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File gcc7-pfe-0019-Backport-Use-the-section-flag-o-for-__patchable_func.patch of Package gcc7 (Revision 99d2055055cb6d08ca876bc3fccd7e29)

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From 8ef0203090dab33a177f0b45f6bf69246047e463 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 2 Dec 2020 05:32:37 -0800
Subject: [PATCH 19/22] Backport Use the section flag 'o' for
 __patchable_function_entries

This commit in GNU binutils 2.35:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=b7d072167715829eed0622616f6ae0182900de3e

added the section flag 'o' to .section directive:

.section __patchable_function_entries,"awo",@progbits,foo

which specifies the symbol name which the section references.  Assembler
creates a unique __patchable_function_entries section with the section,
where foo is defined, as its linked-to section.  Linker keeps a section
if its linked-to section is kept during garbage collection.

This patch checks assembler support for the section flag 'o' and uses
it to implement __patchable_function_entries section.  Since Solaris may
use GNU assembler with Solairs ld.  Even if GNU assembler supports the
section flag 'o', it doesn't mean that Solairs ld supports it.  This
feature is disabled for Solairs targets.

gcc/

PR middle-end/93195
	PR middle-end/93197
	* configure.ac (HAVE_GAS_SECTION_LINK_ORDER): New.  Define 1 if
	the assembler supports the section flag 'o' for specifying
	section with link-order.
	* output.h (SECTION_LINK_ORDER): New.  Defined to 0x8000000.
	(SECTION_MACH_DEP): Changed from 0x8000000 to 0x10000000.
	* targhooks.c (default_print_patchable_function_entry): Pass
	SECTION_LINK_ORDER to switch_to_section if the section flag 'o'
	works.  Pass current_function_decl to switch_to_section.
	* varasm.c (default_elf_asm_named_section): Use 'o' flag for
	SECTION_LINK_ORDER if assembler supports it.
	* config.in: Regenerated.
	* configure: Likewise.
	* doc/sourcebuild.texi: Document o_flag_in_section.

gcc/testsuite/

PR middle-end/93195
	* g++.dg/pr93195b.C: New test.
	* lib/target-supports.exp
	(check_effective_target_o_flag_in_section): New proc.
---
 gcc/config.in                         |  13 +
 gcc/configure                         | 186 ++++++++++
 gcc/configure.ac                      |  70 ++++
 gcc/doc/sourcebuild.texi              |   9 +
 gcc/output.h                          |   7 +-
 gcc/targhooks.c                       |   5 +-
 gcc/testsuite/g++.dg/pr93195b.C       |  14 +
 gcc/testsuite/lib/target-supports.exp | 493 ++++++++++++++++++++++++++
 gcc/varasm.c                          |  12 +
 9 files changed, 807 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/pr93195b.C

diff --git a/gcc/config.in b/gcc/config.in
index eca3fd810fb..12b61991ff2 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -1315,6 +1315,19 @@
 #endif
 
 
+/* Define 0/1 if your assembler supports 'o' flag in .section directive. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_GAS_SECTION_LINK_ORDER
+#endif
+
+
+/* Define 0/1 if your assembler supports marking sections with SHF_GNU_RETAIN
+   flag. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_GAS_SHF_GNU_RETAIN
+#endif
+
+
 /* Define 0/1 if your assembler supports marking sections with SHF_MERGE flag.
    */
 #ifndef USED_FOR_TARGET
diff --git a/gcc/configure b/gcc/configure
index 5dab9142e1a..06ff33c271b 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -23505,6 +23505,192 @@ $as_echo "#define USE_AS_TRADITIONAL_FORMAT 1" >>confdefs.h
 
