libvpx库的yasm编译如何生成-fPIC位置无关代码？

jaryyy2000

我在编译时需要连接libvpx静态库，提示我需要使用-fPIC参数重新编译位置无关的libvpx库

1. /usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../../lib/libvpx.a(subpixel_mmx.asm.o): relocation R_X86_64_PC32 against symbol `vp8_bilinear_filters_x86_8' can not be used when making a shared object; recompile with -fPIC
   
2. /usr/bin/ld: final link failed: Bad value
   
3. collect2: error: ld returned 1 exit status
   
4. Makefile:518: recipe for target 'libgd.la' failed
   
5. make[2]: *** [libgd.la] Error 1
   
6. make[2]: Leaving directory '/root/libgd/libgd-2.1.1/src'
   
7. Makefile:436: recipe for target 'all' failed
   
8. make[1]: *** [all] Error 2
   
9. make[1]: Leaving directory '/root/libgd/libgd-2.1.1/src'
   
10. Makefile:331: recipe for target 'all-recursive' failed
    
11. make: *** [all-recursive] Error 1
    

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然后我去修改libvpx的Makefile，在CFLAGS和CXXFLAGS还有ASFLAGS里面添加了-fPIC参数:

1. CFLAGS+=-I$(BUILD_PFX)$(BUILD_ROOT) -I$(SRC_PATH) -fPIC
   
2. CXXFLAGS+=-I$(BUILD_PFX)$(BUILD_ROOT) -I$(SRC_PATH) -fPIC
   
3. ASFLAGS+=-I$(BUILD_PFX)$(BUILD_ROOT)/ -I$(SRC_PATH)/ -fPIC/
   

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编译以后，就会报错，如下：

1.     [AS] vpx_ports/emms.asm.o
   
2. yasm: FATAL: unrecognized object format `PIC/'
   
3. Makefile:179: recipe for target 'vpx_ports/emms.asm.o' failed
   
4. make[1]: *** [vpx_ports/emms.asm.o] Error 1
   
5. Makefile:17: recipe for target '.DEFAULT' failed
   
6. make: *** [.DEFAULT] Error 2
   

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如果去掉ASFLAGS的-fPIC参数，前面链接的时候就会提示
/libvpx.a(subpixel_mmx.asm.o): relocation R_X86_64_PC32 against symbol `vp8_bilinear_filters_x86_8' can not be used when making a shared object; recompile with -fPIC

yasm如何编译位置无关的代码？

yjh777

http://ffmpeg.org/pipermail/ffmp ... ovember/076635.html

-DPIC