Improve building with LTO

Use symver attribute for symbol versioning instead of .symver
assembler directive when available. Convert to use double @ syntax
for default version in all cases (required when using the attribute).

Add the attributes externally_visible, no_reorder if available when
using assembler directives to improve the situation for < gcc-10.
This is not 100% reliable, though; -flto-partition=none may still be
needed in some cases.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24498
Signed-off-by: Alexander Miller <alex.miller@gmx.de>

10 files changed, 22 insertions, 11 deletions

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 311f34b5..b3836833 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,14 @@
+2021-02-14  Alexander Miller  <alex.miller@gmx.de>
+
+	* dwarf_aggregate_size.c (dwarf_aggregate_size): Move NEW_VERSION
+	before definition.  Replace INTDEF with NEW_INTDEF.
+	* dwarf_srclang.c (dwarf_srclang): Likewise.
+	* dwarf_arrayorder.c (dwarf_arrayorder): Move NEW_VERSION.
+	* dwarf_bitoffset.c (dwarf_bitoffset): Likewise.
+	* dwarf_bitsize.c (dwarf_bitsize): Likewise.
+	* dwarf_bytesize.c (dwarf_bytesize): Likewise.
+	* dwarf_decl_column.c (dwarf_decl_column): Likewise.
+
 2021-10-18  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_aggregate_size.c (get_type): Don't pass NULL to
diff --git a/libdw/dwarf_aggregate_size.c b/libdw/dwarf_aggregate_size.c
index 89f2029e..8216ae42 100644
--- a/libdw/dwarf_aggregate_size.c
+++ b/libdw/dwarf_aggregate_size.c
@@ -241,6 +241,7 @@ aggregate_size (Dwarf_Die *die, Dwarf_Word *size,
   return -1;
 }
 
+NEW_VERSION (dwarf_aggregate_size, ELFUTILS_0.161)
 int
 dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size)
 {
@@ -251,6 +252,5 @@ dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size)
 
