4.2.9 Stack Guidance

Available with a PRO compiler license, the compiler's stack guidance feature can be used to estimate the maximum depth of any stack used by a program.

Runtime stack overflows cause program failure and can be difficult to track down, especially when the program is complex and interrupts are being used. The compiler's stack guidance feature constructs and analyzes the call graph of a program, determines the stack usage of each function, and produces a report, from which the depth of stacks used by the program can be inferred. Monitoring a program's stack usage during its development will mitigate the possibility of stack overflow situations.

This feature is enabled by the -mchp-stack-usage command-line option.

Once enabled, the operation of the stack guidance feature is fully automatic. For command-line execution of the compiler, a report will be displayed directly to the console after a successful build. When building in the MPLAB X IDE, this same report will be displayed in the build view in the Output window.

A more detailed and permanent record of the stack usage information will be available in the map file, should one be requested using the -Wl,-Map=mapfile command-line option or the equivalent control in the MPLAB X IDE project properties.