PR ld/21334: Always call `_bfd_elf_link_renumber_dynsyms' if required

Complement commit e17b0c351f0b ("MIPS/BFD: Respect the ELF gABI dynamic
symbol table sort requirement") and correct an inconsistency in dynamic
symbol accounting data causing an assertion failure in the MIPS backend:

ld: BFD (GNU Binutils) 2.28.51.20170330 assertion fail
../../binutils-gdb/bfd/elfxx-mips.c:3860

in the course of making a GOT entry in a static binary to satisfy a GOT
relocation present in input, due to the local dynamic symbol count not
having been established.

To do so let backends request `_bfd_elf_link_renumber_dynsyms' to be
always called, rather than where a dynamic binary is linked only, and
then make this request in the MIPS backend.

	bfd/
	PR ld/21334
	* elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
	member.
	* elfxx-target.h [!elf_backend_always_renumber_dynsyms]
	(elf_backend_always_renumber_dynsyms): Define.
	(elfNN_bed): Initialize `always_renumber_dynsyms' member.
	* elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
	* elflink.c (bfd_elf_size_dynamic_sections): Also call
	`_bfd_elf_link_renumber_dynsyms' if the backend has requested
	it.
	(bfd_elf_size_dynsym_hash_dynstr): Likewise.

	ld/
	PR ld/21334
	* testsuite/ld-mips-elf/pr21334.dd: New test.
	* testsuite/ld-mips-elf/pr21334.gd: New test.
	* testsuite/ld-mips-elf/pr21334.ld: New test linker script.
	* testsuite/ld-mips-elf/pr21334.s: New test source.
	* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.

5 files changed, 60 insertions, 0 deletions

diff --git a/ld/testsuite/ld-mips-elf/mips-elf.exp b/ld/testsuite/ld-mips-elf/mips-elf.exp
index 3ef9963..f824e7c 100644
--- a/ld/testsuite/ld-mips-elf/mips-elf.exp
+++ b/ld/testsuite/ld-mips-elf/mips-elf.exp
@@ -1129,3 +1129,13 @@ if { $linux_gnu } {
 		  "export-$class-ref"]]
     }
 }
+
+# PR ld/21334 GOT relocation in static binary test.
+run_ld_link_tests [list \
+    [list \
+	"PR ld/21233 MIPS GOT16 relocation in static binary" \
+	"$abi_ldflags(o32) -e foo -T pr21334.ld" "" "$abi_asflags(o32)" \
+	{pr21334.s} \
+	{{objdump {-d --prefix-addresses} pr21334.dd} \
+	 {readelf -A pr21334.gd}} \
+	"pr21334"]]
diff --git a/ld/testsuite/ld-mips-elf/pr21334.dd b/ld/testsuite/ld-mips-elf/pr21334.dd
new file mode 100644
index 0000000..01c3718
--- /dev/null
+++ b/ld/testsuite/ld-mips-elf/pr21334.dd
@@ -0,0 +1,10 @@
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+[0-9a-f]+ <[^>]*> lui	gp,0x1
+[0-9a-f]+ <[^>]*> addiu	gp,gp,-32736
+[0-9a-f]+ <[^>]*> addu	gp,gp,t9
+[0-9a-f]+ <[^>]*> lw	v0,-32744\(gp\)
+[0-9a-f]+ <[^>]*> jr	ra
+[0-9a-f]+ <[^>]*> addiu	v0,v0,4
+	\.\.\.
diff --git a/ld/testsuite/ld-mips-elf/pr21334.gd b/ld/testsuite/ld-mips-elf/pr21334.gd
new file mode 100644
index 0000000..c8467ee
--- /dev/null
+++ b/ld/testsuite/ld-mips-elf/pr21334.gd
@@ -0,0 +1,11 @@
+Static GOT:
+ Canonical gp value: 00008020
+
+ Reserved entries:
+   Address     Access    Value
+  00000030 -32752\(gp\) 00000000
+  00000034 -32748\(gp\) 80000000
+
+ Local entries:
+   Address     Access    Value
+  00000038 -32744\(gp\) 00000000
diff --git a/ld/testsuite/ld-mips-elf/pr21334.ld b/ld/testsuite/ld-mips-elf/pr21334.ld
new file mode 100644
index 0000000..5fb94bd
--- /dev/null
+++ b/ld/testsuite/ld-mips-elf/pr21334.ld
@@ -0,0 +1,9 @@
+SECTIONS
+{
+  .text : { *(.text) }
+  HIDDEN (_gp = ALIGN (16) + 0x7ff0);
+  .got : { *(.got) }
+  .symtab : { *(.symtab) }
+  .strtab : { *(.strtab) }
+  /DISCARD/ : { *(*) }
+}
diff --git a/ld/testsuite/ld-mips-elf/pr21334.s b/ld/testsuite/ld-mips-elf/pr21334.s
new file mode 100644
index 0000000..d62c18c
--- /dev/null
+++ b/ld/testsuite/ld-mips-elf/pr21334.s
@@ -0,0 +1,20 @@
+	.abicalls
+	.text
+	.set	noreorder
+	.globl	foo
+	.ent	foo
+foo:
+	.frame	$sp, 0, $31
+	.mask	0x00000000, 0
+	.fmask	0x00000000, 0
+	.cpload	$25
+	lw	$2, %got(bar)($28)
+	jr	$31
+	 addiu	$2, $2, 4
+	.end	foo
+	.weak	bar
+	.hidden	bar
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16