 fi
 
+# Test if the assembler supports the section flag 'e' or #exclude for
+# specifying an excluded section.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for section exclude flag" >&5
+$as_echo_n "checking assembler for section exclude flag... " >&6; }
+if ${gcc_cv_as_section_exclude_e+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_section_exclude_e=no
+    if test $in_tree_gas = yes; then
+    if test $gcc_cv_gas_vers -ge `expr $ \( 2 \* 1000 $ + 22 \) \* 1000 + 51`
+  then gcc_cv_as_section_exclude_e=yes
+fi
+  elif test x$gcc_cv_as != x; then
+    $as_echo '.section foo1,"e"
+  .byte 0,0,0,0' > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --fatal-warnings -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_section_exclude_e=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_section_exclude_e" >&5
+$as_echo "$gcc_cv_as_section_exclude_e" >&6; }
+
+
+if test $gcc_cv_as_section_exclude_e = no; then
+  case "${target}" in
+    # Solaris as uses #exclude instead.
+    *-*-solaris2*)
+      case "${target}" in
+	sparc*-*-solaris2*)
+	  conftest_s='.section "foo1", #exclude'
+	  ;;
+	i?86-*-solaris2* | x86_64-*-solaris2*)
+	  conftest_s='.section foo1, #exclude'
+	  ;;
+      esac
+      ;;
+    esac
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for section exclude flag" >&5
+$as_echo_n "checking assembler for section exclude flag... " >&6; }
+if ${gcc_cv_as_section_exclude_hash+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_section_exclude_hash=no
+  if test x$gcc_cv_as != x; then
+    $as_echo "$conftest_s
+     .byte 0,0,0,0" > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags  -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_section_exclude_hash=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_section_exclude_hash" >&5
+$as_echo "$gcc_cv_as_section_exclude_hash" >&6; }
+
+
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_GAS_SECTION_EXCLUDE `if test $gcc_cv_as_section_exclude_e = yes || test $gcc_cv_as_section_exclude_hash = yes; then echo 1; else echo 0; fi`
+_ACEOF
+
+
+# Test if the assembler supports the section flag 'R' for specifying
+# section with SHF_GNU_RETAIN.
+case "${target}" in
+  # Solaris may use GNU assembler with Solairs ld.  Even if GNU
+  # assembler supports the section flag 'R', it doesn't mean that
+  # Solairs ld supports it.
+  *-*-solaris2*)
+    gcc_cv_as_shf_gnu_retain=no
+    ;;
+  *)
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for section 'R' flag" >&5
+$as_echo_n "checking assembler for section 'R' flag... " >&6; }
+if ${gcc_cv_as_shf_gnu_retain+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_shf_gnu_retain=no
+    if test $in_tree_gas = yes; then
+    if test $in_tree_gas_is_elf = yes \
+  && test $gcc_cv_gas_vers -ge `expr $ \( 2 \* 1000 $ + 36 \) \* 1000 + 0`
+  then gcc_cv_as_shf_gnu_retain=yes
+fi
+  elif test x$gcc_cv_as != x; then
+    $as_echo '.section .foo,"awR",%progbits
+.byte 0' > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --fatal-warnings -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_shf_gnu_retain=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_shf_gnu_retain" >&5
+$as_echo "$gcc_cv_as_shf_gnu_retain" >&6; }
+
+
+    ;;
+esac
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_GAS_SHF_GNU_RETAIN `if test $gcc_cv_as_shf_gnu_retain = yes; then echo 1; else echo 0; fi`
+_ACEOF
+
+
+# Test if the assembler supports the section flag 'o' for specifying
+# section with link-order.
+case "${target}" in
+  # Solaris may use GNU assembler with Solairs ld.  Even if GNU
+  # assembler supports the section flag 'o', it doesn't mean that
+  # Solairs ld supports it.
+  *-*-solaris2*)
+    gcc_cv_as_section_link_order=no
+    ;;
+  *)
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for section 'o' flag" >&5
+$as_echo_n "checking assembler for section 'o' flag... " >&6; }
+if ${gcc_cv_as_section_link_order+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_section_link_order=no
+    if test $in_tree_gas = yes; then
+    if test $gcc_cv_gas_vers -ge `expr $ \( 2 \* 1000 $ + 35 \) \* 1000 + 0`
+  then gcc_cv_as_section_link_order=yes
+fi
+  elif test x$gcc_cv_as != x; then
+    $as_echo '.section .foo,"a"
+.byte 0
+.section __patchable_function_entries,"awo",%progbits,.foo
+.byte 0' > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --fatal-warnings -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_section_link_order=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_section_link_order" >&5
+$as_echo "$gcc_cv_as_section_link_order" >&6; }
+
+
+    ;;
+esac
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_GAS_SECTION_LINK_ORDER `if test $gcc_cv_as_section_link_order = yes; then echo 1; else echo 0; fi`
+_ACEOF
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for section merging support" >&5
 $as_echo_n "checking assembler for section merging support... " >&6; }
 if test "${gcc_cv_as_shf_merge+set}" = set; then :
diff --git a/gcc/configure.ac b/gcc/configure.ac
index e1fa8af5e4f..8bef9fd27b4 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -2938,6 +2938,76 @@ if test $gcc_cv_as_eh_frame = buggy; then
   [Define if your assembler mis-optimizes .eh_frame data.])
 fi
 
