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.

diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 054f9c72161b75490ed8731a525dc58cbe78a44f..89bc7d3f9b9842149f64ae50e4efd37d2acc7dfc 100644 (file)
--- 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