Add support for linking ARMv8-M object files

2015-12-24  Thomas Preud'homme  <thomas.preudhomme@arm.com>

bfd/
    * elf32-arm.c (using_thumb_only): Check that profile is 'M' and update
    logic around Tag_CPU_arch values to return TRUE for ARMv8-M
    architectures.
    (tag_cpu_arch_combine): Define v8m_baseline and v8m_mainline and update
    v4t_plus_v6_m and comb to deal with ARMv8-M Tag_CPU_arch merging logic.
    (elf32_arm_merge_eabi_attributes): Add Tag_CPU_name values for
    ARMv8-M.

bfd/testsuite/
    * ld-arm/arm-elf.exp (armeabitests_common): Run new tests
    "Thumb-Thumb farcall v8-M", "EABI attribute merging 8",
    "EABI attribute merging 9" and "EABI attribute merging 10".
    (Thumb-Thumb farcall v8-M): Renamed to ...
    (Thumb-Thumb farcall v8-M Mainline): This.
    (Thumb-Thumb farcall v8-M Baseline): New test.
    * ld-arm/attr-merge-8a.s: New file.
    * ld-arm/attr-merge-8b.s: Likewise.
    * ld-arm/attr-merge-8.attr: Likewise.
    * ld-arm/attr-merge-9a.s: Likewise.
    * ld-arm/attr-merge-9b.s: Likewise.
    * ld-arm/attr-merge-9.out: Likewise.
    * ld-arm/attr-merge-10a.s: Likewise.
    * ld-arm/attr-merge-10b.s: Likewise.
    * ld-arm/attr-merge-10.attr: Likewise.

13 files changed, 149 insertions, 15 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 65e9bfb..a3f3a6c 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,15 @@
 2015-12-24  Thomas Preud'homme  <thomas.preudhomme@arm.com>
 
+	* elf32-arm.c (using_thumb_only): Check that profile is 'M' and update
+	logic around Tag_CPU_arch values to return TRUE for ARMv8-M
+	architectures.
+	(tag_cpu_arch_combine): Define v8m_baseline and v8m_mainline and update
+	v4t_plus_v6_m and comb to deal with ARMv8-M Tag_CPU_arch merging logic.
+	(elf32_arm_merge_eabi_attributes): Add Tag_CPU_name values for
+	ARMv8-M.
+
+2015-12-24  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
 	(tag_cpu_arch_combine): Adjust comment in v4t_plus_v6_m with regards
 	to merging with ARMv8-M Baseline.
 
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index 415090f..f350dd9 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -3504,20 +3504,23 @@ create_ifunc_sections (struct bfd_link_info *info)
 static bfd_boolean
 using_thumb_only (struct elf32_arm_link_hash_table *globals)
 {
-  int arch = bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
-				       Tag_CPU_arch);
-  int profile;
+  int arch;
+  int profile = bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
+					  Tag_CPU_arch_profile);
 
-  if (arch == TAG_CPU_ARCH_V6_M || arch == TAG_CPU_ARCH_V6S_M)
-    return TRUE;
+  if (profile)
+    return profile == 'M';
 
-  if (arch != TAG_CPU_ARCH_V7 && arch != TAG_CPU_ARCH_V7E_M)
-    return FALSE;
+  arch = bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC, Tag_CPU_arch);
 
-  profile = bfd_elf_get_obj_attr_int (globals->obfd, OBJ_ATTR_PROC,
-				      Tag_CPU_arch_profile);
+  if (arch == TAG_CPU_ARCH_V6_M
+      || arch == TAG_CPU_ARCH_V6S_M
+      || arch == TAG_CPU_ARCH_V7E_M
+      || arch == TAG_CPU_ARCH_V8M_BASE
+      || arch == TAG_CPU_ARCH_V8M_MAIN)
+    return TRUE;
 
