Am 05.05.26 um 19:05 schrieb Richard Biener:
On Tue, May 5, 2026 at 5:41 PM Georg-Johann Lay via Gcc <[email protected]> wrote:
In the avr backend there is a static variable avr_no_call_main_p that
is set in TARGET_INSERT_ATTRIBUTES and used in TARGET_ASM_FILE_END.
This works as expected in non-LTO compilations, with LTO however,
TARGET_INSERT_ATTRIBUTES runs in cc1[plus] but TARGET_ASM_FILE_END
is run by lto1, hence the variable is not set as expected.
What's the recommended way to handle such a situation?
Without looking too closely I assume there's an actual attribute somewhere
(on the main function decl?). Instead of using a global variable you'd
check for the presence of the attribute. Now - the question is whether
the TARGET_ASM_FILE_END behavior is only required in the TU with
the main() definition? In that case this should work.
What works is to attach a new attribute to main when the conditions are
right, then check for that attribute in, say,
TARGET_DECLARE_FUNCTION_NAME and set a variable accordingly, and then
check for that var in TARGET_ASM_FILE_END.
What's a bit ugly is that it requires a new target attribute that's only
for internal usage and should not to be set by the user. Maybe not
document it is okay then.
Is there some policy for such internal-use-only function attributes?
Johann
I see you emit a special symbol conditional so what you can also do is
create that as a global variable in the symbol table and rely on the middle-end
to output it.
