Index: lldb/source/Host/common/XML.cpp
===================================================================
--- lldb/source/Host/common/XML.cpp
+++ lldb/source/Host/common/XML.cpp
@@ -153,14 +153,11 @@
 
 bool XMLNode::GetAttributeValueAsUnsigned(const char *name, uint64_t &value,
                                           uint64_t fail_value, int base) const {
-#if LLDB_ENABLE_LIBXML2
-  llvm::StringRef str_value = GetAttributeValue(name, "");
-#else
-  llvm::StringRef str_value;
-#endif
-  bool success = false;
-  value = StringConvert::ToUInt64(str_value.data(), fail_value, base, &success);
-  return success;
+  if (llvm::to_integer(GetAttributeValue(name, ""), value, base))
+    return true;
+
+  value = fail_value;
+  return false;
 }
 
 void XMLNode::ForEachChildNode(NodeCallback const &callback) const {
@@ -302,33 +299,21 @@
 
 bool XMLNode::GetElementTextAsUnsigned(uint64_t &value, uint64_t fail_value,
                                        int base) const {
-  bool success = false;
-#if LLDB_ENABLE_LIBXML2
-  if (IsValid()) {
-    std::string text;
-    if (GetElementText(text))
-      value = StringConvert::ToUInt64(text.c_str(), fail_value, base, &success);
-  }
-#endif
-  if (!success)
-    value = fail_value;
-  return success;
+  std::string text;
+  if (GetElementText(text) && llvm::to_integer(text,value, base))
+    return true;
+
+  value = fail_value;
+  return false;
 }
 
 bool XMLNode::GetElementTextAsFloat(double &value, double fail_value) const {
-  bool success = false;
-#if LLDB_ENABLE_LIBXML2
-  if (IsValid()) {
-    std::string text;
-    if (GetElementText(text)) {
-      value = atof(text.c_str());
-      success = true;
-    }
-  }
-#endif
-  if (!success)
-    value = fail_value;
-  return success;
+  std::string text;
+  if (GetElementText(text) && llvm::to_float(text, value))
+    return true;
+
+  value = fail_value;
+  return false;
 }
 
 bool XMLNode::NameIs(const char *name) const {
Index: lldb/unittests/Host/CMakeLists.txt
===================================================================
--- lldb/unittests/Host/CMakeLists.txt
+++ lldb/unittests/Host/CMakeLists.txt
@@ -12,6 +12,7 @@
   SocketAddressTest.cpp
   SocketTest.cpp
   SocketTestUtilities.cpp
+  XMLTest.cpp
 )
 
 if (CMAKE_SYSTEM_NAME MATCHES "Linux|Android")
Index: lldb/unittests/Host/XMLTest.cpp
===================================================================
--- /dev/null
+++ lldb/unittests/Host/XMLTest.cpp
@@ -0,0 +1,119 @@
+//===-- XMLTest.cpp -------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/XML.h"
+#include "gtest/gtest.h"
+
+using namespace lldb_private;
+
+#if LLDB_ENABLE_LIBXML2
+
+static void assertGetElement(XMLNode &root, const char *element_name,
+                             bool expected_uint_success, uint64_t expected_uint,
+                             bool expected_double_success,
+                             double expected_double) {
+  XMLNode node = root.FindFirstChildElementWithName(element_name);
+  ASSERT_TRUE(node.IsValid());
+
+  uint64_t uint_val;
+  EXPECT_EQ(node.GetElementTextAsUnsigned(uint_val, 66, 0),
+            expected_uint_success);
+  EXPECT_EQ(uint_val, expected_uint);
+
+  double double_val;
+  EXPECT_EQ(node.GetElementTextAsFloat(double_val, 66.0),
+            expected_double_success);
+  EXPECT_EQ(double_val, expected_double);
+
+  XMLNode attr_node = root.FindFirstChildElementWithName("attr");
+  ASSERT_TRUE(node.IsValid());
+
+  EXPECT_EQ(
+      attr_node.GetAttributeValueAsUnsigned(element_name, uint_val, 66, 0),
+      expected_uint_success);
+  EXPECT_EQ(uint_val, expected_uint);
+}
+
+#define ASSERT_GET(element_name, ...)                                          \
+  {                                                                            \
+    SCOPED_TRACE("at element/attribute " element_name);                        \
+    assertGetElement(root, element_name, __VA_ARGS__);                         \
+  }
+
+TEST(XML, GetAs) {
+  std::string test_xml =
+      "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
+      "<test>\n"
+      "  <empty/>\n"
+      "  <text>123foo</text>\n"
+      "  <positive-int>11</positive-int>\n"
+      "  <negative-int>-11</negative-int>\n"
+      "  <positive-overflow>18446744073709551616</positive-overflow>\n"
+      "  <negative-overflow>-9223372036854775809</negative-overflow>\n"
+      "  <hex>0x1234</hex>\n"
+      "  <positive-float>12.5</positive-float>\n"
+      "  <negative-float>-12.5</negative-float>\n"
+      "  <attr empty=\"\"\n"
+      "        text=\"123foo\"\n"
+      "        positive-int=\"11\"\n"
+      "        negative-int=\"-11\"\n"
+      "        positive-overflow=\"18446744073709551616\"\n"
+      "        negative-overflow=\"-9223372036854775809\"\n"
+      "        hex=\"0x1234\"\n"
+      "        positive-float=\"12.5\"\n"
+      "        negative-float=\"-12.5\"\n"
+      "       />\n"
+      "</test>\n";
+
+  XMLDocument doc;
+  ASSERT_TRUE(doc.ParseMemory(test_xml.data(), test_xml.size()));
+
+  XMLNode root = doc.GetRootElement();
+  ASSERT_TRUE(root.IsValid());
+
+  ASSERT_GET("empty", false, 66, false, 66.0);
+  ASSERT_GET("text", false, 66, false, 66.0);
+  ASSERT_GET("positive-int", true, 11, true, 11.0);
+  ASSERT_GET("negative-int", false, 66, true, -11.0);
+  ASSERT_GET("positive-overflow", false, 66, true, 18446744073709551616.0);
+  ASSERT_GET("negative-overflow", false, 66, true, -9223372036854775809.0);
+  ASSERT_GET("hex", true, 0x1234, true, 4660.0);
+  ASSERT_GET("positive-float", false, 66, true, 12.5);
+  ASSERT_GET("negative-float", false, 66, true, -12.5);
+}
+
+#else // !LLDB_ENABLE_LIBXML2
+
+TEST(XML, GracefulNoXML) {
+  std::string test_xml =
+      "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
+      "<test>\n"
+      "  <text attribute=\"123\">123</text>\n"
+      "</test>\n";
+
+  XMLDocument doc;
+  ASSERT_FALSE(doc.ParseMemory(test_xml.data(), test_xml.size()));
+
+  XMLNode root = doc.GetRootElement();
+  EXPECT_FALSE(root.IsValid());
+
+  XMLNode node = root.FindFirstChildElementWithName("text");
+  EXPECT_FALSE(node.IsValid());
+
+  uint64_t uint_val;
+  EXPECT_FALSE(node.GetElementTextAsUnsigned(uint_val, 66, 0));
+  EXPECT_EQ(uint_val, 66U);
+  EXPECT_FALSE(node.GetAttributeValueAsUnsigned("attribute", uint_val, 66, 0));
+  EXPECT_EQ(uint_val, 66U);
+
+  double double_val;
+  EXPECT_FALSE(node.GetElementTextAsFloat(double_val, 66.0));
+  EXPECT_EQ(double_val, 66.0);
+}
+
+#endif // LLDB_ENABLE_LIBXML2