Vasanth <[EMAIL PROTECTED]> writes: > What is the recommended way to do DW2 frame unwinding based exception > handling for targets that do not support unaligned accesses in > hardware? I did see the documentation about UNALIGNED_INT_ASM_OP, but > not sure if that is meant to generate a directive to the assembler to > produce an aligned int (the name indicates otherwise). Also, I see > UNALIGNED_INT_ASM_OP being used only in the VMS debugging source file. > So I am unsure how it relates to DW2 based frame unwinding.
UNALIGNED_INT_ASM_OP tells the assembler to not do any automatic alignment before emitting the value. In current development sources this is TARGET_ASM_UNALIGNED_SI_OP, and it is defined in a number of config/*/*.c files. It should not matter that your target does not support unaligned access in hardware. The code in read_encoded_value_with_base in unwind-pe.h should do the right thing, by using a packed union. On a target which does not support unaligned access, it will use byte reads. If you really do want to insist that all accesses be aligned, it should work to define ASM_PREFERRED_EH_DATA_FORMAT to be DW_EH_PE_aligned. Ian
