From 900fa2573671d692ed245f76aa3f05cec462be0c Mon Sep 17 00:00:00 2001
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Wed, 6 Apr 2022 12:09:42 -0300
Subject: stdio: Remove the usage of $(fno-unit-at-a-time) for errlist.c

The errlist.c is built with -fno-toplevel-reorder to avoid compiler to
reorder the compat assembly directives due an assembler issue [1]
(fixed on 2.39).

This patch removes the compiler flags by split the compat symbol
generation in two phases.  First the _sys_errlist_internal internal
without any compat symbol directive is preprocessed to generate an
assembly source code.  This generate assembly is then used as input
on a platform agnostic errlist-data.S which then creates the compat
definitions.  This prevents compiler to move any compat directive
prior the _sys_errlist_internal definition itself.

Checked on a make check run-built-tests=no on all affected ABIs.

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=29012
---
 stdio-common/Makefile | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

(limited to 'stdio-common/Makefile')

diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index a1603e82fe..08bc998436 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -88,6 +88,7 @@ routines := \
 
 aux := \
   errlist \
+  errlist-data \
   errname \
   fxprintf \
   printf-parsemb \
@@ -211,6 +212,10 @@ tests := \
   xbug \
   # tests
 
+generated += \
+  errlist-data-aux-shared.S \
+  errlist-data-aux.S \
+  # generated
 
 test-srcs = tst-unbputc tst-printf tst-printfsz-islongdouble
 
@@ -246,6 +251,20 @@ tests-special += $(objpfx)tst-errno-manual.out
 
 include ../Rules
 
+# The errlist.c is built in two phases because compiler might reorder the
+# compat_symbol directive prior the object itself and on binutils older
+# than 2.29 it might generate object sizes different than the expected ones.
+$(objpfx)errlist-data-aux-shared.S: errlist-data-gen.c
+	$(make-target-directory)
+	$(compile-command.c) $(pic-cppflags) $(pic-ccflag) $(no-stack-protector) -S
+
+$(objpfx)errlist-data-aux.S: errlist-data-gen.c
+	$(make-target-directory)
+	$(compile-command.c) $(pie-default) $(no-stack-protector) -S
+
+$(objpfx)errlist-data.os: $(objpfx)errlist-data-aux-shared.S
+$(objpfx)errlist-data.o: $(objpfx)errlist-data-aux.S
+
 ifeq ($(run-built-tests),yes)
 LOCALES := \
   de_DE.ISO-8859-1 \
@@ -334,7 +353,6 @@ CFLAGS-isoc99_vfscanf.c += -fexceptions
 CFLAGS-isoc99_vscanf.c += -fexceptions
 CFLAGS-isoc99_fscanf.c += -fexceptions
 CFLAGS-isoc99_scanf.c += -fexceptions
-CFLAGS-errlist.c += $(fno-unit-at-a-time)
 CFLAGS-siglist.c += $(fno-unit-at-a-time)
 
 # scanf14a.c and scanf16a.c test a deprecated extension which is no
-- 
cgit v1.2.3