+# Test if the assembler supports the section flag 'e' or #exclude for
+# specifying an excluded section.
+gcc_GAS_CHECK_FEATURE([section exclude flag], gcc_cv_as_section_exclude_e,
+ [2,22,51], [--fatal-warnings],
+ [.section foo1,"e"
+  .byte 0,0,0,0])
+if test $gcc_cv_as_section_exclude_e = no; then
+  case "${target}" in
+    # Solaris as uses #exclude instead.
+    *-*-solaris2*)
+      case "${target}" in
+	sparc*-*-solaris2*)
+	  conftest_s='.section "foo1", #exclude'
+	  ;;
+	i?86-*-solaris2* | x86_64-*-solaris2*)
+	  conftest_s='.section foo1, #exclude'
+	  ;;      
+      esac
+      ;;
+    esac
+  gcc_GAS_CHECK_FEATURE([section exclude flag], gcc_cv_as_section_exclude_hash,,,
+    [$conftest_s
+     .byte 0,0,0,0])
+fi
+AC_DEFINE_UNQUOTED(HAVE_GAS_SECTION_EXCLUDE,
+  [`if test $gcc_cv_as_section_exclude_e = yes || test $gcc_cv_as_section_exclude_hash = yes; then echo 1; else echo 0; fi`],
+[Define if your assembler supports specifying the exclude section flag.])
+
+# Test if the assembler supports the section flag 'R' for specifying
+# section with SHF_GNU_RETAIN.
+case "${target}" in
+  # Solaris may use GNU assembler with Solairs ld.  Even if GNU
+  # assembler supports the section flag 'R', it doesn't mean that
+  # Solairs ld supports it.
+  *-*-solaris2*)
+    gcc_cv_as_shf_gnu_retain=no
+    ;;
+  *)
+    gcc_GAS_CHECK_FEATURE([section 'R' flag], gcc_cv_as_shf_gnu_retain,
+      [elf,2,36,0], [--fatal-warnings],
+      [.section .foo,"awR",%progbits
+.byte 0])
+    ;;
+esac
+AC_DEFINE_UNQUOTED(HAVE_GAS_SHF_GNU_RETAIN,
+  [`if test $gcc_cv_as_shf_gnu_retain = yes; then echo 1; else echo 0; fi`],
+  [Define 0/1 if your assembler supports marking sections with SHF_GNU_RETAIN flag.])
+
+# Test if the assembler supports the section flag 'o' for specifying
+# section with link-order.
+case "${target}" in
+  # Solaris may use GNU assembler with Solairs ld.  Even if GNU
+  # assembler supports the section flag 'o', it doesn't mean that
+  # Solairs ld supports it.
+  *-*-solaris2*)
+    gcc_cv_as_section_link_order=no
+    ;;
+  *)
+    gcc_GAS_CHECK_FEATURE([section 'o' flag], gcc_cv_as_section_link_order,
+      [2,35,0], [--fatal-warnings],
+      [.section .foo,"a"
+.byte 0
+.section __patchable_function_entries,"awo",%progbits,.foo
+.byte 0])
+    ;;
+esac
+AC_DEFINE_UNQUOTED(HAVE_GAS_SECTION_LINK_ORDER,
+  [`if test $gcc_cv_as_section_link_order = yes; then echo 1; else echo 0; fi`],
+  [Define 0/1 if your assembler supports 'o' flag in .section directive.])
+
 gcc_GAS_CHECK_FEATURE(section merging support, gcc_cv_as_shf_merge,
  [elf,2,12,0], [--fatal-warnings],
  [.section .rodata.str, "aMS", @progbits, 1])
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index f0e9bb8d35f..6d81c4a937d 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2072,6 +2072,15 @@ Target uses natural alignment (aligned to type size) for types of
 @item nonpic
 Target does not generate PIC by default.
 
