Assembler warning with gcc warning when placing data in .text

user_1084774 0
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When I compile

__attribute__((section(".text"))) const int x = 42;
int main(){ return x; }

with gcc (works with tinycc and clang), I get

Warning: ignoring changed section attributes for .text.

What is the cause of the warning and how can it be eliminated while still keeping the (always readonly) data in .text?

assembly gcc c
2 Answers

Apparently:

__attribute__((section(".text#"))) const int x = 42;

Ref: https://gcc.gnu.org/ml/gcc-help/2010-09/msg00088.html where the answerer explains:

__attribute__ ((section(".text"))) will make gcc emits ,"aw",@progbits after the .text to alter the section attributes. If you use: __attribute__ ((section(".text#"))) (notice the extra '#') this suffix will be commented in the assembly and the warning will disappear

In that case the variable concerned was not const, so it was especially ill-advised (as stated by another responder) to the same question. In your case it is a const, so the access is "a" rather than "aw" - still probably ill-advised however.

user_1689860

Apparently gcc emits a .section .text,"a",@progbits directive instead of just .section .text. I don't see any way to avoid it. However the default linker script usually merges all sections named .text.* so you can do something like __attribute__((section(".text.consts"))) and in the final binary it will be in the .text section.

@Clifford found a hackish workaround which involves putting a # after the section name so that the assembler considers the rest of the line a comment.

user_5479810
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