Add support for non-contiguous memory regions

2020-01-06  Christophe Lyon  <christophe.lyon@linaro.org>

	bfd/
	* bfd-in2.h: Regenerate.
	* section.c (asection): Add already_assigned field.
	(BFD_FAKE_SECTION): Add default initializer for it.
	* ecoff.c (bfd_debug_section): Initialize already_assigned field.
	* elf32-arm.c (arm_build_one_stub): Add support for
	non_contiguous_regions.
	* elf32-csky.c (csky_build_one_stub): Likewise.
	* elf32-hppa.c (hppa_build_one_stub): Likewise.
	* elf32-m68hc11.c (m68hc11_elf_build_one_stub): Likewise.
	* elf32-m68hc12.c (m68hc12_elf_build_one_stub): Likewise.
	* elf32-metag.c (metag_build_one_stub): Likewise.
	* elf32-nios2.c (nios2_build_one_stub): Likewise.
	* elf64-ppc.c (ppc_build_one_stub): Likewise.
	(ppc_size_one_stub): Likewise.
	* elfnn-aarch64.c (aarch64_build_one_stub): Likewise.
	* elflink.c (elf_link_input_bfd): Likewise.

	include/
	* bfdlink.h (bfd_link_info): Add non_contiguous_regions and
	non_contiguous_regions_warnings fields.

	ld/
	* ldlang.c (lang_add_section): Add support for
	non_contiguous_regions.
	(size_input_section): Likewise.
	(lang_size_sections_1): Likewise.
	(process_insert_statements): Likewise.
	* ldlex.h (option_values): Add OPTION_NON_CONTIGUOUS_REGIONS and
	OPTION_NON_CONTIGUOUS_REGIONS_WARNINGS.
	* lexsup.c (ld_options): Add entries for
	--enable-non-contiguous-regions and
	--enable-non-contiguous-regions-warnings.
	(parse_args): Handle it.
	* NEWS: Add --enable-non-contiguous-regions and
	--enable-non-contiguous-regions-warnings.
	* ld.texi: Add --enable-non-contiguous-regions and
	--enable-non-contiguous-regions-warnings documentation.
	* emultempl/armelf.em (elf32_arm_add_stub_section): Add
	SEC_LINKER_CREATED flag.
	* emultempl/xtensaelf.em (ld_build_required_section_dependence):
	Emit an error when --enable-non-contiguous-regions is used.
	* testsuite/ld-elf/non-contiguous.d: New.
	* testsuite/ld-elf/non-contiguous.ld: New.
	* testsuite/ld-elf/non-contiguous.s: New.
	* testsuite/ld-arm/arm-elf.exp: Run the new tests.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm.s: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm.d: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm.ld: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm2.d: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm3.ld: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm3.d: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm3.ld: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm4.d: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm4.ld: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm5.d: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm5.ld: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm6.d: New.
	* testsuite/ld-arm/arm-elf/non-contiguous-arm6.ld: New.
	* testsuite/ld-powerpc/powerpc.exp: Run new tests.
	* testsuite/ld-powerpc/non-contiguous-powerpc.d: New.
	* testsuite/ld-powerpc/non-contiguous-powerpc.ld: New.
	* testsuite/ld-powerpc/non-contiguous-powerpc.sd: New.
	* testsuite/ld-powerpc/non-contiguous-powerpc64.d: New.

14 files changed, 218 insertions, 6 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 8b09093..84bc1e1 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,22 @@
+2020-03-13  Christophe Lyon  <christophe.lyon@linaro.org>
+
+	* bfd-in2.h: Regenerate.
+	* section.c (asection): Add already_assigned field.
+	(BFD_FAKE_SECTION): Add default initializer for it.
+	* ecoff.c (bfd_debug_section): Initialize already_assigned field.
+	* elf32-arm.c (arm_build_one_stub): Add support for
+	non_contiguous_regions.
+	* elf32-csky.c (csky_build_one_stub): Likewise.
+	* elf32-hppa.c (hppa_build_one_stub): Likewise.
+	* elf32-m68hc11.c (m68hc11_elf_build_one_stub): Likewise.
+	* elf32-m68hc12.c (m68hc12_elf_build_one_stub): Likewise.
+	* elf32-metag.c (metag_build_one_stub): Likewise.
+	* elf32-nios2.c (nios2_build_one_stub): Likewise.
+	* elf64-ppc.c (ppc_build_one_stub): Likewise.
+	(ppc_size_one_stub): Likewise.
+	* elfnn-aarch64.c (aarch64_build_one_stub): Likewise.
+	* elflink.c (elf_link_input_bfd): Likewise.
+
 2020-03-13  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR ld/24920
diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index 3711460..9859e51 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -1192,6 +1192,10 @@ typedef struct bfd_section
     struct bfd_section *s;
     const char *linked_to_symbol_name;
   } map_head, map_tail;
+ /* Points to the output section this section is already assigned to, if any.
+    This is used when support for non-contiguous memory regions is enabled.  */
+ struct bfd_section *already_assigned;
+
 } asection;
 