-  return profile == 'M';
+  return FALSE;
 }
 
 /* Determine if we're dealing with a Thumb-2 object.  */
@@ -12275,6 +12278,47 @@ tag_cpu_arch_combine (bfd *ibfd, int oldtag, int *secondary_compat_out,
       T(V8),		/* V7E_M.  */
       T(V8)		/* V8.  */
     };
+  const int v8m_baseline[] =
+    {
+      -1,		/* PRE_V4.  */
+      -1,		/* V4.  */
+      -1,		/* V4T.  */
+      -1,		/* V5T.  */
+      -1,		/* V5TE.  */
+      -1,		/* V5TEJ.  */
+      -1,		/* V6.  */
+      -1,		/* V6KZ.  */
+      -1,		/* V6T2.  */
+      -1,		/* V6K.  */
+      -1,		/* V7.  */
+      T(V8M_BASE),	/* V6_M.  */
+      T(V8M_BASE),	/* V6S_M.  */
+      -1,		/* V7E_M.  */
+      -1,		/* V8.  */
+      -1,
+      T(V8M_BASE)	/* V8-M BASELINE.  */
+    };
+  const int v8m_mainline[] =
+    {
+      -1,		/* PRE_V4.  */
+      -1,		/* V4.  */
+      -1,		/* V4T.  */
+      -1,		/* V5T.  */
+      -1,		/* V5TE.  */
+      -1,		/* V5TEJ.  */
+      -1,		/* V6.  */
+      -1,		/* V6KZ.  */
+      -1,		/* V6T2.  */
+      -1,		/* V6K.  */
+      T(V8M_MAIN),	/* V7.  */
+      T(V8M_MAIN),	/* V6_M.  */
+      T(V8M_MAIN),	/* V6S_M.  */
+      T(V8M_MAIN),	/* V7E_M.  */
+      -1,		/* V8.  */
+      -1,
+      T(V8M_MAIN),	/* V8-M BASELINE.  */
+      T(V8M_MAIN)	/* V8-M MAINLINE.  */
+    };
   const int v4t_plus_v6_m[] =
     {
       -1,		/* PRE_V4.  */
@@ -12293,8 +12337,8 @@ tag_cpu_arch_combine (bfd *ibfd, int oldtag, int *secondary_compat_out,
       T(V7E_M),		/* V7E_M.  */
       T(V8),		/* V8.  */
       -1,		/* Unused.  */
-      -1,		/* V8-M BASELINE.  */
-      -1,		/* V8-M MAINLINE.  */
+      T(V8M_BASE),	/* V8-M BASELINE.  */
+      T(V8M_MAIN),	/* V8-M MAINLINE.  */
       T(V4T_PLUS_V6_M)	/* V4T plus V6_M.  */
     };
   const int *comb[] =
@@ -12307,8 +12351,8 @@ tag_cpu_arch_combine (bfd *ibfd, int oldtag, int *secondary_compat_out,
       v7e_m,
       v8,
       NULL,
-      NULL,
-      NULL,
+      v8m_baseline,
+      v8m_mainline,
       /* Pseudo-architecture.  */
       v4t_plus_v6_m
     };
@@ -12524,7 +12568,10 @@ elf32_arm_merge_eabi_attributes (bfd *ibfd, bfd *obfd)
 		"ARM v7",
 		"ARM v6-M",
 		"ARM v6S-M",
-		"ARM v8"
+		"ARM v8",
+		"",
+		"ARM v8-M.baseline",
+		"ARM v8-M.mainline",
 	    };
 
 	    /* Merge Tag_CPU_arch and Tag_also_compatible_with.  */
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index d8b2d3c..879aab4 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,21 @@
+2015-12-24  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	* ld-arm/arm-elf.exp (armeabitests_common): Run new tests
+	"Thumb-Thumb farcall v8-M", "EABI attribute merging 8",
+	"EABI attribute merging 9" and "EABI attribute merging 10".
+	(Thumb-Thumb farcall v8-M): Renamed to ...
+	(Thumb-Thumb farcall v8-M Mainline): This.
+	(Thumb-Thumb farcall v8-M Baseline): New test.
+	* ld-arm/attr-merge-8a.s: New file.
+	* ld-arm/attr-merge-8b.s: Likewise.
+	* ld-arm/attr-merge-8.attr: Likewise.
+	* ld-arm/attr-merge-9a.s: Likewise.
+	* ld-arm/attr-merge-9b.s: Likewise.
+	* ld-arm/attr-merge-9.out: Likewise.
+	* ld-arm/attr-merge-10a.s: Likewise.
+	* ld-arm/attr-merge-10b.s: Likewise.
+	* ld-arm/attr-merge-10.attr: Likewise.
+
 2015-12-21 Yury Usishchev <y.usishchev@samsung.com>
 
