[PATCH] PR gas/21661: Check unsupported .symver with common symbol

["H.J. Lu" <hjl dot tools at gmail dot com>]

The .symver directive on common symbol creates a new common symbol,
which shouldn't be allowed, similar to alias on common symbol:

$ cat y.S
	.comm	bar,8,8
	 .set bar1,bar
$ as -o y.o y.S
y.S: Assembler messages:
y.S:2: Error: `bar1' can't be equated to common symbol 'bar'
$

OK for master?

H.J.
---
	PR gas/21661
	* config/obj-elf.c (obj_elf_symver): Don't allow .symver with
	common symbol.
	(elf_frob_symbol): Likewise.
	* testsuite/gas/elf/elf.exp: Run pr21661.
	* testsuite/gas/elf/pr21661.d: New file.
	* testsuite/gas/elf/pr21661.s: Likewise.
---
 gas/config/obj-elf.c            | 18 ++++++++++++++++++
 gas/testsuite/gas/elf/elf.exp   |  1 +
 gas/testsuite/gas/elf/pr21661.d |  2 ++
 gas/testsuite/gas/elf/pr21661.l |  3 +++
 gas/testsuite/gas/elf/pr21661.s |  4 ++++
 5 files changed, 28 insertions(+)
 create mode 100644 gas/testsuite/gas/elf/pr21661.d
 create mode 100644 gas/testsuite/gas/elf/pr21661.l
 create mode 100644 gas/testsuite/gas/elf/pr21661.s

diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
index 3696d5e..94ffb31 100644
--- a/gas/config/obj-elf.c
+++ b/gas/config/obj-elf.c
@@ -1414,6 +1414,14 @@ obj_elf_symver (int ignore ATTRIBUTE_UNUSED)
   c = get_symbol_name (& name);
   lex_type[(unsigned char) '@'] = old_lexat;
 
+  if (S_IS_COMMON (sym))
+    {
+      as_bad (_("`%s' can't be versioned to common symbol '%s'"),
+	      name, S_GET_NAME (sym));
+      ignore_rest_of_line ();
+      return;
+    }
+
   if (symbol_get_obj (sym)->versioned_name == NULL)
     {
       symbol_get_obj (sym)->versioned_name = xstrdup (name);
@@ -2301,6 +2309,16 @@ elf_frob_symbol (symbolS *symp, int *puntp)
 	    }
 	}
     }
+  else if (S_IS_COMMON (symp))
+    {
+      const char *sname = S_GET_NAME (symp);
+      if (strchr (sname, ELF_VER_CHR))
+	{
+	  as_bad (_("symbol `%s' can't be versioned to common symbol"),
+		  sname);
+	  return;
+	}
+    }
 
   /* Double check weak symbols.  */
   if (S_IS_WEAK (symp))
diff --git a/gas/testsuite/gas/elf/elf.exp b/gas/testsuite/gas/elf/elf.exp
index ad38d66..6b2b31a 100644
--- a/gas/testsuite/gas/elf/elf.exp
+++ b/gas/testsuite/gas/elf/elf.exp
@@ -184,6 +184,7 @@ if { [is_elf_format] } then {
 	run_dump_test "symtab"
     }
     run_dump_test "symver"
+    run_dump_test "pr21661"
 
     # No indirect functions on non-GNU targets.
     # The Visium and MSP set the ELF header's OSABI field to ELFOSABI_STANDALONE.
diff --git a/gas/testsuite/gas/elf/pr21661.d b/gas/testsuite/gas/elf/pr21661.d
new file mode 100644
index 0000000..a16e410
--- /dev/null
+++ b/gas/testsuite/gas/elf/pr21661.d
@@ -0,0 +1,2 @@
+#name: unsupported .symver with common symbol
+#error-output: pr21661.l
diff --git a/gas/testsuite/gas/elf/pr21661.l b/gas/testsuite/gas/elf/pr21661.l
new file mode 100644
index 0000000..daf0d36
--- /dev/null
+++ b/gas/testsuite/gas/elf/pr21661.l
@@ -0,0 +1,3 @@
+[^:]*: Assembler messages:
+[^:]*:2: Error: `foo@VERS.1' can't be versioned to common symbol 'foo'
+[^:]*: Error: symbol `bar@VERS.1' can't be versioned to common symbol
diff --git a/gas/testsuite/gas/elf/pr21661.s b/gas/testsuite/gas/elf/pr21661.s
new file mode 100644
index 0000000..5586bfd
--- /dev/null
+++ b/gas/testsuite/gas/elf/pr21661.s
@@ -0,0 +1,4 @@
+	.comm	foo,8,8
+	 .symver foo,foo@VERS.1
+	 .symver bar,bar@VERS.1
+	.comm	bar,8,8
-- 
2.9.4