 /* Relax table contains information about instructions which can
@@ -1373,7 +1377,10 @@ discarded_section (const asection *sec)
      (struct bfd_symbol *) SYM, &SEC.symbol,                           \
                                                                        \
   /* map_head, map_tail                                            */  \
-     { NULL }, { NULL }                                                \
+     { NULL }, { NULL },                                               \
+                                                                       \
+  /* already_assigned                                              */  \
+     NULL                                                              \
     }
 
 /* We use a macro to initialize the static asymbol structures because
diff --git a/bfd/ecoff.c b/bfd/ecoff.c
index 84eab99..ce8eb89 100644
--- a/bfd/ecoff.c
+++ b/bfd/ecoff.c
@@ -78,8 +78,10 @@ static asection bfd_debug_section =
      NULL,
   /* symbol_ptr_ptr,						   */
      NULL,
-  /* map_head, map_tail						   */
-     { NULL }, { NULL }
+  /* map_head, map_tail,					   */
+     { NULL }, { NULL },
+  /* already_assigned 						   */
+     NULL,
 };
 
 /* Create an ECOFF object.  */
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index c899aeb..e8b2ac4 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -5064,6 +5064,17 @@ arm_build_one_stub (struct bfd_hash_entry *gen_entry,
   stub_entry = (struct elf32_arm_stub_hash_entry *) gen_entry;
   info = (struct bfd_link_info *) in_arg;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
   globals = elf32_arm_hash_table (info);
   if (globals == NULL)
     return FALSE;
diff --git a/bfd/elf32-csky.c b/bfd/elf32-csky.c
index 6cf63f5..8415f7c 100644
--- a/bfd/elf32-csky.c
+++ b/bfd/elf32-csky.c
@@ -3621,6 +3621,17 @@ csky_build_one_stub (struct bfd_hash_entry *gen_entry,
   stub_entry = (struct elf32_csky_stub_hash_entry *)gen_entry;
   info = (struct bfd_link_info *) in_arg;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
   globals = csky_elf_hash_table (info);
   if (globals == NULL)
     return FALSE;
diff --git a/bfd/elf32-hppa.c b/bfd/elf32-hppa.c
index b1b0f82..9760b75 100644
--- a/bfd/elf32-hppa.c
+++ b/bfd/elf32-hppa.c
@@ -731,6 +731,17 @@ hppa_build_one_stub (struct bfd_hash_entry *bh, void *in_arg)
   switch (hsh->stub_type)
     {
     case hppa_stub_long_branch:
+      /* Fail if the target section could not be assigned to an output
+	 section.  The user should fix his linker script.  */
+      if (hsh->target_section->output_section == NULL
+	  && info->non_contiguous_regions)
+	{
+	  _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+				"Retry without --enable-non-contiguous-regions.\n"),
+			      hsh->target_section);
+	  abort();
+    }
+
       /* Create the long branch.  A long branch is formed with "ldil"
 	 loading the upper bits of the target address into a register,
 	 then branching with "be" which adds in the lower bits.
@@ -751,6 +762,16 @@ hppa_build_one_stub (struct bfd_hash_entry *bh, void *in_arg)
       break;
 