+@item o_flag_in_section
+Target supports the 'o' flag in .section directive in assembly inputs.
+
+@item offload_gcn
+Target has been configured for OpenACC/OpenMP offloading on AMD GCN.
+
+@item persistent
+Target supports the @code{persistent} variable attribute.
+
 @item pie_enabled
 Target generates PIE by default.
 
diff --git a/gcc/output.h b/gcc/output.h
index 7a93fa89cab..049f184e009 100644
--- a/gcc/output.h
+++ b/gcc/output.h
@@ -383,7 +383,12 @@ extern void no_asm_to_stream (FILE *);
 #define SECTION_COMMON   0x800000	/* contains common data */
 #define SECTION_RELRO	 0x1000000	/* data is readonly after relocation processing */
 #define SECTION_EXCLUDE  0x2000000	/* discarded by the linker */
-#define SECTION_MACH_DEP 0x4000000	/* subsequent bits reserved for target */
+#define SECTION_RETAIN	 0x4000000	/* retained by the linker.  */
+#define SECTION_LINK_ORDER 0x8000000	/* section needs link-order.  */
+
+/* NB: The maximum SECTION_MACH_DEP is 0x10000000 since AVR needs 4 bits
+   in SECTION_MACH_DEP.  */
+#define SECTION_MACH_DEP 0x10000000	/* subsequent bits reserved for target */
 
 /* This SECTION_STYLE is used for unnamed sections that we can switch
    to using a special assembler directive.  */
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index 185dc7b0b6b..8aa610f5cde 100644
--- a/gcc/targhooks.c
+++ b/gcc/targhooks.c
@@ -1642,8 +1642,11 @@ default_print_patchable_function_entry (FILE *file,
       patch_area_number++;
       ASM_GENERATE_INTERNAL_LABEL (buf, "LPFE", patch_area_number);
 
