gas: consistently emit diagnostics for non-zero data emission to .bss/.struct

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 69e1061..4dcb9cd 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,18 @@
 2015-12-08  Jan Beulich  <jbeulich@suse.com>
 
+       * read.c (in_bss): New.
+       (do_align): Use it to also warn for non-zero fill in .bss.
+       (do_org): Likewise.
+       (s_space): Likewise.
+       (s_fill): Error on bad use in .bss/.struct.
+       (float_cons): Likewise.
+       (emit_leb128_expr): Likewise.
+       (emit_expr_with_reloc): Defer handling use inside .struct. Also
+       error on non-zero item added to .bss.
+       (stringer_append_char): Error on non-zero character.
+
+2015-12-08  Jan Beulich  <jbeulich@suse.com>
+
        * read.c (stringer): Move absolute section check up. Return
        right away.
 

diff --git a/gas/read.c b/gas/read.c
index 172d75f..b25ab8d 100644 (file)
--- a/gas/read.c
+++ b/gas/read.c
@@ -1337,6 +1337,14 @@ convert_to_bignum (expressionS *exp, int sign)
   exp->X_add_number = i;
 }
 
+static bfd_boolean
+in_bss (void)
+{
+  flagword flags = bfd_get_section_flags (stdoutput, now_seg);
+
+  return (flags & SEC_ALLOC) && !(flags & (SEC_LOAD | SEC_HAS_CONTENTS));
+}
+
 /* For most MRI pseudo-ops, the line actually ends at the first
    nonquoted space.  This function looks for that point, stuffs a null
    in, and sets *STOPCP to the character that used to be there, and
@@ -1402,13 +1410,17 @@ s_abort (int ignore ATTRIBUTE_UNUSED)
 static void
 do_align (int n, char *fill, int len, int max)
 {
-  if (now_seg == absolute_section)
+  if (now_seg == absolute_section || in_bss ())
     {
       if (fill != NULL)
        while (len-- > 0)
          if (*fill++ != '\0')
            {
-             as_warn (_("ignoring fill value in absolute section"));
+             if (now_seg == absolute_section)
+               as_warn (_("ignoring fill value in absolute section"));
+             else
+               as_warn (_("ignoring fill value in section `%s'"),
+                        segment_name (now_seg));
              break;
            }
       fill = NULL;
@@ -2207,6 +2219,20 @@ s_fill (int ignore ATTRIBUTE_UNUSED)
 
   if (size && !need_pass_2)
     {
+      if (now_seg == absolute_section)
+       {
+         if (rep_exp.X_op != O_constant)
+           as_bad (_("non-constant fill count for absolute section"));
+         else if (fill && rep_exp.X_add_number != 0)
+           as_bad (_("attempt to fill absolute section with non-zero value"));
+         abs_section_offset += rep_exp.X_add_number * size;
+       }
+      else if (fill
+              && (rep_exp.X_op != O_constant || rep_exp.X_add_number != 0)
+              && in_bss ())
+       as_bad (_("attempt to fill section `%s' with non-zero value"),
+               segment_name (now_seg));
+
       if (rep_exp.X_op == O_constant)
        {
          p = frag_var (rs_fill, (int) size, (int) size,
@@ -2777,6 +2803,10 @@ do_org (segT segment, expressionS *exp, int fill)
       symbolS *sym = exp->X_add_symbol;
       offsetT off = exp->X_add_number * OCTETS_PER_BYTE;
 
+      if (fill && in_bss ())
+       as_warn (_("ignoring fill value in section `%s'"),
+                segment_name (now_seg));
+
       if (exp->X_op != O_constant && exp->X_op != O_symbol)
        {
          /* Handle complex expressions.  */
@@ -3331,10 +3361,11 @@ s_space (int mult)
       val.X_add_number = 0;
     }
 
-  if (val.X_op != O_constant
-      || val.X_add_number < - 0x80
-      || val.X_add_number > 0xff
-      || (mult != 0 && mult != 1 && val.X_add_number != 0))
+  if ((val.X_op != O_constant
+       || val.X_add_number < - 0x80
+       || val.X_add_number > 0xff
+       || (mult != 0 && mult != 1 && val.X_add_number != 0))
+      && (now_seg != absolute_section && !in_bss ()))
     {
       resolve_expression (&exp);
       if (exp.X_op != O_constant)
@@ -3375,6 +3406,8 @@ s_space (int mult)
          /* If we are in the absolute section, just bump the offset.  */
          if (now_seg == absolute_section)
            {
+             if (val.X_op != O_constant || val.X_add_number != 0)
+               as_warn (_("ignoring fill value in absolute section"));
              abs_section_offset += repeat;
              goto getout;
            }
@@ -3412,7 +3445,10 @@ s_space (int mult)
                          make_expr_symbol (&exp), (offsetT) 0, (char *) 0);
        }
 
