PowerPC64 EH info for _notoc linkage stubs

This patch generates EH info for the new _notoc linkage stubs, to
support unwinding from asynchronous signal handlers.  Unwinding
through the __tls_get_addr_opt stub was already supported, but that
was just a single stub.  With multiple stubs the EH opcodes need to be
emitted and sized when iterating over stubs, so this is done when
emitting and sizing the stub code.  Emitting the CIEs and FDEs is done
when sizing the stubs, as we did before in order to have the linker
generated FDEs indexed in .eh_frame_hdr.  I moved the final tweaks to
FDEs from ppc64_elf_finish_dynamic_sections to ppc64_elf_build_stubs
simply because it's tidier to be done with them at that point.

bfd/
	* elf64-ppc.c (struct map_stub): Delete tls_get_addr_opt_bctrl.
	Add lr_restore, eh_size and eh_base.
	(eh_advance, eh_advance_size): New functions.
	(build_tls_get_addr_stub): Emit EH info for stub.
	(ppc_build_one_stub): Likewise for _notoc stubs.
	(ppc_size_one_stub): Size EH info for stub.
	(group_sections): Init new map_stub fields.
	(stub_eh_frame_size): Delete.
	(ppc64_elf_size_stubs): Size EH info for stubs.  Set up dummy EH
	program for stubs.
	(ppc64_elf_build_stubs): Reinit new map_stub fields.  Set FDE
	offset to stub section here..
	(ppc64_elf_finish_dynamic_sections): ..rather than here.
ld/
	* testsuite/ld-powerpc/notoc.s: Generate some cfi.
	* testsuite/ld-powerpc/notoc.d: Adjust.
	* testsuite/ld-powerpc/notoc.wf: New file.
	* testsuite/ld-powerpc/powerpc.exp: Run "ext" and "notoc" tests
	as run_ld_link_tests rather than run_dump_test.

4 files changed, 45 insertions, 9 deletions

diff --git a/ld/testsuite/ld-powerpc/notoc.d b/ld/testsuite/ld-powerpc/notoc.d
index 97e7274..eaafd01 100644
--- a/ld/testsuite/ld-powerpc/notoc.d
+++ b/ld/testsuite/ld-powerpc/notoc.d
@@ -1,7 +1,7 @@
 #source: notoc.s
 #as: -a64
 #ld: --no-plt-localentry -T ext.lnk
-#objdump: -dr
+#objdump: -d
 #target: powerpc64*-*-*
 
 .*
@@ -63,8 +63,8 @@ Disassembly of section \.text:
 .*:	(20 00 80 4e|4e 80 00 20) 	blr
 
 .* <f2>:
-.*:	(02 10 40 3c|3c 40 10 02) 	lis     r2,4098
-.*:	(00 90 42 38|38 42 90 00) 	addi    r2,r2,-28672
+.*:	(01 10 40 3c|3c 40 10 01) 	lis     r2,4097
+.*:	(00 80 42 38|38 42 80 00) 	addi    r2,r2,-32768
 .*:	(4d ff ff 4b|4b ff ff 4d) 	bl      .* <.*\.long_branch\.f1>
 .*:	(18 00 41 e8|e8 41 00 18) 	ld      r2,24\(r1\)
 .*:	(f9 ff ff 4b|4b ff ff f9) 	bl      .* <f2\+0x8>
@@ -78,8 +78,8 @@ Disassembly of section \.text:
 .*:	(20 00 80 4e|4e 80 00 20) 	blr
 
 .* <g2>:
-.*:	(02 10 40 3c|3c 40 10 02) 	lis     r2,4098
-.*:	(00 90 42 38|38 42 90 00) 	addi    r2,r2,-28672
+.*:	(01 10 40 3c|3c 40 10 01) 	lis     r2,4097
+.*:	(00 80 42 38|38 42 80 00) 	addi    r2,r2,-32768
 .*:	(cd ff ff 4b|4b ff ff cd) 	bl      .* <f2\+0x8>
 .*:	(00 00 00 60|60 00 00 00) 	nop
 .*:	(11 ff ff 4b|4b ff ff 11) 	bl      .* <.*\.long_branch\.f1>
@@ -96,7 +96,7 @@ Disassembly of section \.text:
 Disassembly of section \.text\.ext:
 
