STM32: libstdc++ tweaks. Code size reduced to 61k (release, -Os, LTO) with no functional changes. Shall be refactored later.

libuavcan_drivers/stm32/test_stm32f107/Makefile

@@ -43,6 +43,8 @@ SERIAL_CLI_PORT_NUMBER = 2
 
 RELEASE_OPT = -Os -fomit-frame-pointer
 DEBUG_OPT = -Os -g3
-#USE_OPT = -flto -u_port_lock -u_port_unlock -uchThdExit
+USE_OPT = -flto -u_port_lock -u_port_unlock -u_exit -u_kill -u_getpid -uchThdExit
+USE_OPT += -fno-unwind-tables -fno-stack-protector
+USE_CPPOPT = -fno-threadsafe-statics
 
 include crdr_chibios/rules_stm32f105_107.mk

libuavcan_drivers/stm32/test_stm32f107/src/dummy.cpp

@@ -3,6 +3,7 @@
  */
 
 #include <cstdlib>
+#include <sys/types.h>
 
 /*
  * stdlibc++ workaround.
@@ -48,3 +49,87 @@ void __throw_future_error(int) { std::abort(); }
 void __throw_bad_function_call() { std::abort(); }
 
 }
+
+/*
+ * The default pulls in 70K of garbage
+ */
+namespace __gnu_cxx
+{
+
+void __verbose_terminate_handler()
+{
+    std::abort();
+}
+
+}
+
+__extension__ typedef int __guard __attribute__((mode (__DI__)));
+
+extern "C" void __cxa_atexit(void(*)(void *), void*, void*) { }
+
+extern "C" int __aeabi_atexit(void*, void(*)(void*), void*)
+{
+    return 0;
+}
+
+extern "C" int __cxa_guard_acquire(__guard* g) { return !*(char*)(g); }
+extern "C" void __cxa_guard_release (__guard* g) { *(char *)g = 1; }
+extern "C" void __cxa_guard_abort (__guard*) { }
+
+/*
+ * The default pulls in about 12K of garbage
+ */
+extern "C" void __cxa_pure_virtual()
+{
+    std::abort();
+}
+
+
+void* operator new(size_t)
+{
+    std::abort();
+    return reinterpret_cast<void*>(0xFFFFFFFF);
+}
+
+void* operator new[](size_t)
+{
+    std::abort();
+    return reinterpret_cast<void*>(0xFFFFFFFF);
+}
+
+void operator delete(void*)
+{
+    std::abort();
+}
+
+void operator delete[](void*)
+{
+    std::abort();
+}
+
+/*
+ * sbrk function for getting space for malloc and friends
+ */
+extern "C"
+{
+
+extern int _end;
+
+caddr_t _sbrk(int incr)
+{
+    static unsigned char *heap = NULL;
+    unsigned char *prev_heap;
+
+    if (heap == NULL)
+    {
+        heap = (unsigned char *) &_end;
+    }
+    prev_heap = heap;
+    /* check removed to show basic approach */
+
+    heap += incr;
+
+    return (caddr_t) prev_heap;
+}
+
+}