From cebc89b9328eab994f6b0314c263f94e7949a553 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Mon, 21 Feb 2022 10:58:57 +1030 Subject: [PATCH] binutils 2.38 vs. ppc32 linux kernel Commit b25f942e18d6 made .machine more strict. Weaken it again. * config/tc-ppc.c (ppc_machine): Treat an early .machine specially, keeping sticky options to work around gcc bugs. --- gas/config/tc-ppc.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c index 054f9c72161..89bc7d3f9b9 100644 --- a/gas/config/tc-ppc.c +++ b/gas/config/tc-ppc.c @@ -5965,7 +5965,30 @@ ppc_machine (int ignore ATTRIBUTE_UNUSED) options do not count as a new machine, instead they add to currently selected opcodes. */ ppc_cpu_t machine_sticky = 0; - new_cpu = ppc_parse_cpu (ppc_cpu, &machine_sticky, cpu_string); + /* Unfortunately, some versions of gcc emit a .machine + directive very near the start of the compiler's assembly + output file. This is bad because it overrides user -Wa + cpu selection. Worse, there are versions of gcc that + emit the *wrong* cpu, not even respecting the -mcpu given + to gcc. See gcc pr101393. And to compound the problem, + as of 20220222 gcc doesn't pass the correct cpu option to + gas on the command line. See gcc pr59828. Hack around + this by keeping sticky options for an early .machine. */ + asection *sec; + for (sec = stdoutput->sections; sec != NULL; sec = sec->next) + { + segment_info_type *info = seg_info (sec); + /* Are the frags for this section perturbed from their + initial state? Even .align will count here. */ + if (info != NULL + && (info->frchainP->frch_root != info->frchainP->frch_last + || info->frchainP->frch_root->fr_type != rs_fill + || info->frchainP->frch_root->fr_fix != 0)) + break; + } + new_cpu = ppc_parse_cpu (ppc_cpu, + sec == NULL ? &sticky : &machine_sticky, + cpu_string); if (new_cpu != 0) ppc_cpu = new_cpu; else -- 2.35.1