 	* ld-arm/arm-elf.exp: New test.
diff --git a/ld/testsuite/ld-arm/arm-elf.exp b/ld/testsuite/ld-arm/arm-elf.exp
index ac2abf1..724e338 100644
--- a/ld/testsuite/ld-arm/arm-elf.exp
+++ b/ld/testsuite/ld-arm/arm-elf.exp
@@ -388,6 +388,15 @@ set armeabitests_common {
      {"EABI attribute merging 7" "-r" "" "" {attr-merge-7a.s attr-merge-7b.s}
       {{readelf -A attr-merge-7.attr}}
       "attr-merge-7"}
+     {"EABI attribute merging 8" "-r" "" "" {attr-merge-8a.s attr-merge-8b.s}
+      {{readelf -A attr-merge-8.attr}}
+      "attr-merge-8"}
+     {"EABI attribute merging 9" "-r" "" "" {attr-merge-9a.s attr-merge-9b.s}
+      {{ld attr-merge-9.out}}
+      "attr-merge-9"}
+     {"EABI attribute merging 10" "-r" "" "" {attr-merge-10a.s attr-merge-10b.s}
+      {{readelf -A attr-merge-10.attr}}
+      "attr-merge-10"}
      {"EABI attribute arch merging 1" "-r" "" "" {arch-v6k.s arch-v6t2.s}
       {{readelf -A attr-merge-arch-1.attr}}
       "attr-merge-arch-1"}
@@ -451,6 +460,12 @@ set armeabitests_nonacl {
     {"Thumb-Thumb farcall M profile" "-Ttext 0x1000 --section-start .foo=0x2001014" "" "-march=armv7-m" {farcall-thumb-thumb.s}
      {{objdump -d farcall-thumb-thumb-m.d}}
      "farcall-thumb-thumb-m"}
+    {"Thumb-Thumb farcall v8-M Baseline" "-Ttext 0x1000 --section-start .foo=0x2001014" "" "-march=armv8-m.base" {farcall-thumb-thumb.s}
+     {{objdump -d farcall-thumb-thumb-m.d}}
+     "farcall-thumb-thumb-v8-m-base"}
+    {"Thumb-Thumb farcall v8-M Mainline" "-Ttext 0x1000 --section-start .foo=0x2001014" "" "-march=armv8-m.main" {farcall-thumb-thumb.s}
+     {{objdump -d farcall-thumb-thumb-m.d}}
+     "farcall-thumb-thumb-v8-m-main"}
     {"Thumb-Thumb farcall v6-M" "-Ttext 0x1000 --section-start .foo=0x2001014" "" "-march=armv6-m" {farcall-thumb-thumb.s}
      {{objdump -d farcall-thumb-thumb-m.d}}
      "farcall-thumb-thumb-v6-m"}
diff --git a/ld/testsuite/ld-arm/attr-merge-10.attr b/ld/testsuite/ld-arm/attr-merge-10.attr
new file mode 100644
index 0000000..3d4e82c
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-10.attr
@@ -0,0 +1,6 @@
+Attribute Section: aeabi
+File Attributes
+  Tag_CPU_name: "8-M.MAIN"
+  Tag_CPU_arch: v8-M.mainline
+  Tag_CPU_arch_profile: Microcontroller
+  Tag_THUMB_ISA_use: Yes
diff --git a/ld/testsuite/ld-arm/attr-merge-10a.s b/ld/testsuite/ld-arm/attr-merge-10a.s
new file mode 100644
index 0000000..faff6bd
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-10a.s
@@ -0,0 +1,5 @@
+	.arch armv8-m.base
+
+	@ Tag_CPU_arch & Tag_CPU_arch_profile = v8-M.BASE
+	.eabi_attribute Tag_CPU_arch, 16
