[binutils-gdb] Make sure that undefined symbols added to the linker command line via the -u option appear in the ou

[Nick Clifton <nickc at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=66cae56016a12f7cbdc94be6f82c1cad1c59b521

commit 66cae56016a12f7cbdc94be6f82c1cad1c59b521
Author: Nick Clifton <nickc@redhat.com>
Date:   Mon Oct 23 18:16:49 2017 +0100

    Make sure that undefined symbols added to the linker command line via the -u option appear in the output executable, if they have not been resolved.
    
    	PR 22319
    bfd	* elflink.c (elf_link_output_extsym): Keep global undefined
    	symbols if they have been marked as needed.
    
    ld	* testsuite/ld-elf/pr22310.s: New test source file.
    	* testsuite/ld-elf/pr22310.d: New test driver.
    	* testsuite/ld-mmix/undef-3.d: Update expected output from readelf.

Diff:
---
 bfd/ChangeLog                  |  6 ++++++
 bfd/elflink.c                  |  3 +++
 ld/ChangeLog                   |  7 +++++++
 ld/testsuite/ld-elf/pr22319.d  |  9 +++++++++
 ld/testsuite/ld-elf/pr22319.s  |  2 ++
 ld/testsuite/ld-mmix/undef-3.d | 17 +++++++++--------
 6 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index fde334d..73d1f4b 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2017-10-23  Nick Clifton  <nickc@redhat.com>
+
+	PR 22319
+	* elflink.c (elf_link_output_extsym): Keep global undefined
+	symbols if they have been marked as needed.
+
 2017-10-23  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* elfn32-mips.c (mips_elf_n32_mkobject): New prototype and
diff --git a/bfd/elflink.c b/bfd/elflink.c
index b401e68..de13d04 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -9910,8 +9910,11 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
      relocatable output or when needed for --emit-relocs.  */
   else if (input_sec == bfd_und_section_ptr
 	   && h->indx != -2
+	   /* PR 22319 Do not strip global undefined symbols marked as being needed.  */
+	   && (h->mark != 1 || ELF_ST_BIND (sym.st_info) != STB_GLOBAL)
 	   && !bfd_link_relocatable (flinfo->info))
     return TRUE;
+
   /* Also strip others that we couldn't earlier due to dynamic symbol
      processing.  */
   if (strip)
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 041778e..24b6fa4 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,10 @@
+2017-10-23  Nick Clifton  <nickc@redhat.com>
+
+	PR 22310
+	* testsuite/ld-elf/pr22310.s: New test source file.
+	* testsuite/ld-elf/pr22310.d: New test driver.
+	* testsuite/ld-mmix/undef-3.d: Update expected output from readelf.
+
 2017-10-21  Hans-Peter Nilsson  <hp@axis.com>
 
 	PR ld/21233
diff --git a/ld/testsuite/ld-elf/pr22319.d b/ld/testsuite/ld-elf/pr22319.d
new file mode 100644
index 0000000..68a5706
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr22319.d
@@ -0,0 +1,9 @@
+#name: PR 22319 - required undefined symbols in output
+#ld: -u undefined_symbol -e 0
+#nm: -u
+#notarget: dlx-*-* 
+# The DLX target fails because it needs a special linker script to handle file symbols.
+
+[ 	]+U+[ 	]+undefined_symbol
+#pass
+
diff --git a/ld/testsuite/ld-elf/pr22319.s b/ld/testsuite/ld-elf/pr22319.s
new file mode 100644
index 0000000..5a02e47
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr22319.s
@@ -0,0 +1,2 @@
+	.data
+	.dc.b	0
diff --git a/ld/testsuite/ld-mmix/undef-3.d b/ld/testsuite/ld-mmix/undef-3.d
index 6afb52b..2484d76 100644
--- a/ld/testsuite/ld-mmix/undef-3.d
+++ b/ld/testsuite/ld-mmix/undef-3.d
@@ -12,20 +12,21 @@ Section Headers:
  +\[ 1\] \.text +PROGBITS +0+ +0+78
  +0+4 +0+ +AX +0 +0 +4
  +\[ 2\] \.symtab +SYMTAB +0+ .*
- +0+a8 +0+18 +3 +2 +8
+ +0+c0 +0+18 +3 +2 +8
  +\[ 3\] \.strtab +STRTAB +0+ .*
- +0+21 +0+ +0 +0 +1
+ +0+28 +0+ +0 +0 +1
  +\[ 4\] \.shstrtab +STRTAB +0+ +[0-9a-f]+
  +0+21 +0+ +0 +0 +1
 Key to Flags:
 #...
 
-Symbol table '\.symtab' contains 7 entries:
+Symbol table '\.symtab' contains 8 entries:
  +Num: +Value +Size +Type +Bind +Vis +Ndx +Name
  +0: 0+ +0 +NOTYPE +LOCAL +DEFAULT +UND 
  +1: 0+ +0 +SECTION +LOCAL +DEFAULT +1 
- +2: 0+ +0 +NOTYPE +GLOBAL +DEFAULT +1 _start
- +3: 2000000000000000 +0 +NOTYPE +GLOBAL +DEFAULT +1 __bss_start
- +4: 2000000000000000 +0 +NOTYPE +GLOBAL +DEFAULT +1 _edata
- +5: 2000000000000000 +0 +NOTYPE +GLOBAL +DEFAULT +1 _end
- +6: 0+ +0 +NOTYPE +GLOBAL +DEFAULT +1 _start\.
+[ 	]+2: 0+[ 	]+0[ 	]+NOTYPE[ 	]+GLOBAL[ 	]+DEFAULT[ 	]+UND[ 	]+undefd
+ +3: 0+ +0 +NOTYPE +GLOBAL +DEFAULT +1 _start
+ +4: 2000000000000000 +0 +NOTYPE +GLOBAL +DEFAULT +1 __bss_start
+ +5: 2000000000000000 +0 +NOTYPE +GLOBAL +DEFAULT +1 _edata
+ +6: 2000000000000000 +0 +NOTYPE +GLOBAL +DEFAULT +1 _end
+ +7: 0+ +0 +NOTYPE +GLOBAL +DEFAULT +1 _start\.