Merge pull request #2 from RT-Thread/master

update from official source

5 files changed, 131 insertions, 0 deletions

diff --git a/components/cplusplus/README.md b/components/cplusplus/README.md
new file mode 100644
index 0000000000..44851db56b
--- /dev/null
+++ b/components/cplusplus/README.md
@@ -0,0 +1,53 @@
+# C++ support for RT-Thread #
+
+This is the C++ component in RT-Thread RTOS. In order to support C++ language, this component
+implement a basic environment, such as new/delete operators.
+
+Because RT-Thread RTOS is used in embedded system mostly, there are some rules for C++ applications:
+1. DOES NOT use exception.
+2. DOES NOT use Run-Time Type Information (RTTI).
+3. Template is discouraged and it easily causes code text large.
+4. Static class variables are discouraged. The time and place to call their constructor function could not be precisely controlled and make multi-threaded programming a nightmare.
+5. Multiple inheritance is strongly discouraged, as it can cause intolerable confusion.
+
+*NOTE*: The libc must be enable.
+
+About GNU GCC compiler
+
+please add following string in your ld link script:
+// in your .text section
+        PROVIDE(__ctors_start__ = .);
+        /* old GCC version uses .ctors */
+        KEEP(*(SORT(.ctors.*)))
+        KEEP(*(.ctors))
+        /* new GCC version uses .init_array */
+        KEEP (*(SORT(.init_array.*)))
+        KEEP (*(.init_array))
+        PROVIDE(__ctors_end__ = .);
+
+        . = ALIGN(4);
+
+// as a standalone section if you use ARM target.
+
+    /* The .ARM.exidx section is used for C++ exception handling. */
+    /* .ARM.exidx is sorted, so has to go in its own output section.  */
+    __exidx_start = .;
+    .ARM.exidx :
+    {
+        *(.ARM.exidx* .gnu.linkonce.armexidx.*)
+
+        /* This is used by the startup in order to initialize the .data secion */
+        _sidata = .;
+    } > CODE
+    __exidx_end = .;
+
+    /* .data section which is used for initialized data */
+
+// in your .data section
+        PROVIDE(__dtors_start__ = .);
+        KEEP(*(SORT(.dtors.*)))
+        KEEP(*(.dtors))
+        PROVIDE(__dtors_end__ = .);
+
+        . = ALIGN(4);
+
diff --git a/components/cplusplus/SConscript b/components/cplusplus/SConscript
new file mode 100644
index 0000000000..b41537a52b
--- /dev/null
+++ b/components/cplusplus/SConscript
@@ -0,0 +1,11 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd = GetCurrentDir()
+src = Glob('*.cpp') + Glob('*.c')
+CPPPATH = [cwd]
+
+group = DefineGroup('CPlusPlus', src, depend = ['RT_USING_CPLUSPLUS', 'RT_USING_LIBC'], CPPPATH = CPPPATH)
+
+Return('group')
diff --git a/components/cplusplus/crt.cpp b/components/cplusplus/crt.cpp
new file mode 100644
index 0000000000..6fa540b9e7
--- /dev/null
+++ b/components/cplusplus/crt.cpp
@@ -0,0 +1,27 @@
+#include <rtthread.h>
+#include "crt.h"
+
+void *operator new(size_t size)
+{
+    return rt_malloc(size);
+}
+
+void *operator new[](size_t size)
+{
+    return rt_malloc(size);
+}
+
+void operator delete(void *ptr)
+{
+    rt_free(ptr);
+}
+
+void operator delete[] (void *ptr)
+{
+    return rt_free(ptr);
+}
+
+void __cxa_pure_virtual(void)
+{
+    rt_kprintf("Illegal to call a pure virtual function.\n");
+}
diff --git a/components/cplusplus/crt.h b/components/cplusplus/crt.h
new file mode 100644
index 0000000000..fd287c2ad5
--- /dev/null
+++ b/components/cplusplus/crt.h
@@ -0,0 +1,16 @@
+#ifndef CRT_H_
+#define CRT_H_
+
+#include <inttypes.h>
+#include <stdlib.h>
+
+void *operator new(size_t size);
+void *operator new[](size_t size);
+
+void operator delete(void * ptr);
+void operator delete[] (void *ptr);
+
+extern "C" void __cxa_pure_virtual(void);
+extern "C" int  cplusplus_system_init(void);
+
+#endif
diff --git a/components/cplusplus/crt_init.c b/components/cplusplus/crt_init.c
new file mode 100644
index 0000000000..20f81cdb54
--- /dev/null
+++ b/components/cplusplus/crt_init.c
@@ -0,0 +1,24 @@
+#include <rtthread.h>
+
+int cplusplus_system_init(void)
+{
+#if defined(__GNUC__) && !defined(__CC_ARM)
+    extern unsigned char __ctors_start__;
+    extern unsigned char __ctors_end__;
+    typedef void (*func)(void);
+
+    /* .ctors initalization */
+    func *ctors_func;
+
+    for (ctors_func = (func *)&__ctors_start__;
+         ctors_func < (func *)&__ctors_end__;
+         ctors_func ++)
+    {
+        (*ctors_func)();
+    }
+#endif
+
+    return 0;
+}
+INIT_COMPONENT_EXPORT(cplusplus_system_init);
+