Add support for creating ELF import libraries

2016-07-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>

bfd/
	* elf-bfd.h (elf_backend_filter_implib_symbols): Declare backend hook.
	(_bfd_elf_filter_global_symbols): Declare.
	* elf.c (_bfd_elf_filter_global_symbols): New function.
	* elflink.c (elf_filter_global_symbols): Likewise.
	(elf_output_implib): Likewise.
	(bfd_elf_final_link): Call above function, failing if it does.
	* elfxx-target.h (elf_backend_filter_implib_symbols): Define macro and
	default it to NULL.
	(elf_backend_copy_indirect_symbol): Fix spacing.
	(elf_backend_hide_symbol): Likewise.
	(elfNN_bed): Initialize elf_backend_filter_implib_symbols backend hook.

include/
	* bfdlink.h (struct bfd_link_info): Declare new ldscript_def and
	out_implib_bfd fields.

2016-07-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>
	    Nick Clifton  <nickc@redhat.com>

ld/
	* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Open import
	library file for writing and initialize implib_bfd field of link_info
	structure.
	* emultempl/pe.em (pe_implib_filename): Remove variable declaration.
	(OPTION_IMPLIB_FILENAME): Remove macro definition.
	(gld${EMULATION_NAME}_add_options): Remove --out-implib option.
	(gld_${EMULATION_NAME}_list_options): Likewise.
	(gld${EMULATION_NAME}_handle_option): Likewise.
	(gld_${EMULATION_NAME}_finish): Use command_line.out_implib_filename
	instead of pe_implib_filename.
	* emultempl/pep.em (pep_implib_filename): Remove variable declaration.
	(OPTION_IMPLIB_FILENAME): Remove enumerator.
	(gld${EMULATION_NAME}_add_options): Remove --out-implib option.
	(gld_${EMULATION_NAME}_list_options): Likewise.
	(gld${EMULATION_NAME}_handle_option): Likewise.
	(gld_${EMULATION_NAME}_finish): Use command_line.out_implib_filename
	instead of pep_implib_filename.
	* ld.h (args_type): Declare new out_implib_filename field.
	* ld.texinfo (--out-implib): Move documentation to arch-independent
	part and rephrase to apply to ELF targets.
	* ldexp.c (exp_fold_tree_1): Set ldscript_def field to 1 for symbols
	defined in linker scripts.
	* ldlex.h (enum option_values): Declare new OPTION_OUT_IMPLIB
	enumerator.
	* lexsup.c (ld_options): Add entry for new --out-implib switch.
	(parse_args): Handle OPTION_OUT_IMPLIB case.
	* testsuite/ld-elf/elf.exp (Generate empty import library): New test.
	(Generate import library): Likewise.
	* testsuite/ld-elf/implib.s: Likewise.
	* testsuite/ld-elf/implib.rd: New file.
	* testsuite/ld-elf/empty-implib.out: Likewise

4 files changed, 51 insertions, 0 deletions

diff --git a/ld/testsuite/ld-elf/elf.exp b/ld/testsuite/ld-elf/elf.exp
index 2dfd0e8..832f313 100644
--- a/ld/testsuite/ld-elf/elf.exp
+++ b/ld/testsuite/ld-elf/elf.exp
@@ -136,6 +136,22 @@ foreach t $test_list {
     run_dump_test [file rootname $t]
 }
 
+# Check that the --out-implib option work correctly.
+run_ld_link_tests {
+    {"Generate empty import library"
+     "--out-implib=tmpdir/implib.lib" ""
+     "--defsym NO_GLOBAL=1"
+     {implib.s}
+     {{ld empty-implib.out}}
+     "implib"}
+    {"Generate import library"
+     "-Tdata=0x1000 --out-implib=tmpdir/implib.lib" ""
+     ""
+     {implib.s}
+     {{readelf {-s tmpdir/implib.lib} implib.rd}}
+     "implib"}
+}
+
 if { [istarget *-*-linux*]
      || [istarget *-*-nacl*]
      || [istarget *-*-gnu*] } {
diff --git a/ld/testsuite/ld-elf/empty-implib.out b/ld/testsuite/ld-elf/empty-implib.out
new file mode 100644
index 0000000..b123064
--- /dev/null
+++ b/ld/testsuite/ld-elf/empty-implib.out
@@ -0,0 +1,2 @@
+.*: .*: no symbol found for import library
+.*: .*: failed to generate import library
diff --git a/ld/testsuite/ld-elf/implib.rd b/ld/testsuite/ld-elf/implib.rd
new file mode 100644
index 0000000..9f854a5
--- /dev/null
+++ b/ld/testsuite/ld-elf/implib.rd
@@ -0,0 +1,11 @@
+File: tmpdir/implib.lib
+
+Symbol table '.symtab' contains 3 entries:
+   Num:    Value +Size Type    Bind   Vis      Ndx Name
+     0: [0-9a-f]+     0 NOTYPE  LOCAL  DEFAULT  UND 
+     1: 0+100[0-3]     1 OBJECT  GLOBAL DEFAULT  ABS exported1
+     2: 0+100[0-3]     1 OBJECT  GLOBAL DEFAULT  ABS exported2
+
+File: tmpdir/implib
+
+#...
diff --git a/ld/testsuite/ld-elf/implib.s b/ld/testsuite/ld-elf/implib.s
new file mode 100644
index 0000000..a86a940
--- /dev/null
+++ b/ld/testsuite/ld-elf/implib.s
@@ -0,0 +1,22 @@
+.ifndef NO_GLOBAL
+	.bss
+	.comm	exported1,1
+
+	.data
+	.global	exported2
+	.type	exported2, %object
+	.size	exported2, 1
+exported2:
+	.byte	21
+.endif
+
+	.bss
+not_exported1:
+	.space	1
+	.size	not_exported1, 1
+
+	.data
+	.type	not_exported2, %object
+	.size	not_exported2, 1
+not_exported2:
+	.byte	42