Problem of using malloc() without including stdlib.h

[Jonathan Lu]

Hi core-libs-dev,

I found that for some native code of OpenJDK code base, malloc() is used 
without including header file stdlib.h, such as following files,
./src/solaris/native/sun/java2d/opengl/GLXSurfaceData.c
./src/solaris/native/sun/java2d/x11/XRBackendNative.c
....

I assume that there's no hacking tricks involved here, right? because 
this may cause problem for some C compilers, which assumes 'int' as the 
default return type of a function if it cannot find the function's 
declaration during compiling. Under such a condition, actual return 
result of type 'void*' from malloc() will be converted to 'int', which 
may result in truncated pointers in 64bit platforms. If the application 
tries to dereference such a broken pointer, error will occur.

Indeed I found some indirect includes of stdlib.h, but there're still 
some I do not see a stdlib.h get included from any of  the 
direct/indirect included headers. I think in order to fix this problem, 
two approaches may be considered here,
a) add "#include <stdlib.h>" to every missing .c file.
b) add "#include <stdlib.h>" to a commonly  referenced header file, such 
as jni_util.h. but it would not be easy to find such a file for all and 
creating one is the same as approach a).

But both methods need to change many files, any other ideas about how to 
fix it more elegantly?

Thanks and best regards!
- Jonathan