The dynamic library "libuser.so" depends on libdfclib.so

the dependency relationship can be figured out at Compilation or Runtime.

ldd dynamic_library_test/lib/libuser.so
    linux-vdso.so.1 =>  (0x00007fff065eb000)
    libstdc++.so.6 => /opt/Apps/local/gcc-5.3.0/lib64/libstdc++.so.6 (0x00007f585e3c2000)
    libm.so.6 => /lib64/libm.so.6 (0x00007f585e0a9000)
    libgcc_s.so.1 => /opt/Apps/local/gcc-5.3.0/lib64/libgcc_s.so.1 (0x00007f585de93000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f585dad0000)
    /lib64/ld-linux-x86-64.so.2 (0x000055c5a0db4000)

ldd dynamic_library_test_2/lib/libuser.so
    linux-vdso.so.1 =>  (0x00007ffce1073000)
    libdfclib.so => not found
    libstdc++.so.6 => /opt/Apps/local/gcc-5.3.0/lib64/libstdc++.so.6 (0x00007fb976775000)
    libm.so.6 => /lib64/libm.so.6 (0x00007fb976473000)
    libgcc_s.so.1 => /opt/Apps/local/gcc-5.3.0/lib64/libgcc_s.so.1 (0x00007fb97625d000)
    libc.so.6 => /lib64/libc.so.6 (0x00007fb975e99000)
    /lib64/ld-linux-x86-64.so.2 (0x000055f9b67ed000)

Author: wintel2014

Linux/LibraryComiple/dynamic_library_test/Makefile

@@ -0,0 +1,12 @@
+main:main.cpp
+	make -C src/
+	make -C lib/
+	g++ $^ -Llib -Iinclude -luser -ldfclib -o $@
+
+clean:
+	rm main
+	make -C src/ clean
+	make -C lib/ clean
+
+run:
+	export LD_LIBRARY_PATH=lib; ./main

Linux/LibraryComiple/dynamic_library_test/include/dfclib.h

@@ -0,0 +1,6 @@
+#pragma once
+class DFCFuncProvider
+{
+public:
+    double sum(double a, double b);
+};

Linux/LibraryComiple/dynamic_library_test/include/user.h

@@ -0,0 +1,2 @@
+#include <dfclib.h>
+double calc (DFCFuncProvider* obj, double var);

Linux/LibraryComiple/dynamic_library_test/lib/Makefile

@@ -0,0 +1,7 @@
+DEP = $$(gcc -MM -I../include  dfclib.cpp | gawk '{print $2" "$3}')
+libdfclib.so: dfclib.cpp
+	#echo $$(gcc -MM -I../include  dfclib.cpp | gawk '{print $2" "$3}')
+	g++ $^  -I../include --shared -fPIC -o $@
+
+clean:
+	rm libdfclib.so 

Linux/LibraryComiple/dynamic_library_test/lib/dfclib.cpp

@@ -0,0 +1,5 @@
+#include <dfclib.h>
+double DFCFuncProvider::sum(double a, double b)
+{
+    return a+b;
+}

Linux/LibraryComiple/dynamic_library_test/main.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+#include <user.h>
+#include <dfclib.h>
+
+int main()
+{
+    DFCFuncProvider Obj;
+
+    double a = 2.0; 
+    
+    std::cout<<calc(&Obj, a)<<std::endl;
+}

Linux/LibraryComiple/dynamic_library_test/src/Makefile

@@ -0,0 +1,5 @@
+libuser.so:user.cpp 
+	g++ -g3 $^  -I../include --shared -fPIC -o ../lib/$@
+
+clean:
+	rm ../lib/libuser.so

Linux/LibraryComiple/dynamic_library_test/src/user.cpp

@@ -0,0 +1,6 @@
+#include <dfclib.h>
+double calc (DFCFuncProvider* obj, double var)
+{
+    return obj->sum(1.1,var);
+}
+

Linux/LibraryComiple/dynamic_library_test_2/Makefile

@@ -0,0 +1,12 @@
+main:main.cpp
+	make -C src/
+	make -C lib/
+	g++ $^ -Llib -Iinclude -luser -o $@
+
+clean:
+	rm main
+	make -C src/ clean
+	make -C lib/ clean
+
+run:
+	export LD_LIBRARY_PATH=lib; ./main

Linux/LibraryComiple/dynamic_library_test_2/include/dfclib.h

@@ -0,0 +1,6 @@
+#pragma once
+class DFCFuncProvider
+{
+public:
+    double sum(double a, double b);
+};

Linux/LibraryComiple/dynamic_library_test_2/include/user.h

@@ -0,0 +1,2 @@
+#include <dfclib.h>
+double calc (DFCFuncProvider* obj, double var);

Linux/LibraryComiple/dynamic_library_test_2/lib/Makefile

@@ -0,0 +1,7 @@
+DEP = $$(gcc -MM -I../include  dfclib.cpp | gawk '{print $2" "$3}')
+libdfclib.so: dfclib.cpp
+	#echo $$(gcc -MM -I../include  dfclib.cpp | gawk '{print $2" "$3}')
+	g++ $^  -I../include --shared -fPIC -o $@
+
+clean:
+	rm libdfclib.so 

Linux/LibraryComiple/dynamic_library_test_2/lib/dfclib.cpp

@@ -0,0 +1,5 @@
+#include <dfclib.h>
+double DFCFuncProvider::sum(double a, double b)
+{
+    return a+b;
+}

Linux/LibraryComiple/dynamic_library_test_2/main.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+#include <user.h>
+#include <dfclib.h>
+
+int main()
+{
+    DFCFuncProvider Obj;
+
+    double a = 2.0; 
+    
+    std::cout<<calc(&Obj, a)<<std::endl;
+}

Linux/LibraryComiple/dynamic_library_test_2/src/Makefile

@@ -0,0 +1,5 @@
+libuser.so:user.cpp 
+	g++ -g3 $^  -I../include --shared -fPIC -o ../lib/$@ -L../lib -ldfclib
+
+clean:
+	rm ../lib/libuser.so

Linux/LibraryComiple/dynamic_library_test_2/src/user.cpp

@@ -0,0 +1,6 @@
+#include <dfclib.h>
+double calc (DFCFuncProvider* obj, double var)
+{
+    return obj->sum(1.1,var);
+}
+