symbian rodata overlap errors

 

程序代码过大也会导致程序无法正常进入，具体执行时报错“功能表：此功能不被支持”。用S603rdMR编译双城的时候，被这个错误折腾了半宿。后来仔细看编译输出，发现编译时，GCCE已经作了警告：
arm-none-symbianelf-ld: section .rodata [0038d050 -> 0049005f] overlaps 
section .data [00400000 -> 004051a5]
arm-none-symbianelf-ld: section .bss [004051a6 -> 004051a7] overlaps section 
.rodata [0038d050 -> 0049005f]。
查询网上资料:
Your code size (.rodata) is too large so it overlaps the hard coded .data section begining at 0x400000.

I've changed these hard coded .data section in /epoc32/tools/cl_bpabi.pm line 793 & 799 :

"/$(CODE_SEGMENT_START) ", "/$(DATA_SEGMENT_START) 0x400000 ", "/$(SYMVER_OPTION) ","/$(SO_NAME_OPTION) ","$LinkAs"

I replaced 0x400000 by 0xA00000 and I get my app properly linked linked, and it works fine on phone.
我改了以后好像没什么用，看到这个：For UREL static solution everything is fine as the size is much more less then 4mb, but for UDEB (to be able to debug on hardware) the size goes beyond...
和我情况一样，我也是编译gcce udeb才不成功
然后我改MMP文件：
EPOCSTACKSIZE                           0x10000
EPOCHEAPSIZE                             0x100000 0x4000000
变为
EPOCSTACKSIZE                           0x100000
EPOCHEAPSIZE                             0x100000 0x4000000
再编译，搞定
 
补充：
 
我按照上面的方法，将heap最大值改成4M，重新链接，发现还是有同样的错误。再到/epoc32/tools/cl_bpabi.pm，将0x400000改成0xA00000，再编译链接，这次就真的搞定了。不知道是不是要两处都改才行。没有再去试不改heap大小能否链接成功了。各位有兴趣的话可以自己去试试。o(∩_∩)o
 
针对该问题具体解决方案有二：

A 优化代码，减小体积。可以在MMP中加入下面一行提示编译器进行优化：
OPTION GCCE -O2 -fno-unit-at-a-time
据说在FP1及之后的版本已经默认该选项了。
B 改变进程起始地址。具体修改Epoc32/tools/cl_bpabi.pm第792行和799行，将0x400000改为0xA00000。也可以只改工程相关的设置，在MMP中加入：
EPOCDATALINKADDRESS 0x005f0000