RE: [PATCH 02/10] type: add c99 variable length array support

["Agovic, Sanimir" <sanimir.agovic@intel.com>]

> Sanimir> I will add a separate patch which implements DW_AT_count, I
> Sanimir> could not test it as no compiler emits this attribute so far.
> 
> FWIW, it can be tested via the DWARF assembler.
> 
> However it is fine by me if you want to leave it out.
>
Thanks for your review, below you will find a testcase and a fix for a
bug the test revealed. The latter patch will be squashed in v3.

commit 5351ec3e002726893c42c6cf210c8b697a8e51d0
Author: Sanimir Agovic <sanimir.agovic@intel.com>
Date:   Tue Nov 26 14:47:16 2013 +0000

    test: cover subranges with present DW_AT_count attribute
    
    The dwarf attribute DW_AT_count specifies the elements of a subrange.
    This test covers subranges with present count but absent upper bound
    attribute, both with static and dynamic attribute values.
    
    2013-11-26  Sanimir Agovic  <sanimir.agovic@intel.com>
                Keven Boell  <keven.boell@intel.com>
    
    testsuite:
    	* gdb.dwarf2/count.exp: New test.
    
    Change-Id: I58868d4f82691ec3be06b55face759ebc72c930c

diff --git a/gdb/testsuite/gdb.dwarf2/count.exp b/gdb/testsuite/gdb.dwarf2/count.exp
new file mode 100644
index 0000000..a524e89
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/count.exp
@@ -0,0 +1,106 @@
+# Copyright 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Tests to cover DW_AT_count attribute in subranges.
+
+load_lib dwarf.exp
+
+# Only run on targets which support dwarf and gas.
+if { ![dwarf2_support] } {
+    return 0
+}
+
+standard_testfile main.c count.S
+
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+    cu {} {
+ 	compile_unit {{language @DW_LANG_C99}} {
+	    declare_labels char_label array_label static_array_label
+	    declare_labels var_label
+
+	    char_label: base_type {
+		{name char}
+		{encoding @DW_ATE_signed}
+		{byte_size 1 DW_FORM_sdata}
+	    }
+
+	    array_label: array_type {
+	    	{type :$char_label}
+	    } {
+	    	subrange_type {
+	    	    {count {DW_OP_lit5} SPECIAL_expr}
+	    	    {type :$char_label}
+	    	}
+	    }
+
+	    static_array_label: array_type {
+		{type :$char_label}
+	    } {
+		subrange_type {
+		    {count 5 DW_FORM_sdata}
+		    {type :$char_label}
+		}
+	    }
+
+	    DW_TAG_variable {
+	    	{name array}
+	    	{type :$array_label}
+		{const_value hello DW_FORM_block1}
+	    }
+
+	    DW_TAG_variable {
+	    	{name static_array}
+	    	{type :$static_array_label}
+		{const_value world DW_FORM_block1}
+	    }
+	}
+    }
+}
+
+if { [gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \
+	  object {nodebug}] != "" } {
+    return -1
+}
+
+if { [gdb_compile $asm_file ${binfile}2.o object {nodebug}] != "" } {
+    return -1
+}
+
+if { [gdb_compile [list ${binfile}1.o ${binfile}2.o] \
+	  "${binfile}" executable {}] != "" } {
+    return -1
+}
+
+global GDBFLAGS
+set saved_gdbflags $GDBFLAGS
+set GDBFLAGS [concat $GDBFLAGS " -readnow"]
+clean_restart ${testfile}
+set GDBFLAGS $saved_gdbflags
+
+if ![runto_main] {
+    perror "couldn't run to main"
+    return -1
+}
+
+gdb_test "ptype array" "type = char \\\[5]\\\" "ptype array"
+gdb_test "whatis array" "type = char \\\[5]\\\" "whatis array"
+gdb_test "print array" "\"hello\"" "print array"
+gdb_test "print sizeof array" "5" "print sizeof array"
+
+gdb_test "ptype static_array" "type = char \\\[5]\\\" "ptype static_array"
+gdb_test "whatis static_array" "type = char \\\[5]\\\" "whatis static_array"
+gdb_test "print static_array" "\"world\"" "print static_array"
+gdb_test "print sizeof static_array" "5" "print sizeof static_array"




commit 7d44299555837bac03f2230129bc5d88ede6a307
Author: Sanimir Agovic <sanimir.agovic@intel.com>
Date:   Tue Nov 26 14:35:43 2013 +0000

    vla: resolve dynamic bounds if value contents is a constant byte-sequence

    A variable location might be a constant value and therefore no inferior memory
    access is needed to read the content. In this case try to resolve the type
    bounds.

    2013-11-26  Sanimir Agovic  <sanimir.agovic@intel.com>
                Keven Boell  <keven.boell@intel.com>

        * findvar.c (default_read_var_value): Resolve dynamic bounds if location
        points to a constant blob.

    Change-Id: I20ed097565d27e5166a9e8ac275ae41fc6b50e8f

diff --git a/gdb/findvar.c b/gdb/findvar.c
index ec6afd6..c1302d8 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -468,6 +468,9 @@ default_read_var_value (struct symbol *var, struct frame_info *frame)
       return v;

     case LOC_CONST_BYTES:
+      if (is_dynamic_type (type))
+       /* Value is a constant byte-sequence and needs no memory access.  */
+       type = resolve_dynamic_type (type, /* Unused address.  */ 0);
       v = allocate_value (type);
       memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var),
              TYPE_LENGTH (type));
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