ARM: Fix exidx coverage for relocatable builds.

bfd  * elf-bfd.h: Add callback to count additional relocations.
     * elf32-arm.c (_arm_elf_section_data): Add new counter.
     (insert_cantunwind_after): Increment relocations counter.
     (elf32_arm_fix_exidx_coverage): Remove exidx entries and add
     terminating CANTUNWIND entry only in final builds.
     (elf32_arm_add_relocation): New function.
     (elf32_arm_write_section): Add relocations in relocatable builds.
     (elf32_arm_count_additional_relocs): New function.
     (elf_backend_count_additional_relocs): New define.
     * bfd/elflink.c (bfd_elf_final_link): Use callback and adjust size of
     .rel section.
     * bfd/elfxx-target.h (elf_backend_count_additional_relocs): New define.

ld   * emultempl/armelf.em (gld${EMULATION_NAME}_after_allocation): Call
     elf32_arm_fix_exidx_coverage for relocatable builds.

ld/testsuite
     * ld-arm/arm-elf.exp: New test.
     * ld-arm/unwind-rel.d: New file.
     * ld-arm/unwind-rel1.s: New file.
     * ld-arm/unwind-rel2.s: New file.
     * ld-arm/unwind-rel3.s: New file.

8 files changed, 117 insertions, 46 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 576e3dc..a7014d5 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2015-12-22 Yury Usishchev <y.usishchev@samsung.com>
+
+	* emultempl/armelf.em (gld${EMULATION_NAME}_after_allocation): Call
+	elf32_arm_fix_exidx_coverage for relocatable builds.
+
 2015-12-10  Kwok Cheung Yeung  <kcy@codesourcery.com>
 
 	PR ld/18199
diff --git a/ld/emultempl/armelf.em b/ld/emultempl/armelf.em
index 2931a49..aae45d1 100644
--- a/ld/emultempl/armelf.em
+++ b/ld/emultempl/armelf.em
@@ -293,55 +293,52 @@ gld${EMULATION_NAME}_after_allocation (void)
 {
   int ret;
 
-  if (!bfd_link_relocatable (&link_info))
+  /* Build a sorted list of input text sections, then use that to process
+     the unwind table index.  */
+  unsigned int list_size = 10;
+  asection **sec_list = (asection **)
+      xmalloc (list_size * sizeof (asection *));
+  unsigned int sec_count = 0;
+
+  LANG_FOR_EACH_INPUT_STATEMENT (is)
     {
-      /* Build a sorted list of input text sections, then use that to process
-	 the unwind table index.  */
-      unsigned int list_size = 10;
-      asection **sec_list = (asection **)
-          xmalloc (list_size * sizeof (asection *));
-      unsigned int sec_count = 0;
+      bfd *abfd = is->the_bfd;
+      asection *sec;
 
-      LANG_FOR_EACH_INPUT_STATEMENT (is)
-	{
-	  bfd *abfd = is->the_bfd;
-	  asection *sec;
+      if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
+	continue;
 
-	  if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
-	    continue;
-
-	  for (sec = abfd->sections; sec != NULL; sec = sec->next)
+      for (sec = abfd->sections; sec != NULL; sec = sec->next)
+	{
+	  asection *out_sec = sec->output_section;
+
+	  if (out_sec
+	      && elf_section_data (sec)
+	      && elf_section_type (sec) == SHT_PROGBITS
+	      && (elf_section_flags (sec) & SHF_EXECINSTR) != 0
+	      && (sec->flags & SEC_EXCLUDE) == 0
+	      && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
+	      && out_sec != bfd_abs_section_ptr)
 	    {
-	      asection *out_sec = sec->output_section;
-
-	      if (out_sec
-		  && elf_section_data (sec)
-		  && elf_section_type (sec) == SHT_PROGBITS
-		  && (elf_section_flags (sec) & SHF_EXECINSTR) != 0
-		  && (sec->flags & SEC_EXCLUDE) == 0
-		  && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS
-		  && out_sec != bfd_abs_section_ptr)
+	      if (sec_count == list_size)
 		{
-		  if (sec_count == list_size)
-		    {
-		      list_size *= 2;
-		      sec_list = (asection **)
-                          xrealloc (sec_list, list_size * sizeof (asection *));
-		    }
-
-		  sec_list[sec_count++] = sec;
+		  list_size *= 2;
+		  sec_list = (asection **)
+		      xrealloc (sec_list, list_size * sizeof (asection *));
 		}
+
+	      sec_list[sec_count++] = sec;
 	    }
 	}
+    }
 
-      qsort (sec_list, sec_count, sizeof (asection *), &compare_output_sec_vma);
+  qsort (sec_list, sec_count, sizeof (asection *), &compare_output_sec_vma);
 
-      if (elf32_arm_fix_exidx_coverage (sec_list, sec_count, &link_info,
-					   merge_exidx_entries))
-	need_laying_out = 1;
+  if (elf32_arm_fix_exidx_coverage (sec_list, sec_count, &link_info,
+				    merge_exidx_entries))
+    need_laying_out = 1;
 
-      free (sec_list);
-    }
+  free (sec_list);
 
   /* bfd_elf32_discard_info just plays with debugging sections,
      ie. doesn't affect any code, so we can delay resizing the
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index d5982b9..d8b2d3c 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,14 +1,22 @@
+2015-12-21 Yury Usishchev <y.usishchev@samsung.com>
+
+	* ld-arm/arm-elf.exp: New test.
+	* ld-arm/unwind-rel.d: New file.
+	* ld-arm/unwind-rel1.s: New file.
+	* ld-arm/unwind-rel2.s: New file.
+	* ld-arm/unwind-rel3.s: New file.
+
 2015-12-22 Mickael Guene <mickael.guene@st.com>
 