-      if (p)
+      if ((val.X_op != O_constant || val.X_add_number != 0) && in_bss ())
+       as_warn (_("ignoring fill value in section `%s'"),
+                segment_name (now_seg));
+      else if (p)
        *p = val.X_add_number;
     }
 
@@ -4213,15 +4249,6 @@ emit_expr_with_reloc (expressionS *exp,
 
   op = exp->X_op;
 
-  /* Allow `.word 0' in the absolute section.  */
-  if (now_seg == absolute_section)
-    {
-      if (op != O_constant || exp->X_add_number != 0)
-       as_bad (_("attempt to store value in absolute section"));
-      abs_section_offset += nbytes;
-      return;
-    }
-
   /* Handle a negative bignum.  */
   if (op == O_uminus
       && exp->X_add_number == 0
@@ -4271,6 +4298,20 @@ emit_expr_with_reloc (expressionS *exp,
       op = O_constant;
     }
 
+  /* Allow `.word 0' in the absolute section.  */
+  if (now_seg == absolute_section)
+    {
+      if (op != O_constant || exp->X_add_number != 0)
+       as_bad (_("attempt to store value in absolute section"));
+      abs_section_offset += nbytes;
+      return;
+    }
+
+  /* Allow `.word 0' in BSS style sections.  */
+  if ((op != O_constant || exp->X_add_number != 0) && in_bss ())
+    as_bad (_("attempt to store non-zero value in section `%s'"),
+           segment_name (now_seg));
+
   p = frag_more ((int) nbytes);
 
   if (reloc != TC_PARSE_CONS_RETURN_NONE)
@@ -4854,6 +4895,21 @@ float_cons (/* Clobbers input_line-pointer, checks end-of-line.  */
       return;
     }
 
+  if (now_seg == absolute_section)
+    {
+      as_bad (_("attempt to store float in absolute section"));
+      ignore_rest_of_line ();
+      return;
+    }
+
+  if (in_bss ())
+    {
+      as_bad (_("attempt to store float in section `%s'"),
+             segment_name (now_seg));
+      ignore_rest_of_line ();
+      return;
+    }
+
 #ifdef md_flush_pending_output
   md_flush_pending_output ();
 #endif
@@ -5186,6 +5242,18 @@ emit_leb128_expr (expressionS *exp, int sign)
       op = O_big;
     }
 
+  if (now_seg == absolute_section)
+    {
+      if (op != O_constant || exp->X_add_number != 0)
+       as_bad (_("attempt to store value in absolute section"));
+      abs_section_offset++;
+      return;
+    }
+
+  if ((op != O_constant || exp->X_add_number != 0) && in_bss ())
+    as_bad (_("attempt to store non-zero value in section `%s'"),
+           segment_name (now_seg));
+
   /* Let check_eh_frame know that data is being emitted.  nbytes == -1 is
      a signal that this is leb128 data.  It shouldn't optimize this away.  */
   nbytes = (unsigned int) -1;
@@ -5255,6 +5323,10 @@ s_leb128 (int sign)
 static void
 stringer_append_char (int c, int bitsize)
 {
+  if (c && in_bss ())
+    as_bad (_("attempt to store non-empty string in section `%s'"),
+           segment_name (now_seg));
+
   if (!target_big_endian)
     FRAG_APPEND_1_CHAR (c);
 

diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index bc524e9..a90b0fb 100644 (file)
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,5 +1,11 @@
 2015-12-08  Jan Beulich  <jbeulich@suse.com>
 
+       * gas/elf/bad-bss.d, gas/elf/bad-bss.err: New.
+       * gas/elf/bss.d, gas/elf/bss.s: New.
+       * gas/elf/elf.exp: Run new tests.
+
+2015-12-08  Jan Beulich  <jbeulich@suse.com>
+
        * gas/elf/file-2.s, gas/elf/file-2.d: New.
        * gas/elf/elf.exp: Run new test.
        * gas/elf/file.d: Adjust expectations.

diff --git a/gas/testsuite/gas/elf/bad-bss.d b/gas/testsuite/gas/elf/bad-bss.d
new file mode 100644 (file)
index 0000000..98721cf
--- /dev/null
+++ b/gas/testsuite/gas/elf/bad-bss.d
@@ -0,0 +1,4 @@
+#name: bad .bss / .struct data allocation directives
+#source: bss.s
+#error-output: bad-bss.err
+#target: i?86-*-* x86_64-*-* ia64-*-* arm-*-* aarch64-*-*

