base: Add strtoint

ortools/base/BUILD.bazel

@@ -308,6 +308,16 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "strtoint",
+    srcs = ["strtoint.cc"],
+    hdrs = ["strtoint.h"],
+    deps = [
+        ":base",
+        "@com_google_absl//absl/strings",
+    ],
+)
+
 cc_library(
     name = "sysinfo",
     srcs = ["sysinfo.cc"],

ortools/base/strtoint.cc

@@ -0,0 +1,37 @@
+// Copyright 2010-2021 Google LLC
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Architecture-neutral plug compatible replacements for strtol() friends.
+// See strtoint.h for details on how to use this component.
+#include "ortools/base/strtoint.h"
+
+#include <string>
+
+#include "absl/strings/numbers.h"
+#include "ortools/base/logging.h"
+
+namespace operations_research {
+
+int32_t strtoint32(const std::string& word) {
+  int result;
+  CHECK(absl::SimpleAtoi(word, &result));
+  return result;
+}
+
+int64_t strtoint64(const std::string& word) {
+  int64_t result;
+  CHECK(absl::SimpleAtoi(word, &result));
+  return result;
+}
+
+}  // namespace operations_research

ortools/base/strtoint.h

@@ -0,0 +1,61 @@
+// Copyright 2010-2021 Google LLC
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Architecture-neutral plug compatible replacements for strtol() friends.
+//
+// Long's have different lengths on ILP-32 and LP-64 platforms, and so overflow
+// behavior across the two varies when strtol() and similar are used to parse
+// 32-bit integers.  Similar problems exist with atoi(), because although it
+// has an all-integer interface, it uses strtol() internally, and so suffers
+// from the same narrowing problems on assignments to int.
+//
+// Examples:
+//   errno = 0;
+//   i = strtol("3147483647", nullptr, 10);
+//   printf("%d, errno %d\n", i, errno);
+//   //   32-bit platform: 2147483647, errno 34
+//   //   64-bit platform: -1147483649, errno 0
+//
+//   printf("%d\n", atoi("3147483647"));
+//   //   32-bit platform: 2147483647
+//   //   64-bit platform: -1147483649
+//
+// A way round this is to define local replacements for these, and use them
+// instead of the standard libc functions.
+//
+// In most 32-bit cases the replacements can be inlined away to a call to the
+// libc function.  In a couple of 64-bit cases, however, adapters are required,
+// to provide the right overflow and errno behavior.
+//
+
+#ifndef OR_TOOLS_BASE_STRTOINT_H_
+#define OR_TOOLS_BASE_STRTOINT_H_
+
+#include <cstdint>
+#include <string>
+
+#include "absl/base/port.h"  // disable some warnings on Windows
+#include "ortools/base/integral_types.h"
+
+namespace operations_research {
+
+int32_t strtoint32(const std::string& word);
+int64_t strtoint64(const std::string& word);
+
+// Convenience versions of the above that take a string argument.
+inline int32_t atoi32(const std::string& word) { return strtoint32(word); }
+inline int64_t atoi64(const std::string& word) { return strtoint64(word); }
+
+}  // namespace operations_research
+
+#endif  // OR_TOOLS_BASE_STRTOINT_H_