 	* ld-arm/arm-elf.exp: New tests.
-	* ld-arm/thumb1-input-section-flag-match.d: New
-	* ld-arm/thumb1-input-section-flag-match.s: New
-	* ld-arm/thumb1-noread-not-present-mixing-two-section.d: New
-	* ld-arm/thumb1-noread-not-present-mixing-two-section.s: New
-	* ld-arm/thumb1-noread-present-one-section.d: New
-	* ld-arm/thumb1-noread-present-one-section.s: New
-	* ld-arm/thumb1-noread-present-two-section.d: New
-	* ld-arm/thumb1-noread-present-two-section.s: New
+	* ld-arm/thumb1-input-section-flag-match.d: New.
+	* ld-arm/thumb1-input-section-flag-match.s: New.
+	* ld-arm/thumb1-noread-not-present-mixing-two-section.d: New.
+	* ld-arm/thumb1-noread-not-present-mixing-two-section.s: New.
+	* ld-arm/thumb1-noread-present-one-section.d: New.
+	* ld-arm/thumb1-noread-present-one-section.s: New.
+	* ld-arm/thumb1-noread-present-two-section.d: New.
+	* ld-arm/thumb1-noread-present-two-section.s: New.
 
 2015-12-16  Mickael Guene <mickael.guene@st.com>
 
diff --git a/ld/testsuite/ld-arm/arm-elf.exp b/ld/testsuite/ld-arm/arm-elf.exp
index a970dba..ac2abf1 100644
--- a/ld/testsuite/ld-arm/arm-elf.exp
+++ b/ld/testsuite/ld-arm/arm-elf.exp
@@ -941,3 +941,9 @@ run_dump_test "gc-hidden-1"
 run_dump_test "protected-data"
 run_dump_test "stm32l4xx-cannot-fix-it-block"
 run_dump_test "stm32l4xx-cannot-fix-far-ldm"
+set arm_unwind_tests {
+    {"unwind-rel" "-r -Tarm.ld" "" "" {unwind-rel1.s unwind-rel2.s unwind-rel3.s}
+     {{readelf -ur unwind-rel.d}}
+     "unwind-rel"}
+}
+run_ld_link_tests $arm_unwind_tests
diff --git a/ld/testsuite/ld-arm/unwind-rel.d b/ld/testsuite/ld-arm/unwind-rel.d
new file mode 100644
index 0000000..b2aa6e2
--- /dev/null
+++ b/ld/testsuite/ld-arm/unwind-rel.d
@@ -0,0 +1,31 @@
+
+Relocation section '\.rel\.text' at offset .* contains 3 entries:
+ Offset     Info    Type            Sym\.Value  Sym\. Name
+00000000  00000028 R_ARM_V4BX       
+00000004  00000028 R_ARM_V4BX       
+00000008  00000028 R_ARM_V4BX       
+
+Relocation section '\.rel\.ARM\.exidx' at offset .* contains 5 entries:
+ Offset     Info    Type            Sym\.Value  Sym\. Name
+00000000  0000012a R_ARM_PREL31      00000000   \.text
+00000000  00000e00 R_ARM_NONE        00000000   __aeabi_unwind_cpp_pr0
+00000008  0000012a R_ARM_PREL31      00000000   \.text
+00000010  0000012a R_ARM_PREL31      00000000   \.text
+00000010  00000e00 R_ARM_NONE        00000000   __aeabi_unwind_cpp_pr0
+
+Unwind table index '\.ARM\.exidx' at offset .* contains 3 entries:
+
+0x0: 0x80a8b0b0
+  Compact model index: 0
+  0xa8      pop {r4, r14}
+  0xb0      finish
+  0xb0      finish
+
+0x4 <test>: 0x1 \[cantunwind\]
+
+0x8 <end>: 0x80a8b0b0
+  Compact model index: 0
+  0xa8      pop {r4, r14}
+  0xb0      finish
+  0xb0      finish
+
diff --git a/ld/testsuite/ld-arm/unwind-rel1.s b/ld/testsuite/ld-arm/unwind-rel1.s
new file mode 100644
index 0000000..9efb78b
--- /dev/null
+++ b/ld/testsuite/ld-arm/unwind-rel1.s
@@ -0,0 +1,9 @@
+	.syntax unified
+	.text
+	.global _start
+	.type _start, %function
+_start:
+	.fnstart
+	.save {r4, lr}
+	bx lr
+	.fnend
diff --git a/ld/testsuite/ld-arm/unwind-rel2.s b/ld/testsuite/ld-arm/unwind-rel2.s
new file mode 100644
index 0000000..1001743
--- /dev/null
+++ b/ld/testsuite/ld-arm/unwind-rel2.s
@@ -0,0 +1,6 @@
+	.syntax unified
+	.text
+	.global test
+	.type test, %function
+test:
+	bx lr
diff --git a/ld/testsuite/ld-arm/unwind-rel3.s b/ld/testsuite/ld-arm/unwind-rel3.s
new file mode 100644
index 0000000..8511339
--- /dev/null
+++ b/ld/testsuite/ld-arm/unwind-rel3.s
@@ -0,0 +1,9 @@
+	.syntax unified
+	.text
+	.global end
+	.type end, %function
+end:
+	.fnstart
+	.save {r4, lr}
+	bx lr
+	.fnend