 8000000000000000 <ext>:
-8000000000000000:	(02 10 40 3c|3c 40 10 02) 	lis     r2,4098
-8000000000000004:	(00 90 42 38|38 42 90 00) 	addi    r2,r2,-28672
+8000000000000000:	(01 10 40 3c|3c 40 10 01) 	lis     r2,4097
+8000000000000004:	(00 80 42 38|38 42 80 00) 	addi    r2,r2,-32768
 8000000000000008:	(00 00 00 60|60 00 00 00) 	nop
 800000000000000c:	(20 00 80 4e|4e 80 00 20) 	blr
diff --git a/ld/testsuite/ld-powerpc/notoc.s b/ld/testsuite/ld-powerpc/notoc.s
index 8c620df..eb881c8 100644
--- a/ld/testsuite/ld-powerpc/notoc.s
+++ b/ld/testsuite/ld-powerpc/notoc.s
@@ -53,4 +53,6 @@ g2:
  blr
 
 _start:
+ .cfi_startproc
  b _start
+ .cfi_endproc
diff --git a/ld/testsuite/ld-powerpc/notoc.wf b/ld/testsuite/ld-powerpc/notoc.wf
new file mode 100644
index 0000000..208d676
--- /dev/null
+++ b/ld/testsuite/ld-powerpc/notoc.wf
@@ -0,0 +1,33 @@
+Contents of the \.eh_frame section:
+
+
+00000000 0000000000000010 00000000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 65
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r1 ofs 0
+
+00000014 0000000000000024 00000018 FDE cie=00000000 pc=00000000100000c0\.\.0000000010000140
+  DW_CFA_advance_loc: 24 to 00000000100000d8
+  DW_CFA_register: r65 in r12
+  DW_CFA_advance_loc: 8 to 00000000100000e0
+  DW_CFA_restore_extended: r65
+  DW_CFA_advance_loc: 40 to 0000000010000108
+  DW_CFA_register: r65 in r12
+  DW_CFA_advance_loc: 8 to 0000000010000110
+  DW_CFA_restore_extended: r65
+  DW_CFA_advance_loc: 16 to 0000000010000120
+  DW_CFA_register: r65 in r12
+  DW_CFA_advance_loc: 8 to 0000000010000128
+  DW_CFA_restore_extended: r65
+  DW_CFA_nop
+  DW_CFA_nop
+
+0000003c 0000000000000010 00000040 FDE cie=00000000 pc=00000000100001cc\.\.00000000100001d0
+  DW_CFA_nop
+  DW_CFA_nop
+  DW_CFA_nop
+
diff --git a/ld/testsuite/ld-powerpc/powerpc.exp b/ld/testsuite/ld-powerpc/powerpc.exp
index c4ab3de..12590f1 100644
--- a/ld/testsuite/ld-powerpc/powerpc.exp
+++ b/ld/testsuite/ld-powerpc/powerpc.exp
@@ -257,6 +257,9 @@ set ppc64elftests {
 	{{objdump -dr tocsave2a.d}} "tocsave2a"}
     {"ambig shared v1" "-shared -melf64ppc" "" "-a64" {funv1.s} {} "funv1.so"}
     {"ambig shared v2" "-shared -melf64ppc" "" "-a64" {funv2.s} {} "funv2.so"}
+    {"notoc ext" "" "" "-a64" {ext.s} {} ""}
+    {"notoc" "-melf64ppc --no-plt-localentry -T ext.lnk" "" "-a64" {notoc.s}
+	{{objdump -d notoc.d} {readelf {-wf -W} notoc.wf}} "notoc"}
 }
 
 set ppceabitests {
@@ -331,8 +334,6 @@ if [ supports_ppc64 ] then {
     run_dump_test "dotsym2"
     run_dump_test "dotsym3"
     run_dump_test "dotsym4"
-    run_dump_test "ext"
-    run_dump_test "notoc"
 }
 
 run_dump_test "tlsld32"