Compatibility with LLVM libunwind

repos/base/src/ld/genode.ld

@@ -51,6 +51,8 @@ SECTIONS
 	__ex_table : { *(__ex_table) }
 
 	.eh_frame_hdr : { *(.eh_frame_hdr) }
+	__eh_frame_hdr_start = SIZEOF(.eh_frame_hdr) > 0 ? ADDR(.eh_frame_hdr) : 0;
+	__eh_frame_hdr_end = SIZEOF(.eh_frame_hdr) > 0 ? . : 0;
 
 	. = ALIGN(0x1000);
 
@@ -91,7 +93,9 @@ SECTIONS
 	/* exception frames for C++ */
 	.eh_frame : {
 		__eh_frame_start__ = .;
+		__eh_frame_start = .;
 		KEEP (*(.eh_frame))
+		__eh_frame_end = .;
 		LONG(0)
 	} : rw
 

repos/base/src/lib/cxx/Tupfile

@@ -3,6 +3,16 @@ include_rules
 DEFINES = -ffunction-sections -fno-strict-aliasing -g -fPIC
 	# drop the standard defines to avoid -nostdinc
 
+export LIBCXX
+export LIBCXXABI
+export LIBUNWIND
+
+INCLUDES += -I$LIBCXX/include/c++/v1
+INCLUDES += -I$LIBCXXABI/include
+
+LLVM_LIBS += $LIBCXXABI/lib/libc++abi.a
+LLVM_LIBS += $LIBUNWIND/lib/libunwind.a
+
 : foreach *.cc |> !cxx |> {supc++}
 
 #
@@ -18,11 +28,7 @@ KEEP_SYMBOLS = \
 	-u _ZTVN10__cxxabiv119__pointer_type_infoE \
 	-u _ZTSN10__cxxabiv120__function_type_infoE \
 
-LIBCXX_GCC = \
-	`$(CXX) $(CC_MARCH) -print-file-name=libsupc++.a` \
-	`$(CXX) $(CC_MARCH) -print-file-name=libgcc_eh.a` \
-
-: {supc++} |> $(LD) $(LD_MARCH) $(KEEP_SYMBOLS) -r %f $(LIBCXX_GCC) -o %o |> supc++.tmp
+: {supc++} |> $(LD) $(LD_MARCH) $(KEEP_SYMBOLS) -r %f $(LLVM_LIBS) -o %o |> supc++.tmp
 
 #
 # Here we define all symbols we want to hide in libsupc++ and libgcc_eh
@@ -63,7 +69,8 @@ EH_SYMBOLS += \
 
 REDEF_SYMBOLS = `echo $(EH_SYMBOLS) | awk -v RS=' ' '{ print "--redefine-sym "$1"=_cxx_"$1 }'`
 
-: supc++.tmp |> $(OBJCOPY) $(LOCAL_SYMBOLS) $(REDEF_SYMBOLS) %f %o |> supc++.o {obj}
+export OBJCOPY
+: supc++.tmp |> $OBJCOPY $(LOCAL_SYMBOLS) $(REDEF_SYMBOLS) %f %o |> supc++.o {obj}
 
 : foreach *.c |> !cc |> {obj}
 

repos/base/src/lib/cxx/malloc_free.cc

@@ -66,8 +66,14 @@ typedef unsigned long Block_header;
 
 extern "C" void *malloc(size_t size)
 {
-	/* enforce size to be a multiple of 4 bytes */
-	size = (size + 3) & ~3;
+	/*
+	 * Use a double-word aligned allocations as required by the Itanium C++ ABI.
+	 *
+	 * See https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html#base-data
+	 */
+
+	constexpr size_t align_mask = sizeof(long)*2 - 1;
+	size = (size + align_mask) & ~align_mask;
 
 	/*
 	 * We store the size of the allocation at the very
@@ -75,13 +81,21 @@ extern "C" void *malloc(size_t size)
 	 * the subsequent address. This way, we can retrieve
 	 * the size information when freeing the block.
 	 */
-	unsigned long real_size = size + sizeof(Block_header);
+	unsigned long real_size = size + sizeof(Block_header)*2;
 	void *addr = 0;
 	if (!cxx_heap().alloc(real_size, &addr))
 		return 0;
 
