鏈接fortran和c的undefined reference to問題

• c文件

#include<stdio.h>

void show_(float *);

int main(){
    float a=100;
    show_(&a);
}

• f90文件

subroutine show(a)
     real :: a
     print*, a
     return
end subroutine show

• Makefile

test : test.c show.f90
	gfortran -c show.f90 -o show.o
	gcc -c test.c -o test.o
	gcc -o test.exe test.o show.o

結果報錯

show.o:show.f90:(.text+0x3f): undefined reference to `_gfortran_st_write'
show.o:show.f90:(.text+0x58): undefined reference to `_gfortran_transfer_real_write'
show.o:show.f90:(.text+0x64): undefined reference to `_gfortran_st_write_done'

網上查到是少了靜態鏈接庫，查到的那個博客加了一大堆庫，大概用不到那麼多吧。看報錯，少的大概是gfortran庫?不管了試試看

• Makefile (-lgfortran似乎只能放在.o文件後面，否則還是報前面一樣的錯誤)

test : test.c show.f90
	gfortran -c show.f90 -o show.o
	gcc -c test.c -o test.o
	gcc -o test.exe test.o show.o -lgfortran

又報新的錯誤

C:/MyProgram/MinGW/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/libgfortran.a(write.o):(.text$get_precision+0x160): undefined reference to `quadmath_snprintf'
C:/MyProgram/MinGW/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/libgfortran.a(write.o):(.text$get_float_string+0x16b): undefined reference to `quadmath_snprintf'
C:/MyProgram/MinGW/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/libgfortran.a(write.o):(.text$get_float_string+0xa2f): undefined reference to `quadmath_snprintf'
C:/MyProgram/MinGW/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/libgfortran.a(write.o):(.text$get_float_string+0x162c): undefined reference to `quadmath_snprintf'
C:/MyProgram/MinGW/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/libgfortran.a(write.o):(.text$get_float_string+0x170a): undefined reference to `quadmath_snprintf'

我似乎發現了某種規律

• Makefile

test : test.c show.f90
	gfortran -c show.f90 -o show.o
	gcc -c test.c -o test.o
	gcc -o test.exe test.o show.o -lgfortran -lquadmath

ok，編譯通過。所以是不是看報錯加庫就可以了呢，待以後驗證吧