On 2011/12/17 06:21 AM, Richard Henderson wrote: > On 12/16/2011 03:16 AM, Chung-Lin Tang wrote: >> Hi, under powerpc targets, using -mrelocatable under some cases triggers >> an error during final assembly generation: rs6000_assemble_integer() >> calls varasm.c:unlikely_text_section_p(), and the call chain eventually >> gets to where the section htab is queried for ".text.unlikely", and >> fails because of mismatched section flags: "error: foo causes a section >> type conflict" >> >> This seems to happen after rev.167085, 4.6 branch is also affected. >> >> The flag mismatch seems quite straightforward: current_function_decl is >> passed in as the decl here, and as it's final assembly now, it is >> NULL_TREE. varasm.c:default_section_type_flags() adds SECTION_WRITE to >> its return value, and things get borked. > > I don't understand what was put into .text.unlikely that was not a > function in the first place? Did we try to put data there somewhere?
I don't think it's that kind of problem; the powerpc backend uses unlikely_text_section_p(), which compares the passed in argument section and the value of function_section_1(current_function_decl,true). Since current_function_decl is NULL at assembly phase, it retrieves ".text.unlikely" to test for equality. It's the retrieving/lookup that fails here, because the default looked-up section flags set when decl == NULL does not really seem to make sense (adds SECTION_WRITE). Chung-Lin