diff --git a/gas/testsuite/gas/elf/bad-bss.err b/gas/testsuite/gas/elf/bad-bss.err
new file mode 100644 (file)
index 0000000..a2eccba
--- /dev/null
+++ b/gas/testsuite/gas/elf/bad-bss.err
@@ -0,0 +1,63 @@
+.*bss\.s: Assembler messages:
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store float in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-empty string in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-empty string in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to fill section .\.bss. with non-zero value
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss.
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store float in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-empty string in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-empty string in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to fill section .\.bss\.local. with non-zero value
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.bss\.local.
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store float in section .\.private.
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-empty string in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-empty string in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to fill section .\.private. with non-zero value
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Error: attempt to store non-zero value in section .\.private.
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Warning: zero assumed.*
+.*bss\.s:[1-9][0-9]*: Error: attempt to store value in absolute section
+.*bss\.s:[1-9][0-9]*: Error: attempt to store value in absolute section
+.*bss\.s:[1-9][0-9]*: Error: attempt to store value in absolute section
+.*bss\.s:[1-9][0-9]*: Error: attempt to store float in absolute section
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in absolute section
+.*bss\.s:[1-9][0-9]*: Error: attempt to fill absolute section with non-zero value
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in absolute section
+.*bss\.s:[1-9][0-9]*: Warning: ignoring fill value in absolute section
+.*bss\.s:[1-9][0-9]*: Error: attempt to store value in absolute section
+.*bss\.s:[1-9][0-9]*: Error: attempt to store value in absolute section

diff --git a/gas/testsuite/gas/elf/bss.d b/gas/testsuite/gas/elf/bss.d
new file mode 100644 (file)
index 0000000..711e74a
--- /dev/null
+++ b/gas/testsuite/gas/elf/bss.d
@@ -0,0 +1,24 @@
+#name: good .bss / .struct data allocation directives
+#as: --defsym okay=1
+#warning: Warning: zero assumed
+#readelf: -sSW
+#target: i?86-*-* x86_64-*-* ia64-*-* arm-*-* aarch64-*-*
+
+There are [1-9][0-9]* section headers, starting at offset 0x[0-9a-f]*:
+
+Section Headers:
+#...
+ *\[ [1-9]\] *\.bss        +NOBITS +0*0 +0[0-9a-f]* 0*(28|40) +0*0 +WA +0 +0 +32
+ *\[ [1-9]\] *\.bss\.local +NOBITS +0*0 +0[0-9a-f]* 0*(28|40) +0*0 +WA +0 +0 +32
+ *\[ [1-9]\] *\.private    +NOBITS +0*0 +0[0-9a-f]* 0*(28|40) +0*0 +WA +0 +0 +32
+#...
+Symbol table '\.symtab' contains [1-9][0-9]* entries:
+#...
+ *[0-9]*: 0*28 *0 NOTYPE *LOCAL *DEFAULT *[1-9] endof_bss
+#...
+ *[0-9]*: 0*28 *0 NOTYPE *LOCAL *DEFAULT *[1-9] endof_bss_local
+#...
+ *[0-9]*: 0*28 *0 NOTYPE *LOCAL *DEFAULT *[1-9] endof_private
+#...
+ *[0-9]*: 0*27 *0 NOTYPE *LOCAL *DEFAULT *ABS endof_struct
+#pass

diff --git a/gas/testsuite/gas/elf/bss.s b/gas/testsuite/gas/elf/bss.s
new file mode 100644 (file)
index 0000000..1a666ae
--- /dev/null
+++ b/gas/testsuite/gas/elf/bss.s
@@ -0,0 +1,56 @@
+       .macro  bss name
+
+       .long   0
+       .long   ,
+
+       .balign 32
+
+       .ifnes "\name", "struct"
+       .ascii  ""
+       .asciz  ""
+       .endif
+
+       .fill   1, 1
+       .org    .+1
+       .skip   1
+       .sleb128
+       .sleb128 0
+       .uleb128
+       .uleb128 0
+
+       .ifndef okay
+
+       .long   1
+       .long   .
+       .long   x
+       .float  0.0
+
+       .balign 32, -1
+
+       .ifnes "\name", "struct"
+       .ascii  "0"
+       .asciz  "0"
+       .endif
+
+       .fill   1, 1, -1
+       .org    .+1, -1
+       .skip   1, -1
+       .sleb128 -1
+       .uleb128 1
+
+       .endif
+
+endof_\name:
+       .endm
+
+       .bss
+       bss     bss
+
+       .section .bss.local, "aw"
+       bss     bss_local
+
+       .section .private, "aw", %nobits
+       bss     private
+
+       .struct
+       bss     struct

diff --git a/gas/testsuite/gas/elf/elf.exp b/gas/testsuite/gas/elf/elf.exp
index 99292d7..f9fc5d4 100644 (file)
--- a/gas/testsuite/gas/elf/elf.exp
+++ b/gas/testsuite/gas/elf/elf.exp
@@ -205,6 +205,8 @@ if { [is_elf_format] } then {
     run_dump_test "dwarf2-2"
     run_dump_test "dwarf2-3"
     run_dump_test "dwarf2-4"
+    run_dump_test "bss"
+    run_dump_test "bad-bss"
     run_dump_test "bad-section-flag"
     run_dump_test "bad-size"
     run_dump_test "bad-group"