(cxxrt-test-shared ${CXXTE
+ set_property(TARGET cxxrt-test-shared PROPERTY LINK_FLAGS -nodefaultlibs)
+ target_link_libraries(cxxrt-test-shared cxxrt-shared pthread dl c)
+ 
++include_directories(${CMAKE_SOURCE_DIR}/src)
++add_executable(cxxrt-test-foreign-exceptions test_foreign_exceptions.cc)
++set_property(TARGET cxxrt-test-foreign-exceptions PROPERTY LINK_FLAGS "-nodefaultlibs -Wl,--wrap,_Unwind_RaiseException")
++target_link_libraries(cxxrt-test-foreign-exceptions cxxrt-static gcc_s pthread dl c)
++
+ add_test(cxxrt-test-static-test
+          ${CMAKE_CURRENT_SOURCE_DIR}/run_test.sh
+          ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/cxxrt-test-static
+@@ -35,6 +40,9 @@ add_test(cxxrt-test-shared-test
+          ${CMAKE_CURRENT_BINARY_DIR}/expected_output.log
+          ${CMAKE_CURRENT_BINARY_DIR}/test-shared-output.log)
+ 
++add_test(cxxrt-test-foreign-exceptions
++         ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/cxxrt-test-foreign-exceptions)
++
+ set(valgrind "valgrind -q")
+ 
+ if(TEST_VALGRIND)
diff --git a/devel/libcxxrt/files/patch-test_test__foreign__exceptions.cc b/devel/libcxxrt/files/patch-test_test__foreign__exceptions.cc
new file mode 100644
index 000000000000..baaaf2ee1bc4
--- /dev/null
+++ b/devel/libcxxrt/files/patch-test_test__foreign__exceptions.cc
@@ -0,0 +1,128 @@
+--- test/test_foreign_exceptions.cc.orig	2016-05-29 13:30:15 UTC
++++ test/test_foreign_exceptions.cc
+@@ -0,0 +1,125 @@
++#include <cstdio>
++#include <cstdlib>
++#include "unwind.h"
++
++#define EXCEPTION_CLASS(a,b,c,d,e,f,g,h) \
++	((static_cast<uint64_t>(a) << 56) +\
++	 (static_cast<uint64_t>(b) << 48) +\
++	 (static_cast<uint64_t>(c) << 40) +\
++	 (static_cast<uint64_t>(d) << 32) +\
++	 (static_cast<uint64_t>(e) << 24) +\
++	 (static_cast<uint64_t>(f) << 16) +\
++	 (static_cast<uint64_t>(g) << 8) +\
++	 (static_cast<uint64_t>(h)))
++
++// using ld --wrap=_Unwind_RaiseException hook feature
++extern "C" _Unwind_Reason_Code __real__Unwind_RaiseException (_Unwind_Exception *e);
++extern "C" _Unwind_Reason_Code __wrap__Unwind_RaiseException (_Unwind_Exception *e);
++
++extern "C" _Unwind_Reason_Code __wrap__Unwind_RaiseException (_Unwind_Exception *e)
++{
++	// clobber exception class forcing libcxx own exceptions to be treated
++	// as foreign exception within libcxx itself
++	e->exception_class = EXCEPTION_CLASS('F','O','R','E','I','G','N','\0');
++	__real__Unwind_RaiseException(e);
++}
++
++_Unwind_Exception global_e;
++
++enum test_status {
++	PENDING, PASSED, FAILED
++};
++
++const char test_status_str[][8] = {
++	"PENDING", "PASSED", "FAILED"
++};
++
++test_status test1_status = PENDING;
++test_status test2_status = PENDING;
++test_status test3_status = PENDING;
++
++void test2_exception_cleanup(_Unwind_Reason_Code code, _Unwind_Exception *e)
++{
++	fputs("(2) exception_cleanup called\n", stderr);
++	if (e != &global_e) {
++		fprintf(stderr, "(2) ERROR: unexpected ptr: expecting %p, got %p\n", &global_e, e);
++		test2_status = FAILED;
++	}
++	if (test2_status == PENDING)
++		test2_status = PASSED;
++}
++
++struct test3_exception
++{
++	static int counter;
++	~test3_exception()
++	{
++		counter++;
++		fputs("(3) exception dtor\n", stderr);
++	}
++};
++int test3_exception::counter = 0;
++
++int main()
++{
++	///////////////////////////////////////////////////////////////
++	fputs("(1) foreign exception, exception_cleanup=nullptr\n", stderr);
++	try
++	{
++		global_e.exception_class = 0;
++		global_e.exception_cleanup = 0;
++		__real__Unwind_RaiseException(&global_e);
++	}
++	catch (...)
++	{
++	}
++	test1_status = PASSED;
++	fputs("(1) PASS\n", stderr);
++
++	///////////////////////////////////////////////////////////////
++	fputs("(2) foreign exception, exception_cleanup present\n", stderr);
++	try
++	{
++		global_e.exception_class = 0;
++		global_e.exception_cleanup = test2_exception_cleanup;
++		__real__Unwind_RaiseException(&global_e);
++	}
++	catch (...)
++	{
++	}
++	fprintf(stderr, "(2) %s\n", test_status_str[test2_status]);
++
++	///////////////////////////////////////////////////////////////
++	fputs("(3) C++ exception in foreign environment\n", stderr);
++	int counter_expected;
++	try
++	{
++		// throw was rigged such that the runtime treats C++ exceptions
++		// as foreign ones
++		throw test3_exception();
++	}
++	catch (test3_exception&)
++	{
++		fputs("(3) ERROR: wrong catch\n", stderr);
++		test3_status = FAILED;
++	}
++	catch (...)
++	{
++		fputs("(3) catch(...)\n", stderr);
++		counter_expected = test3_exception::counter + 1;
++		// one more dtor immediately after we leave catch
++	}
++	if (test3_status == PENDING && test3_exception::counter != counter_expected) {
++		fputs("(3) ERROR: exception dtor didn't run\n", stderr);
++		test3_status = FAILED;
++	}
++	if (test3_status == PENDING)
++		test3_status = PASSED;
++	fprintf(stderr, "(3) %s\n", test_status_str[test3_status]);
++
++	///////////////////////////////////////////////////////////////
++	if (test1_status == PASSED && test2_status == PASSED && test3_status == PASSED)
++		return EXIT_SUCCESS;
++	else
++		return EXIT_FAILURE;
++}
diff --git a/devel/libcxxrt/pkg-descr b/devel/libcxxrt/pkg-descr
index 5a746d4c11b5..7535b61f7890 100644
--- a/devel/libcxxrt/pkg-descr
+++ b/devel/libcxxrt/pkg-descr
@@ -1,6 +1,6 @@
 This library implements the Code Sourcery C++ ABI, as documented here:
 
-http://www.codesourcery.com/public/cxx-abi/abi.html
+WWW: http://www.codesourcery.com/public/cxx-abi/abi.html
 
 It is intended to sit below an STL implementation, and provide features required
 by the compiler for implementation of the C++ language.