I just noticed at the top of Sections.html in gccint: The normal way of controlling a foo_section variable is to define the associated FOO_SECTION_ASM_OP macro, as described below. The macros are only read once, when varasm.c initializes itself, so their values must be run-time constants.
This sentence is quite confusing. 'their values must be run-time constants' means that it can only depend on gcc's compile time flags? Or can it depend on gcc's command line arguments (for example)? I guess what's confusing me is 'when varasm.c initializes itself'. Does this happen after gcc command line arguments are read or at gcc's compile time? Paulo Matos > -----Original Message----- > From: gcc-ow...@gcc.gnu.org [mailto:gcc-ow...@gcc.gnu.org] On Behalf Of > Paulo Matos > Sent: 23 October 2012 12:08 > To: gcc@gcc.gnu.org > Subject: Documentation problem with TEXT_SECTION_ASM_OP > > Hi, > > TEXT_SECTION_ASM_OP doc says: > "A C expression whose value is a string, including spacing, containing the > assembler operation that should precede instructions and read-only data." > > However, crtstuff.c uses `asm(TEXT_SECTION_ASM_OP)'. > > I am trying to use a C expression for TEXT_SECTION_ASM_OP like: > #define TEXT_SECTION_ASM_OP (arch == "v2" ? "\t.section .text, \"ax\"" : > "\t.section .textc, \"axz\"") > > This seems to be valid according to the docs but fails to compile crtstuff.c > since TEXT_SECTION_ASM_OP should be a string literal to be used with asm. > Since this is most likely a problem with the docs, how can I achieve something > like this and have only a string literal as value or TEXT_SECTION_ASM_OP? > > Cheers, > > Paulo Matos > > >