     case hppa_stub_long_branch_shared:
+      /* Fail if the target section could not be assigned to an output
+	 section.  The user should fix his linker script.  */
+      if (hsh->target_section->output_section == NULL
+	  && info->non_contiguous_regions)
+	{
+	  _bfd_error_handler (_("Could not assign %pA to an output section. "
+				"Retry without --enable-non-contiguous-regions.\n"),
+			      hsh->target_section);
+	  abort();
+    }
       /* Branches are relative.  This is where we are going to.  */
       sym_value = (hsh->target_value
 		   + hsh->target_section->output_offset
@@ -823,6 +844,16 @@ hppa_build_one_stub (struct bfd_hash_entry *bh, void *in_arg)
       break;
 
     case hppa_stub_export:
+      /* Fail if the target section could not be assigned to an output
+	 section.  The user should fix his linker script.  */
+      if (hsh->target_section->output_section == NULL
+	  && info->non_contiguous_regions)
+	{
+	  _bfd_error_handler (_("Could not assign %pA to an output section. "
+				"Retry without --enable-non-contiguous-regions.\n"),
+			      hsh->target_section);
+	  abort();
+    }
       /* Branches are relative.  This is where we are going to.  */
       sym_value = (hsh->target_value
 		   + hsh->target_section->output_offset
diff --git a/bfd/elf32-m68hc11.c b/bfd/elf32-m68hc11.c
index 8d4d227..3e12ae5 100644
--- a/bfd/elf32-m68hc11.c
+++ b/bfd/elf32-m68hc11.c
@@ -415,6 +415,17 @@ m68hc11_elf_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
   stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
   info = (struct bfd_link_info *) in_arg;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
   htab = m68hc11_elf_hash_table (info);
   if (htab == NULL)
     return FALSE;
diff --git a/bfd/elf32-m68hc12.c b/bfd/elf32-m68hc12.c
index e41b4c7..a04efd8 100644
--- a/bfd/elf32-m68hc12.c
+++ b/bfd/elf32-m68hc12.c
@@ -535,6 +535,17 @@ m68hc12_elf_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
   stub_entry = (struct elf32_m68hc11_stub_hash_entry *) gen_entry;
   info = (struct bfd_link_info *) in_arg;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
   htab = m68hc11_elf_hash_table (info);
 
   stub_sec = stub_entry->stub_sec;
diff --git a/bfd/elf32-metag.c b/bfd/elf32-metag.c
index 07e9856..3f30d6d 100644
--- a/bfd/elf32-metag.c
+++ b/bfd/elf32-metag.c
@@ -3459,7 +3459,7 @@ metag_type_of_stub (asection *input_sec,
 #define MOV_PC_A0_3	0xa3180ca0
 
 static bfd_boolean
-metag_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg ATTRIBUTE_UNUSED)
+metag_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
 {
   struct elf_metag_stub_hash_entry *hsh;
   asection *stub_sec;
@@ -3467,9 +3467,22 @@ metag_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg ATTRIBUTE_U
   bfd_byte *loc;
   bfd_vma sym_value;
   int size;
+  struct bfd_link_info *info;
 
   /* Massage our args to the form they really have.  */
   hsh = (struct elf_metag_stub_hash_entry *) gen_entry;
+  info = (struct bfd_link_info *) in_arg;
+
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (hsh->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  hsh->target_section);
+      abort();
+    }
 
   stub_sec = hsh->stub_sec;
 
diff --git a/bfd/elf32-nios2.c b/bfd/elf32-nios2.c
index 2fcfe6f..8c8bc0c 100644
--- a/bfd/elf32-nios2.c
+++ b/bfd/elf32-nios2.c
@@ -2490,7 +2490,20 @@ nios2_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg ATTRIBUTE_U
     = (struct elf32_nios2_stub_hash_entry *) gen_entry;
   asection *stub_sec = hsh->stub_sec;
   bfd_vma sym_value;
+  struct bfd_link_info *info;
+
+  info = (struct bfd_link_info *) in_arg;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (hsh->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  hsh->target_section);
+      abort();
+    }
   /* Make a note of the offset within the stubs for this entry.  */
   hsh->stub_offset = stub_sec->size;
 