   return aggregate_size (&die_mem, size, &type_mem, 0);
 }
-INTDEF (dwarf_aggregate_size)
+NEW_INTDEF (dwarf_aggregate_size)
 OLD_VERSION (dwarf_aggregate_size, ELFUTILS_0.144)
-NEW_VERSION (dwarf_aggregate_size, ELFUTILS_0.161)
diff --git a/libdw/dwarf_arrayorder.c b/libdw/dwarf_arrayorder.c
index da64f992..782e075c 100644
--- a/libdw/dwarf_arrayorder.c
+++ b/libdw/dwarf_arrayorder.c
@@ -35,6 +35,7 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_arrayorder, ELFUTILS_0.143)
 int
 dwarf_arrayorder (Dwarf_Die *die)
 {
@@ -46,4 +47,3 @@ dwarf_arrayorder (Dwarf_Die *die)
 				  &value) == 0 ? (int) value : -1;
 }
 OLD_VERSION (dwarf_arrayorder, ELFUTILS_0.122)
-NEW_VERSION (dwarf_arrayorder, ELFUTILS_0.143)
diff --git a/libdw/dwarf_bitoffset.c b/libdw/dwarf_bitoffset.c
index c1a3a343..61a0d593 100644
--- a/libdw/dwarf_bitoffset.c
+++ b/libdw/dwarf_bitoffset.c
@@ -35,6 +35,7 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_bitoffset, ELFUTILS_0.143)
 int
 dwarf_bitoffset (Dwarf_Die *die)
 {
@@ -46,4 +47,3 @@ dwarf_bitoffset (Dwarf_Die *die)
 				  &value) == 0 ? (int) value : -1;
 }
 OLD_VERSION (dwarf_bitoffset, ELFUTILS_0.122)
-NEW_VERSION (dwarf_bitoffset, ELFUTILS_0.143)
diff --git a/libdw/dwarf_bitsize.c b/libdw/dwarf_bitsize.c
index 0ed9b710..35e8744c 100644
--- a/libdw/dwarf_bitsize.c
+++ b/libdw/dwarf_bitsize.c
@@ -35,6 +35,7 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_bitsize, ELFUTILS_0.143)
 int
 dwarf_bitsize (Dwarf_Die *die)
 {
@@ -46,4 +47,3 @@ dwarf_bitsize (Dwarf_Die *die)
 				  &value) == 0 ? (int) value : -1;
 }
 OLD_VERSION (dwarf_bitsize, ELFUTILS_0.122)
-NEW_VERSION (dwarf_bitsize, ELFUTILS_0.143)
diff --git a/libdw/dwarf_bytesize.c b/libdw/dwarf_bytesize.c
index 116cd321..6d1ff9ae 100644
--- a/libdw/dwarf_bytesize.c
+++ b/libdw/dwarf_bytesize.c
@@ -35,6 +35,7 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_bytesize, ELFUTILS_0.143)
 int
 dwarf_bytesize (Dwarf_Die *die)
 {
@@ -46,4 +47,3 @@ dwarf_bytesize (Dwarf_Die *die)
 				  &value) == 0 ? (int) value : -1;
 }
 OLD_VERSION (dwarf_bytesize, ELFUTILS_0.122)
-NEW_VERSION (dwarf_bytesize, ELFUTILS_0.143)
diff --git a/libdw/dwarf_decl_column.c b/libdw/dwarf_decl_column.c
index 08d36b87..3225fd18 100644
--- a/libdw/dwarf_decl_column.c
+++ b/libdw/dwarf_decl_column.c
@@ -35,10 +35,10 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_decl_column, ELFUTILS_0.143)
 int
 dwarf_decl_column (Dwarf_Die *decl, int *colp)
 {
   return __libdw_attr_intval (decl, colp, DW_AT_decl_column);
 }
 OLD_VERSION (dwarf_decl_column, ELFUTILS_0.122)
-NEW_VERSION (dwarf_decl_column, ELFUTILS_0.143)
diff --git a/libdw/dwarf_decl_file.c b/libdw/dwarf_decl_file.c
index d4aa0a18..75662a33 100644
--- a/libdw/dwarf_decl_file.c
+++ b/libdw/dwarf_decl_file.c
@@ -36,6 +36,7 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_decl_file, ELFUTILS_0.143)
 const char *
 dwarf_decl_file (Dwarf_Die *die)
 {
@@ -86,4 +87,3 @@ dwarf_decl_file (Dwarf_Die *die)
   return cu->files->info[idx].name;
 }
 OLD_VERSION (dwarf_decl_file, ELFUTILS_0.122)
-NEW_VERSION (dwarf_decl_file, ELFUTILS_0.143)
diff --git a/libdw/dwarf_decl_line.c b/libdw/dwarf_decl_line.c
index 80fae6c9..6b31eebe 100644
--- a/libdw/dwarf_decl_line.c
+++ b/libdw/dwarf_decl_line.c
@@ -37,13 +37,13 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_decl_line, ELFUTILS_0.143)
 int
 dwarf_decl_line (Dwarf_Die *func, int *linep)
 {
   return __libdw_attr_intval (func, linep, DW_AT_decl_line);
 }
 OLD_VERSION (dwarf_decl_line, ELFUTILS_0.122)
-NEW_VERSION (dwarf_decl_line, ELFUTILS_0.143)
 
 
 int internal_function
diff --git a/libdw/dwarf_srclang.c b/libdw/dwarf_srclang.c
index f10e7642..77bd58c2 100644
--- a/libdw/dwarf_srclang.c
+++ b/libdw/dwarf_srclang.c
@@ -35,6 +35,7 @@
 #include "libdwP.h"
 
 
+NEW_VERSION (dwarf_srclang, ELFUTILS_0.143)
 int
 dwarf_srclang (Dwarf_Die *die)
 {
@@ -45,6 +46,5 @@ dwarf_srclang (Dwarf_Die *die)
 				  (die, DW_AT_language, &attr_mem),
 				  &value) == 0 ? (int) value : -1;
 }
-INTDEF (dwarf_srclang)
+NEW_INTDEF (dwarf_srclang)
 OLD_VERSION (dwarf_srclang, ELFUTILS_0.122)
-NEW_VERSION (dwarf_srclang, ELFUTILS_0.143)