Msg/ClobberedSP

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Revision as of 23:25, 9 March 2019 by Henry (talk | contribs) (→‎Nios II)

A function should always ensure that the stack pointer is the same at the entry and exit of the function. This message tells you that this didn't happen: the stack pointer was different at the function return than when the function was first called.

Examples

ARMv7

.global _start
_start:
    mov sp, #0x1000		// Initialize SP to something sane
    bl MyFunction
    nop
    nop
    # ...
    
MyFunction:
    push {r4}	// Change SP
    bx lr		// SP is different at return

Nios II

.global _start
_start:
    movi sp, 0x1000		# Initialize SP
    call Function
    nop
    nop
    
Function:
    subi sp, sp, 4		# Modify SP
    ret					# SP is different at return

Disabling this message

This debugging check can be disabled in the Debugging Checks section of the Settings box: Function clobbered ra or sp.