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index c804ab3..83eaadf 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -11362,6 +11362,31 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
   stub_entry = (struct ppc_stub_hash_entry *) gen_entry;
   info = in_arg;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section != NULL
+      && stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
+  /* Same for the group.  */
+  if (stub_entry->group->stub_sec != NULL
+      && stub_entry->group->stub_sec->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign group %pA target %pA to an "
+			    "output section. Retry without "
+			    "--enable-non-contiguous-regions.\n"),
+			  stub_entry->group->stub_sec,
+			  stub_entry->target_section);
+      abort();
+    }
+
   htab = ppc_hash_table (info);
   if (htab == NULL)
     return FALSE;
@@ -11887,6 +11912,31 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
   if (htab == NULL)
     return FALSE;
 
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section != NULL
+      && stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign %pA to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
+  /* Same for the group.  */
+  if (stub_entry->group->stub_sec != NULL
+      && stub_entry->group->stub_sec->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign group %pA target %pA to an "
+			    "output section. Retry without "
+			    "--enable-non-contiguous-regions.\n"),
+			  stub_entry->group->stub_sec,
+			  stub_entry->target_section);
+      abort();
+    }
+
   /* Make a note of the offset within the stubs for this entry.  */
   stub_entry->stub_offset = stub_entry->group->stub_sec->size;
 
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 5852844..589550e 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -10569,6 +10569,18 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
 	 discarding, we don't need to keep it.  */
       if (isym->st_shndx != SHN_UNDEF
 	  && isym->st_shndx < SHN_LORESERVE
+	  && isec->output_section == NULL
+	  && flinfo->info->non_contiguous_regions
+	  && flinfo->info->non_contiguous_regions_warnings)
+	{
+	  _bfd_error_handler (_("warning: --enable-non-contiguous-regions "
+				"discards section `%s' from '%s'\n"),
+			      isec->name, isec->owner->filename);
+	  continue;
+	}
+
+      if (isym->st_shndx != SHN_UNDEF
+	  && isym->st_shndx < SHN_LORESERVE
 	  && bfd_section_removed_from_list (output_bfd,
 					    isec->output_section))
 	continue;
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index ba3ad45..b00b6c4 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -3278,7 +3278,7 @@ _bfd_aarch64_add_stub_entry_after (const char *stub_name,
 
 static bfd_boolean
 aarch64_build_one_stub (struct bfd_hash_entry *gen_entry,
-			void *in_arg ATTRIBUTE_UNUSED)
+			void *in_arg)
 {
   struct elf_aarch64_stub_hash_entry *stub_entry;
   asection *stub_sec;
@@ -3291,10 +3291,24 @@ aarch64_build_one_stub (struct bfd_hash_entry *gen_entry,
   unsigned int template_size;
   const uint32_t *template;
   unsigned int i;
+  struct bfd_link_info *info;
 
   /* Massage our args to the form they really have.  */
   stub_entry = (struct elf_aarch64_stub_hash_entry *) gen_entry;
 
+  info = (struct bfd_link_info *) in_arg;
+
+  /* Fail if the target section could not be assigned to an output
+     section.  The user should fix his linker script.  */
+  if (stub_entry->target_section->output_section == NULL
+      && info->non_contiguous_regions)
+    {
+      _bfd_error_handler (_("Could not assign '%pA' to an output section. "
+			    "Retry without --enable-non-contiguous-regions.\n"),
+			  stub_entry->target_section);
+      abort();
+    }
+
   stub_sec = stub_entry->stub_sec;
 
   /* Make a note of the offset within the stubs for this entry.  */
diff --git a/bfd/section.c b/bfd/section.c
index 7de0a2d..eef118f 100644
--- a/bfd/section.c
+++ b/bfd/section.c
@@ -551,6 +551,10 @@ CODE_FRAGMENT
 .    struct bfd_section *s;
 .    const char *linked_to_symbol_name;
 .  } map_head, map_tail;
+. {* Points to the output section this section is already assigned to, if any.
+.    This is used when support for non-contiguous memory regions is enabled.  *}
+. struct bfd_section *already_assigned;
+.
 .} asection;
 .
 .{* Relax table contains information about instructions which can
@@ -732,7 +736,10 @@ CODE_FRAGMENT
 .     (struct bfd_symbol *) SYM, &SEC.symbol,				\
 .									\
 .  {* map_head, map_tail                                            *}	\
-.     { NULL }, { NULL }						\
+.     { NULL }, { NULL },						\
+.									\
+.  {* already_assigned                                             *}	\
+.     NULL								\
 .    }
 .
 .{* We use a macro to initialize the static asymbol structures because