Message-ID: <19990722003428.12362.qmail@daffy.airs.com> Date: 21 Jul 1999 20:34:27 -0400 From: Ian Lance Taylor To: snowball3 AT bigfoot DOT com CC: binutils AT sourceware DOT cygnus DOT com, djgpp-workers AT delorie DOT com In-reply-to: <199907220030.AAA09334@out5.ibm.net> (snowball3@bigfoot.com) Subject: Re: DJGPP and alignment References: <199907211607 DOT QAA38452 AT out1 DOT ibm DOT net>; from Mark E. on Wed, Jul 21, 1999 at 12:07:18PM -0400 <199907220030 DOT AAA09334 AT out5 DOT ibm DOT net> Reply-To: djgpp-workers AT delorie DOT com X-Mailing-List: djgpp-workers AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk From: "Mark E." Date: Wed, 21 Jul 1999 20:30:51 -0400 > I fear you're getting yourself into trouble, since there's no > way to change the section alignment in coff. Since the documentation is silent on this, what does COFF_DEFAULT_SECTION_ALIGNMENT_POWER do then? My tests show it does increase the size of the object files and executables accordingly. Richard means that COFF can not change the alignment on a section by section basis (i960 COFF is an exception). The alignment is fixed to a specific value: COFF_DEFAULT_SECTION_ALIGNMENT_POWER. > If you do any sort of collect-sections-to-make-data kinds of > things like .ctors or .dtors, that'll break. Do you know that > you're using collect2 to construct constructor lists? I'm not 100% sure, but I don't think so. The linker script groups them together in the .data section and surrounds them with special symbols (djgpp_first_ctor, etc.) defined in the script. Yes, but *(.ctors) in the linker will align each .ctors section in an input file to COFF_DEFAULT_SECTION_ALIGNMENT_POWER, which will put unsightly zero values in the .ctors section in the output file. Or it would if .ctors and .dtors were not specially handled in coff_new_section_hook in coffcode.h. So you're OK on constructors and destructors if you do indeed use the section names .ctors and .dtors. Ian