 	*(Block_header *)addr = real_size;
-	return (Block_header *)addr + 1;
+
+	return (Block_header *)addr + 2;
+}
+
+
+extern "C" int posix_memalign(void **dest, size_t /*align*/, size_t size)
+{
+	*dest = malloc(size);
+	return *dest ? 0 : 1;
 }
 
 
@@ -97,7 +111,7 @@ extern "C" void free(void *ptr)
 {
 	if (!ptr) return;
 
-	unsigned long *addr = ((unsigned long *)ptr) - 1;
+	unsigned long *addr = ((unsigned long *)ptr) - 2;
 	cxx_heap().free(addr, *addr);
 }
 
@@ -113,7 +127,7 @@ extern "C" void *realloc(void *ptr, Genode::size_t size)
 	}
 
 	/* determine size of old block content (without header) */
-	unsigned long old_size = *((Block_header *)ptr - 1)
+	unsigned long old_size = *((Block_header *)ptr - 2)
 	                         - sizeof(Block_header);
 
 	/* do not reallocate if new size is less than the current size */

repos/base/src/lib/cxx/misc.cc

@@ -62,9 +62,9 @@ extern "C" int __cxa_atexit(void(*func)(void*), void *arg,
 extern int genode___cxa_finalize(void *dso);
 
 
-extern "C" void __cxa_finalize(void *dso)
+extern "C" int __cxa_finalize(void *dso)
 {
-	genode___cxa_finalize(dso);
+	return genode___cxa_finalize(dso);
 }
 
 
@@ -127,6 +127,17 @@ extern "C" void abort(void)
 }
 
 
+extern "C" int fflush(void*) {
+	return 0;
+}
+
+
+extern "C" int fprintf(void*, const char *msg, ...) {
+	Genode::warning("C++ runtime: ", msg);
+	return 0;
+}
+
+
 extern "C" int fputc(int, void*) {
 	return 0;
 }
@@ -215,6 +226,12 @@ extern "C" int strcmp(const char *s1, const char *s2)
 }
 
 
+extern "C" char *getenv(const char *)
+{
+	return NULL;
+}
+
+
 /*
  * Needed by ARM EABI (gcc-4.4 Codesourcery release1039)
  */
@@ -225,6 +242,42 @@ extern "C" int sprintf(char *, const char *, ...)
 }
 
 
+/*
+ * Needed by Clang/Libunwind/Libc++abi
+ */
+
+extern "C" {
+
+
+void __assert(const char *, const char *, int, const char *) {
+	std::terminate();
+}
+
+int tolower(int c) { return c; }
+int isdigit(int) { return 0; }
+int isxdigit(int) { return 0; }
+int islower(int) { return 0; }
+
+
+int snprintf(char *, size_t, const char *, ...) { return 0; }
+
+int vfprintf(FILE *, const char *msg, va_list)
+{
+	Genode::warning("C++ runtime: ", msg);
+	return 0;
+}
+
+struct Dl_info;
+int dladdr(const void *, Dl_info *) { return 0; }
+
+struct pthread_rwlock_t;
+int pthread_rwlock_rdlock(pthread_rwlock_t *) { return 0; }
+int pthread_rwlock_unlock(pthread_rwlock_t *) { return 0; }
+int pthread_rwlock_wrlock(pthread_rwlock_t *) { return 0; }
+
+}
+
+
 /**********************************
  ** Support for stack protection **
  **********************************/

repos/base/src/lib/cxx/new_delete.cc

@@ -67,7 +67,7 @@ void operator delete (void *ptr, Deallocator &dealloc) { try_dealloc(ptr,  deall
  * implementation of the 'stdcxx' library instead. To make this possible, the
  * 'delete (void *)' implementation in the 'cxx' library must be 'weak'.
  */
-__attribute__((weak)) void operator delete (void *)
+__attribute__((weak)) void operator delete (void *) noexcept
 {
 	Genode::error("cxx: operator delete (void *) called - not implemented. "
 	              "A working implementation is available in the 'stdcxx' library.");