+      unsigned int flags = SECTION_WRITE | SECTION_RELRO;
+      if (HAVE_GAS_SECTION_LINK_ORDER)
+	flags |= SECTION_LINK_ORDER;
       switch_to_section (get_section ("__patchable_function_entries",
-				      SECTION_WRITE | SECTION_RELRO, NULL));
+				      flags, current_function_decl));
       assemble_align (POINTER_SIZE);
       fputs (asm_op, file);
       assemble_name_raw (file, buf);
diff --git a/gcc/testsuite/g++.dg/pr93195b.C b/gcc/testsuite/g++.dg/pr93195b.C
new file mode 100644
index 00000000000..303d8588c0f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr93195b.C
@@ -0,0 +1,14 @@
+/* { dg-do compile { target { ! { nvptx*-*-* visium-*-* } } } } */
+/* { dg-options "-O0 -fpatchable-function-entry=1" } */
+/* { dg-additional-options "-fno-pie" { target sparc*-*-* } } */
+
+inline void
+foo (void)
+{
+}
+
+void
+bar1 (void)
+{
+  foo ();
+}
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index d33136f7aa4..37d5d5432f8 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -8445,3 +8445,496 @@ proc check_effective_target_arm_coproc4_ok { } {
     return [check_cached_effective_target arm_coproc4_ok \
 		check_effective_target_arm_coproc4_ok_nocache]
 }
+
+# Return 1 if the target supports the auto_inc_dec optimization pass.
+proc check_effective_target_autoincdec { } {
+    if { ![check_no_compiler_messages auto_incdec assembly { void f () { }
+	 } "-O2 -fdump-rtl-auto_inc_dec" ] } {
+      return 0
+    }
+
+    set dumpfile [glob -nocomplain "auto_incdec[pid].c.\[0-9\]\[0-9\]\[0-9\]r.auto_inc_dec"]
+    if { [file exists $dumpfile ] } {
+	file delete $dumpfile
+	return 1
+    }
+    return 0
+}
+
+# Return 1 if the target has support for stack probing designed
+# to avoid stack-clash style attacks.
+#
+# This is used to restrict the stack-clash mitigation tests to
+# just those targets that have been explicitly supported.
+# 
+# In addition to the prologue work on those targets, each target's
+# properties should be described in the functions below so that
+# tests do not become a mess of unreadable target conditions.
+# 
+proc check_effective_target_supports_stack_clash_protection { } {
+
+    if { [istarget x86_64-*-*] || [istarget i?86-*-*] 
+	  || [istarget powerpc*-*-*] || [istarget rs6000*-*-*]
+	  || [istarget aarch64*-**] || [istarget s390*-*-*] } {
+	return 1
+    }
+  return 0
+}
+
+# Return 1 if the target creates a frame pointer for non-leaf functions
+# Note we ignore cases where we apply tail call optimization here.
+proc check_effective_target_frame_pointer_for_non_leaf { } {
+  # Solaris/x86 defaults to -fno-omit-frame-pointer.
+  if { [istarget i?86-*-solaris*] || [istarget x86_64-*-solaris*] } {
+    return 1
+  }
+
+  return 0
+}
+
+# Return 1 if the target's calling sequence or its ABI
+# create implicit stack probes at or prior to function entry.
+proc check_effective_target_caller_implicit_probes { } {
+
+  # On x86/x86_64 the call instruction itself pushes the return
+  # address onto the stack.  That is an implicit probe of *sp.
+  if { [istarget x86_64-*-*] || [istarget i?86-*-*] } {
+	return 1
+  }
+
+  # On PPC, the ABI mandates that the address of the outer
+  # frame be stored at *sp.  Thus each allocation of stack
+  # space is itself an implicit probe of *sp.
+  if { [istarget powerpc*-*-*] || [istarget rs6000*-*-*] } {
+	return 1
+  }
+
+  # s390's ABI has a register save area allocated by the
+  # caller for use by the callee.  The mere existence does
+  # not constitute a probe by the caller, but when the slots
+  # used by the callee those stores are implicit probes.
+  if { [istarget s390*-*-*] } {
+	return 1
+  }
+
+  # Not strictly true on aarch64, but we have agreed that we will
+  # consider any function that pushes SP more than 3kbytes into
+  # the guard page as broken.  This essentially means that we can
+  # consider the aarch64 as having a caller implicit probe at
+  # *(sp + 1k).
+  if { [istarget aarch64*-*-*] } {
+	return 1;
+  }
+
+  return 0
+}
+
+# Targets that potentially realign the stack pointer often cause residual
+# stack allocations and make it difficult to elimination loops or residual
+# allocations for dynamic stack allocations
+proc check_effective_target_callee_realigns_stack { } {
+  if { [istarget x86_64-*-*] || [istarget i?86-*-*] } {
+	return 1
+  }
