Add new plugin hooks to support querying section alignment and size.

include/
2016-03-03  Than McIntosh <thanm@google.com>

	* plugin-api.h: Add new hooks to the plugin transfer vector to
	to support querying section alignment and section size.
	(ld_plugin_get_input_section_alignment): New hook.
	(ld_plugin_get_input_section_size): New hook.
	(ld_plugin_tag): Add LDPT_GET_INPUT_SECTION_ALIGNMENT
	and LDPT_GET_INPUT_SECTION_SIZE.
	(ld_plugin_tv): Add tv_get_input_section_alignment and
	tv_get_input_section_size.

gold/
2016-03-03  Than McIntosh  <thanm@google.com>

	* plugin.cc (Plugin::load): Include hooks for get_input_section_size
	and get_input_section_alignment in transfer vector.
	(get_input_section_alignment): New function.
	(get_input_section_size): New function.
	* testsuite/Makefile.am: Add plugin_layout_with_alignment.sh test.
	* testsuite/Makefile.in: [Regenerate.]
	* testsuite/plugin_section_alignment.cc: New test file.
	* testsuite/plugin_layout_with_alignment.cc: New test file.
	* testsuite/plugin_layout_with_alignment.sh: New test file.

1 files changed, 25 insertions, 1 deletions

diff --git a/include/plugin-api.h b/include/plugin-api.h
index 811e6e4..a794a37 100644
--- a/include/plugin-api.h
+++ b/include/plugin-api.h
@@ -345,6 +345,26 @@ enum ld_plugin_status
     const struct ld_plugin_section * section_list,
     unsigned int num_sections);
 
+/* The linker's interface for retrieving the section alignment requirement
+   of a specific section in an object.  This interface should only be invoked in the
+   claim_file handler.  This function sets *ADDRALIGN to the ELF sh_addralign
+   value of the input section.  */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_get_input_section_alignment) (const struct ld_plugin_section section,
+                                          unsigned int *addralign);
+
+/* The linker's interface for retrieving the section size of a specific section
+   in an object.  This interface should only be invoked in the claim_file handler.
+   This function sets *SECSIZE to the ELF sh_size
+   value of the input section.  */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_get_input_section_size) (const struct ld_plugin_section section,
+                                     uint64_t *secsize);
+
 enum ld_plugin_level
 {
   LDPL_INFO,
@@ -385,7 +405,9 @@ enum ld_plugin_tag
   LDPT_GET_SYMBOLS_V2 = 25,
   LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS = 26,
   LDPT_UNIQUE_SEGMENT_FOR_SECTIONS = 27,
-  LDPT_GET_SYMBOLS_V3 = 28
+  LDPT_GET_SYMBOLS_V3 = 28,
+  LDPT_GET_INPUT_SECTION_ALIGNMENT = 29,
+  LDPT_GET_INPUT_SECTION_SIZE = 30
 };
 
 /* The plugin transfer vector.  */
@@ -417,6 +439,8 @@ struct ld_plugin_tv
     ld_plugin_allow_section_ordering tv_allow_section_ordering;
     ld_plugin_allow_unique_segment_for_sections tv_allow_unique_segment_for_sections; 
     ld_plugin_unique_segment_for_sections tv_unique_segment_for_sections;
+    ld_plugin_get_input_section_alignment tv_get_input_section_alignment;
+    ld_plugin_get_input_section_size tv_get_input_section_size;
   } tv_u;
 };