What is the benefit of having 2 sections – .data and .bss for process scope variables. Why not just have one? I know what each section is used for. I am using gcc.
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What is the benefit of having 2 sections – .data and .bss for process scope variables. Why not just have one? I know what each section is used for. I am using gcc.
.bss consumes “memory” but not space within the executable file. Its sole purpose is to hold zero-initialized data (as you know).
.data (and related sections such as rodata) do actually consume space within the executable file, and usually holds strings, integers, and perhaps even entire objects.
There is a lot of zero-initialized data in a typical program, so having that data not consume extra space in the output file is a significant bonus.
As for the multiple .*data sections… .rodata/.data can be used as a hint for memory protection (disallow overwriting .rodata, allow read/write to .data).