+  return 0
+}
+
+# Return 1 if CET instructions can be compiled.
+proc check_effective_target_cet { } {
+    if { !([istarget i?86-*-*] || [istarget x86_64-*-*]) } {
+	return 0
+    }
+    return [check_no_compiler_messages cet object {
+	void foo (void)
+	{
+	  asm ("setssbsy");
+	}
+    } "-O2 -fcf-protection" ]
+}
+
+# Return 1 if target supports floating point "infinite"
+proc check_effective_target_inf { } {
+    return [check_no_compiler_messages supports_inf assembly {
+        const double pinf = __builtin_inf ();
+    }]
+}
+
+# Return 1 if target supports floating point "infinite" for float.
+proc check_effective_target_inff { } {
+    return [check_no_compiler_messages supports_inff assembly {
+        const float pinf = __builtin_inff ();
+    }]
+}
+
+# Return 1 if the target supports ARMv8.3 Adv.SIMD Complex instructions
+# instructions, 0 otherwise.  The test is valid for ARM and for AArch64.
+# Record the command line options needed.
+
+proc check_effective_target_arm_v8_3a_complex_neon_ok_nocache { } {
+    global et_arm_v8_3a_complex_neon_flags
+    set et_arm_v8_3a_complex_neon_flags ""
+
+    if { ![istarget arm*-*-*] && ![istarget aarch64*-*-*] } {
+        return 0;
+    }
+
+    # Iterate through sets of options to find the compiler flags that
+    # need to be added to the -march option.
+    foreach flags {"" "-mfloat-abi=softfp -mfpu=auto" "-mfloat-abi=hard -mfpu=auto"} {
+        if { [check_no_compiler_messages_nocache \
+                  arm_v8_3a_complex_neon_ok object {
+            #if !defined (__ARM_FEATURE_COMPLEX)
+            #error "__ARM_FEATURE_COMPLEX not defined"
+            #endif
+        } "$flags -march=armv8.3-a"] } {
+            set et_arm_v8_3a_complex_neon_flags "$flags -march=armv8.3-a"
+            return 1
+        }
+    }
+
+    return 0;
+}
+
+proc check_effective_target_arm_v8_3a_complex_neon_ok { } {
+    return [check_cached_effective_target arm_v8_3a_complex_neon_ok \
+                check_effective_target_arm_v8_3a_complex_neon_ok_nocache]
+}
+
+proc add_options_for_arm_v8_3a_complex_neon { flags } {
+    if { ! [check_effective_target_arm_v8_3a_complex_neon_ok] } {
+        return "$flags"
+    }
+    global et_arm_v8_3a_complex_neon_flags
+    return "$flags $et_arm_v8_3a_complex_neon_flags"
+}
+
+# Return 1 if the target supports executing AdvSIMD instructions from ARMv8.3
+# with the complex instruction extension, 0 otherwise.  The test is valid for
+# ARM and for AArch64.
+
+proc check_effective_target_arm_v8_3a_complex_neon_hw { } {
+    if { ![check_effective_target_arm_v8_3a_complex_neon_ok] } {
+        return 0;
+    }
+    return [check_runtime arm_v8_3a_complex_neon_hw_available {
+        #include "arm_neon.h"
+        int
+        main (void)
+        {
+
+          float32x2_t results = {-4.0,5.0};
+          float32x2_t a = {1.0,3.0};
+          float32x2_t b = {2.0,5.0};
+
+          #ifdef __ARM_ARCH_ISA_A64
+          asm ("fcadd %0.2s, %1.2s, %2.2s, #90"
+               : "=w"(results)
+               : "w"(a), "w"(b)
+               : /* No clobbers.  */);
+
+          #else
+          asm ("vcadd.f32 %P0, %P1, %P2, #90"
+               : "=w"(results)
+               : "w"(a), "w"(b)
+               : /* No clobbers.  */);
+          #endif
+
+          return (results[0] == 8 && results[1] == 24) ? 1 : 0;
+        }
+    } [add_options_for_arm_v8_3a_complex_neon ""]]
+}
+
+# Return 1 if the assembler supports assembling the Armv8.3 pointer authentication B key directive
+proc check_effective_target_arm_v8_3a_bkey_directive { } {
+	return [check_no_compiler_messages cet object {
+		int main(void) {
+			asm (".cfi_b_key_frame");
+			return 0;
+		}
+	}]
+}
+
+# Return 1 if the target supports executing the Armv8.1-M Mainline Low
+# Overhead Loop, 0 otherwise.  The test is valid for ARM.
+
+proc check_effective_target_arm_v8_1_lob_ok { } {
+    if { ![check_effective_target_arm_cortex_m] } {
+        return 0;
+    } else {
+	return [check_runtime arm_v8_1_lob_hw_available {
+		int
+		main (void)
+	        { int i = 0;
+		  asm  ("movw r3, #10\n\t" /* movs? */
+			"dls lr, r3" : : : "r3", "lr");
+		 loop:
+		  i++;
+		  asm goto ("le lr, %l0" : : : "lr" : loop);
+		  return i != 10;
+		}
+	} "-march=armv8.1-m.main -mthumb" ]
+    }
+}
+
