Compiler Restrictions

Certain optimizations that might be performed by compilers compiling native methods can cause the VM to fail. The VM relies on the ability to examine the stack frames of functions on a thread's stack. Therefore, the code for native functions must always create stack frames as specified in the system calling conventions for non-leaf functions. Additionally, the frame pointer register must always point to a valid stack frame.

• On the Intel (IA) platform, the Sun Workshop^TM C compiler can generate code that violates this requirement at optimization levels -xO4 and -xO5. You should not use an optimization level above -xO3.

• On the SPARC platform, all optimization levels are safe. If you are using another compiler, check its documentation to ensure that it produces code that meets this requirement.

A native method that violates this restriction can cause the VM to abort randomly.