Fix mem region parsing regression and add test

In my patch

  Get rid of VEC (mem_region)
  a664f67e50eff30198097d51cec0ec4690abb2a1

I introduced a regression, where the length of the memory region is
assigned to the "hi" field.  It should obviously be computed as "start +
length".  To my defense, no test had caught this :).  As a penance, I
wrote one.

gdb/ChangeLog:

	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
	memory-map-selftests.c.
	(SUBDIR_UNITTESTS_OBS): Add memory-map-selftests.o.
	* memory-map.c (memory_map_start_memory): Fix computation of hi
	address.
	* unittests/memory-map-selftests.c: New file.

4 files changed, 93 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 59324f3..9a22ce7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2017-11-14  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
+	memory-map-selftests.c.
+	(SUBDIR_UNITTESTS_OBS): Add memory-map-selftests.o.
+	* memory-map.c (memory_map_start_memory): Fix computation of hi
+	address.
+	* unittests/memory-map-selftests.c: New file.
+
 2017-11-09  Joel Brobecker  <brobecker@adacore.com>
 
 	* ada-lang.c: Fix some typos in the general command documenting
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 5e01816..a3bfbf9 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -531,6 +531,7 @@ SUBDIR_UNITTESTS_SRCS = \
 	unittests/environ-selftests.c \
 	unittests/function-view-selftests.c \
 	unittests/lookup_name_info-selftests.c \
+	unittests/memory-map-selftests.c \
 	unittests/memrange-selftests.c \
 	unittests/offset-type-selftests.c \
 	unittests/optional-selftests.c \
@@ -544,6 +545,7 @@ SUBDIR_UNITTESTS_OBS = \
 	environ-selftests.o \
 	function-view-selftests.o \
 	lookup_name_info-selftests.o \
+	memory-map-selftests.o \
 	memrange-selftests.o \
 	offset-type-selftests.o \
 	optional-selftests.o \
diff --git a/gdb/memory-map.c b/gdb/memory-map.c
index 9582ceb..e098209 100644
--- a/gdb/memory-map.c
+++ b/gdb/memory-map.c
@@ -71,7 +71,7 @@ memory_map_start_memory (struct gdb_xml_parser *parser,
   type_p
     = (ULONGEST *) xml_find_attribute (attributes, "type")->value;
 
-  data->memory_map->emplace_back (*start_p, *length_p,
+  data->memory_map->emplace_back (*start_p, *start_p + *length_p,
 				  (enum mem_access_mode) *type_p);
 }
 
diff --git a/gdb/unittests/memory-map-selftests.c b/gdb/unittests/memory-map-selftests.c
new file mode 100644
index 0000000..3b282b5
--- /dev/null
+++ b/gdb/unittests/memory-map-selftests.c
@@ -0,0 +1,81 @@
+/* Self tests for memory-map for GDB, the GNU debugger.
+
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#include "defs.h"
+#include "selftest.h"
+#include "memory-map.h"
+
+namespace selftests {
+namespace memory_map_tests {
+
+/* A simple valid test input for parse_memory_map.  */
+
+static const char *valid_mem_map = R"(<?xml version="1.0"?>
+<!DOCTYPE memory-map
+          PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
+                 "http://sourceware.org/gdb/gdb-memory-map.dtd">
+<memory-map>
+  <memory type="ram" start="0" length="4096" />
+  <memory type="rom" start="65536" length="256" />
+  <memory type="flash" start="131072" length="65536">
+    <property name="blocksize">1024</property>
+  </memory>
+</memory-map>
+)";
+
+/* Validate memory region R against some expected values (the other
+   parameters).  */
+
+static void
+check_mem_region (const mem_region &r, CORE_ADDR lo, CORE_ADDR hi,
+		  mem_access_mode mode, int blocksize)
+{
+  SELF_CHECK (r.lo == lo);
+  SELF_CHECK (r.hi == hi);
+  SELF_CHECK (r.enabled_p);
+
+  SELF_CHECK (r.attrib.mode == mode);
+  SELF_CHECK (r.attrib.blocksize == blocksize);
+
+}
+
+/* Test the parse_memory_map function.  */
+
+static void
+parse_memory_map_tests ()
+{
+  std::vector<mem_region> regions = parse_memory_map (valid_mem_map);
+
+  SELF_CHECK (regions.size () == 3);
+
+  check_mem_region (regions[0], 0, 0 + 4096, MEM_RW, -1);
+  check_mem_region (regions[1], 65536, 65536 + 256, MEM_RO, -1);
+  check_mem_region (regions[2], 131072, 131072 + 65536, MEM_FLASH, 1024);
+}
+
+} /* namespace memory_map_tests */
+} /* namespace selftests */
+
+void
+_initialize_memory_map_selftests ()
+{
+  selftests::register_test
+    ("parse_memory_map",
+     selftests::memory_map_tests::parse_memory_map_tests);
+}