+# Return 1 is this is an ARM target where -mthumb causes Thumb-2 to be
+# used and the target does not support executing the Armv8.1-M
+# Mainline Low Overhead Loop, 0 otherwise.  The test is valid for ARM.
+
+proc check_effective_target_arm_thumb2_ok_no_arm_v8_1_lob { } {
+    if { [check_effective_target_arm_thumb2_ok]
+	 && ![check_effective_target_arm_v8_1_lob_ok] } {
+	return 1
+    }
+    return 0
+}
+
+# Returns 1 if the target is using glibc, 0 otherwise.
+
+proc check_effective_target_glibc { } {
+    return [check_no_compiler_messages glibc_object assembly {
+  #include <stdlib.h>
+	#if !defined(__GLIBC__)
+	#error undefined
+	#endif
+    }]
+}
+
+# Return 1 if the target plus current options supports a vector
+# complex addition with rotate of half and single float modes, 0 otherwise.
+#
+# This won't change for different subtargets so cache the result.
+
+foreach N {hf sf} {
+    eval [string map [list N $N] {
+        proc check_effective_target_vect_complex_rot_N { } {
+            return [check_cached_effective_target_indexed vect_complex_rot_N {
+            expr { [istarget aarch64*-*-*]
+                    || [istarget arm*-*-*] }}]
+        }
+    }]
+}
+
+# Return 1 if the target plus current options supports a vector
+# complex addition with rotate of double float modes, 0 otherwise.
+#
+# This won't change for different subtargets so cache the result.
+
+foreach N {df} {
+    eval [string map [list N $N] {
+        proc check_effective_target_vect_complex_rot_N { } {
+            return [check_cached_effective_target_indexed vect_complex_rot_N {
+            expr { [istarget aarch64*-*-*] }}]
+        }
+    }]
+}
+
+# Return 1 if this target uses an LLVM assembler and/or linker
+proc check_effective_target_llvm_binutils { } {
+    return [check_cached_effective_target llvm_binutils {
+	      expr { [istarget amdgcn*-*-*]
+		     || [check_effective_target_offload_gcn] }}]
+}
+
+# Return 1 if the compiler supports '-mfentry'.
+
+proc check_effective_target_mfentry { } {
+    if { !([istarget i?86-*-*] || [istarget x86_64-*-*]) } {
+        return 0
+    }
+    return [check_no_compiler_messages mfentry object {
+	        void foo (void) { }
+    } "-mfentry"]
+}
+
+# Return 1 if this target supports indirect calls
+proc check_effective_target_indirect_calls { } {
+  if { [istarget bpf-*-*] } {
+        return 0
+  }
+  return 1
+}
+
+# Return 1 if we can use the -lgccjit option, 0 otherwise.
+
+proc check_effective_target_lgccjit { } {
+  if { [info procs jit_target_compile] == "" } then {
+    global GCC_UNDER_TEST
+    if ![info exists GCC_UNDER_TEST] {
+      set GCC_UNDER_TEST "[find_gcc]"
+    }
+    proc jit_target_compile { source dest type options } [info body gcc_target_compile]
+  }
+  return [check_no_compiler_messages lgccjit executable {
+     int main() { return 0; }
+  } "-lgccjit"]
+}
+
+# Return 1 if the MSP430 small memory model is in use.
+proc check_effective_target_msp430_small {} {
+    return [check_no_compiler_messages msp430_small assembly {
+	#if (!defined __MSP430__ || defined __MSP430X_LARGE__)
+	#error !msp430 || __MSP430X_LARGE__
+	#endif
+    } ""]
+}
+
+# Return 1 if the MSP430 large memory model is in use.
+proc check_effective_target_msp430_large {} {
+    return [check_no_compiler_messages msp430_large assembly {
+	#ifndef __MSP430X_LARGE__
+	#error __MSP430X_LARGE__
+	#endif
+    } ""]
+}
+
+# Return 1 if the target has an efficient means to encode large initializers
+# in the assembly.
+
+proc check_effective_target_large_initializer { } {
+    if { [istarget nvptx*-*-*] } {
+	return 0
+    }
+
+    return 1
+}
+
+# Return 1 if the target allows function prototype mismatches
+# in the assembly.
+
+proc check_effective_target_non_strict_prototype { } {
+    if { [istarget nvptx*-*-*] } {
+	return 0
+    }
+
+    return 1
+}
+
+# Returns 1 if the target toolchain supports extended
+# syntax of .symver directive, 0 otherwise.
+
+proc check_symver_available { } {
+    return [check_no_compiler_messages symver_available object {
+	    int foo(void) { return 0; }
+	    int main (void) {
+		asm volatile (".symver foo,foo@VER_1, local");
+		return 0;
+	    }
+	}]
+}
+
+# Return 1 if emitted assembly contains .ident directive.
+
+proc check_effective_target_ident_directive {} {