+	.eabi_attribute Tag_CPU_arch_profile, 'M'
diff --git a/ld/testsuite/ld-arm/attr-merge-10b.s b/ld/testsuite/ld-arm/attr-merge-10b.s
new file mode 100644
index 0000000..68625d3
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-10b.s
@@ -0,0 +1,5 @@
+	.arch armv8-m.main
+
+	@ Tag_CPU_arch & Tag_CPU_arch_profile = v8-M.MAIN
+	.eabi_attribute Tag_CPU_arch, 17
+	.eabi_attribute Tag_CPU_arch_profile, 'M'
diff --git a/ld/testsuite/ld-arm/attr-merge-8.attr b/ld/testsuite/ld-arm/attr-merge-8.attr
new file mode 100644
index 0000000..7f922ac
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-8.attr
@@ -0,0 +1,6 @@
+Attribute Section: aeabi
+File Attributes
+  Tag_CPU_name: "8-M.BASE"
+  Tag_CPU_arch: v8-M.baseline
+  Tag_CPU_arch_profile: Microcontroller
+  Tag_THUMB_ISA_use: Yes
diff --git a/ld/testsuite/ld-arm/attr-merge-8a.s b/ld/testsuite/ld-arm/attr-merge-8a.s
new file mode 100644
index 0000000..fc5ea8b
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-8a.s
@@ -0,0 +1,5 @@
+	.arch armv6-m
+
+	@ Tag_CPU_arch & Tag_CPU_arch_profile = v6-M
+	.eabi_attribute Tag_CPU_arch, 11
+	.eabi_attribute Tag_CPU_arch_profile, 'M'
diff --git a/ld/testsuite/ld-arm/attr-merge-8b.s b/ld/testsuite/ld-arm/attr-merge-8b.s
new file mode 100644
index 0000000..8ee553a
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-8b.s
@@ -0,0 +1,5 @@
+	.arch armv8-m.base
+
+	@ Tag_CPU_arch & Tag_CPU_arch_profile = v8-M Baseline
+	.eabi_attribute Tag_CPU_arch, 16
+	.eabi_attribute Tag_CPU_arch_profile, 'M'
diff --git a/ld/testsuite/ld-arm/attr-merge-9.out b/ld/testsuite/ld-arm/attr-merge-9.out
new file mode 100644
index 0000000..bb09181
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-9.out
@@ -0,0 +1,2 @@
+.*: error: .*: Conflicting CPU architectures 10/16
+.*: failed to merge target specific data of file tmpdir/attr-merge-9b.o
diff --git a/ld/testsuite/ld-arm/attr-merge-9a.s b/ld/testsuite/ld-arm/attr-merge-9a.s
new file mode 100644
index 0000000..0e24017
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-9a.s
@@ -0,0 +1,5 @@
+	.arch armv7-m
+
+	@ Tag_CPU_arch & Tag_CPU_arch_profile = v7-M
+	.eabi_attribute Tag_CPU_arch, 10
+	.eabi_attribute Tag_CPU_arch_profile, 'M'
diff --git a/ld/testsuite/ld-arm/attr-merge-9b.s b/ld/testsuite/ld-arm/attr-merge-9b.s
new file mode 100644
index 0000000..8ee553a
--- /dev/null
+++ b/ld/testsuite/ld-arm/attr-merge-9b.s
@@ -0,0 +1,5 @@
+	.arch armv8-m.base
+
+	@ Tag_CPU_arch & Tag_CPU_arch_profile = v8-M Baseline
+	.eabi_attribute Tag_CPU_arch, 16
+	.eabi_attribute Tag_CPU_arch_profile, 'M'