Precise Interprocedural Analysis in the Presence of Pointers to the Stack

In a language with procedures and pointers as parameters, an instruction can modify memory locations anywhere in the call-stack. The presence of such side effects breaks most generic interprocedural analysis methods, which assume that only the top of the stack may be modified. We present a method that addresses this issue, based on the definition of an equivalent local semantics in which writing through pointers has a local effect on the stack. Our second contribution in this context is an adequate representation of summary functions that models the effect of a procedure, not only on the values of its scalar and pointer variables, but also on the values contained in pointed memory locations. Our implementation in the interprocedural analyser PInterproc results in a verification tool that infers relational properties on the value of Boolean, numerical and pointer variables