+    return [check_no_messages_and_pattern ident_directive \
+		"(?n)^\[\t\]+\\.ident" assembly {
+	int i;
+    }]
+}
+
+# Return 1 if we're able to assemble movdiri and movdir64b
+
+proc check_effective_target_movdir { } {
+    return [check_no_compiler_messages movdir object {
+	void
+	foo (unsigned int *d, unsigned int s)
+	{
+	  __builtin_ia32_directstoreu_u32 (d, s);
+	}
+	void
+	bar (void *d, const void *s)
+	{
+	  __builtin_ia32_movdir64b (d, s);
+	}
+    } "-mmovdiri -mmovdir64b" ]
+}
+
+# Return 1 if target is not support address sanitize, 1 otherwise.
+
+proc check_effective_target_no_fsanitize_address {} {
+    if ![check_no_compiler_messages fsanitize_address executable {
+	int main (void) { return 0; }
+    }] {
+	return 1;
+    }
+    return 0;
+}
+
+# Return 1 if this target supports 'R' flag in .section directive, 0
+# otherwise.  Cache the result.
+
+proc check_effective_target_R_flag_in_section { } {
+    global tool
+    global GCC_UNDER_TEST
+
+    # Need auto-host.h to check linker support.
+    if { ![file exists ../../auto-host.h ] } {
+	return 0
+    }
+
+    return [check_cached_effective_target R_flag_in_section {
+
+	set src pie[pid].c
+	set obj pie[pid].o
+
+	set f [open $src "w"]
+	puts $f "#include \"../../auto-host.h\""
+	puts $f "#if HAVE_GAS_SHF_GNU_RETAIN == 0"
+	puts $f "# error Assembler does not support 'R' flag in .section directive."
+	puts $f "#endif"
+	close $f
+
+	verbose "check_effective_target_R_flag_in_section compiling testfile $src" 2
+	set lines [${tool}_target_compile $src $obj assembly ""]
+
+	file delete $src
+	file delete $obj
+
+	if [string match "" $lines] then {
+	    verbose "check_effective_target_R_flag_in_section testfile compilation passed" 2
+	    return 1
+	} else {
+	    verbose "check_effective_target_R_flag_in_section testfile compilation failed" 2
+	    return 0
+	}
+    }]
+}
+
+# Return 1 if this target supports 'o' flag in .section directive, 0
+# otherwise.  Cache the result.
+
+proc check_effective_target_o_flag_in_section { } {
+    global tool
+    global GCC_UNDER_TEST
+
+    # Need auto-host.h to check linker support.
+    if { ![file exists ../../auto-host.h ] } {
+	return 0
+    }
+
+    return [check_cached_effective_target o_flag_in_section {
+
+	set src pie[pid].c
+	set obj pie[pid].o
+
+	set f [open $src "w"]
+	puts $f "#include \"../../auto-host.h\""
+	puts $f "#if HAVE_GAS_SECTION_LINK_ORDER == 0"
+	puts $f "# error Assembler does not support 'o' flag in .section directive."
+	puts $f "#endif"
+	close $f
+
+	verbose "check_effective_target_o_flag_in_section compiling testfile $src" 2
+	set lines [${tool}_target_compile $src $obj object ""]
+
+	file delete $src
+	file delete $obj
+
+	if [string match "" $lines] then {
+	    verbose "check_effective_target_o_flag_in_section testfile compilation passed" 2
+	    return 1
+	} else {
+	    verbose "check_effective_target_o_flag_in_section testfile compilation failed" 2
+	    return 0
+	}
+    }]
+}
diff --git a/gcc/varasm.c b/gcc/varasm.c
index 8d4c0386fe3..7b0792ddaed 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -6398,6 +6398,10 @@ default_elf_asm_named_section (const char *name, unsigned int flags,
 	*f++ = TLS_SECTION_ASM_FLAG;
       if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
 	*f++ = 'G';
+      if (flags & SECTION_RETAIN)
+	*f++ = 'R';
+      if (flags & SECTION_LINK_ORDER)
+	*f++ = 'o';
 #ifdef MACH_DEP_SECTION_ASM_FLAG
       if (flags & SECTION_MACH_DEP)
 	*f++ = MACH_DEP_SECTION_ASM_FLAG;
@@ -6426,6 +6430,14 @@ default_elf_asm_named_section (const char *name, unsigned int flags,
 
       if (flags & SECTION_ENTSIZE)
 	fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
+      if (flags & SECTION_LINK_ORDER)
+	{
+	  tree id = DECL_ASSEMBLER_NAME (decl);
+	  ultimate_transparent_alias_target (&id);
+	  const char *name = IDENTIFIER_POINTER (id);
+	  name = targetm.strip_name_encoding (name);
+	  fprintf (asm_out_file, ",%s", name);
+	}
       if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
 	{
 	  if (TREE_CODE (decl) == IDENTIFIER_NODE)
-- 
2.33.1

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File gcc7-pfe-0019-Backport-Use-the-section-flag-o-for-__patchable_func.patch of Package gcc7 (Revision 99d2055055cb6d08ca876bc3fccd7e29)

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