Merge topic 'json-helpers'

b2f3f831e2 Refactor: Use JSON helpers in CTest resource spec
3f3a30e1e0 JSON: Add helpers

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !5197

4 files changed, 437 insertions, 91 deletions

diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 310ffeb..1be424a 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -336,6 +336,7 @@ set(SRCS
   cmInstallTargetGenerator.cxx
   cmInstallDirectoryGenerator.h
   cmInstallDirectoryGenerator.cxx
+  cmJSONHelpers.h
   cmLDConfigLDConfigTool.cxx
   cmLDConfigLDConfigTool.h
   cmLDConfigTool.cxx
diff --git a/Source/CTest/cmCTestResourceSpec.cxx b/Source/CTest/cmCTestResourceSpec.cxx
index 21c97de..101dc2c 100644
--- a/Source/CTest/cmCTestResourceSpec.cxx
+++ b/Source/CTest/cmCTestResourceSpec.cxx
@@ -2,19 +2,140 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "cmCTestResourceSpec.h"
 
+#include <functional>
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
 
+#include <cmext/string_view>
+
 #include <cm3p/json/reader.h>
 #include <cm3p/json/value.h>
 
 #include "cmsys/FStream.hxx"
 #include "cmsys/RegularExpression.hxx"
 
-static const cmsys::RegularExpression IdentifierRegex{ "^[a-z_][a-z0-9_]*$" };
-static const cmsys::RegularExpression IdRegex{ "^[a-z0-9_]+$" };
+#include "cmJSONHelpers.h"
+
+namespace {
+const cmsys::RegularExpression IdentifierRegex{ "^[a-z_][a-z0-9_]*$" };
+const cmsys::RegularExpression IdRegex{ "^[a-z0-9_]+$" };
+
+struct Version
+{
+  int Major = 1;
+  int Minor = 0;
+};
+
+struct TopVersion
+{
+  struct Version Version;
+};
+
+auto const VersionFieldHelper =
+  cmJSONIntHelper<cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_VERSION);
+
+auto const VersionHelper =
+  cmJSONRequiredHelper<Version, cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::NO_VERSION,
+    cmJSONObjectHelper<Version, cmCTestResourceSpec::ReadFileResult>(
+      cmCTestResourceSpec::ReadFileResult::READ_OK,
+      cmCTestResourceSpec::ReadFileResult::INVALID_VERSION)
+      .Bind("major"_s, &Version::Major, VersionFieldHelper)
+      .Bind("minor"_s, &Version::Minor, VersionFieldHelper));
+
+auto const RootVersionHelper =
+  cmJSONObjectHelper<TopVersion, cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_ROOT)
+    .Bind("version"_s, &TopVersion::Version, VersionHelper, false);
+
+cmCTestResourceSpec::ReadFileResult ResourceIdHelper(std::string& out,
+                                                     const Json::Value* value)
+{
+  auto result = cmJSONStringHelper(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_RESOURCE)(out, value);
+  if (result != cmCTestResourceSpec::ReadFileResult::READ_OK) {
+    return result;
+  }
+  cmsys::RegularExpressionMatch match;
+  if (!IdRegex.find(out.c_str(), match)) {
+    return cmCTestResourceSpec::ReadFileResult::INVALID_RESOURCE;
+  }
+  return cmCTestResourceSpec::ReadFileResult::READ_OK;
+}
+
+auto const ResourceHelper =
+  cmJSONObjectHelper<cmCTestResourceSpec::Resource,
+                     cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_RESOURCE)
+    .Bind("id"_s, &cmCTestResourceSpec::Resource::Id, ResourceIdHelper)
+    .Bind("slots"_s, &cmCTestResourceSpec::Resource::Capacity,
+          cmJSONUIntHelper(
+            cmCTestResourceSpec::ReadFileResult::READ_OK,
+            cmCTestResourceSpec::ReadFileResult::INVALID_RESOURCE, 1),
+          false);
+
+auto const ResourceListHelper =
+  cmJSONVectorHelper<cmCTestResourceSpec::Resource,
+                     cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_RESOURCE_TYPE,
+    ResourceHelper);
+
+auto const ResourceMapHelper =
+  cmJSONMapFilterHelper<std::vector<cmCTestResourceSpec::Resource>,
+                        cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_SOCKET_SPEC,
+    ResourceListHelper, [](const std::string& key) -> bool {
+      cmsys::RegularExpressionMatch match;
+      return IdentifierRegex.find(key.c_str(), match);
+    });
+
+auto const SocketSetHelper = cmJSONVectorHelper<
+  std::map<std::string, std::vector<cmCTestResourceSpec::Resource>>>(
+  cmCTestResourceSpec::ReadFileResult::READ_OK,
+  cmCTestResourceSpec::ReadFileResult::INVALID_SOCKET_SPEC, ResourceMapHelper);
+
+cmCTestResourceSpec::ReadFileResult SocketHelper(
+  cmCTestResourceSpec::Socket& out, const Json::Value* value)
+{
+  std::vector<
+    std::map<std::string, std::vector<cmCTestResourceSpec::Resource>>>
+    sockets;
+  cmCTestResourceSpec::ReadFileResult result = SocketSetHelper(sockets, value);
+  if (result != cmCTestResourceSpec::ReadFileResult::READ_OK) {
+    return result;
+  }
+  if (sockets.size() > 1) {
+    return cmCTestResourceSpec::ReadFileResult::INVALID_SOCKET_SPEC;
+  }
+  if (sockets.empty()) {
+    out.Resources.clear();
+  } else {
+    out.Resources = std::move(sockets[0]);
+  }
+  return cmCTestResourceSpec::ReadFileResult::READ_OK;
+}
+
+auto const LocalRequiredHelper =
+  cmJSONRequiredHelper<cmCTestResourceSpec::Socket,
+                       cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::INVALID_SOCKET_SPEC, SocketHelper);
+
+auto const RootHelper =
+  cmJSONObjectHelper<cmCTestResourceSpec, cmCTestResourceSpec::ReadFileResult>(
+    cmCTestResourceSpec::ReadFileResult::READ_OK,
+    cmCTestResourceSpec::ReadFileResult::INVALID_ROOT)
+    .Bind("local", &cmCTestResourceSpec::LocalSocket, LocalRequiredHelper,
+          false);
+}
 
 cmCTestResourceSpec::ReadFileResult cmCTestResourceSpec::ReadFromJSONFile(
   const std::string& filename)
@@ -30,99 +151,17 @@ cmCTestResourceSpec::ReadFileResult cmCTestResourceSpec::ReadFromJSONFile(
     return ReadFileResult::JSON_PARSE_ERROR;
   }
 
-  if (!root.isObject()) {
-    return ReadFileResult::INVALID_ROOT;
-  }
-
-  int majorVersion = 1;
-  int minorVersion = 0;
-  if (root.isMember("version")) {
-    auto const& version = root["version"];
-    if (version.isObject()) {
-      if (!version.isMember("major") || !version.isMember("minor")) {
-        return ReadFileResult::INVALID_VERSION;
-      }
-      auto const& major = version["major"];
-      auto const& minor = version["minor"];
-      if (!major.isInt() || !minor.isInt()) {
-        return ReadFileResult::INVALID_VERSION;
-      }
-      majorVersion = major.asInt();
-      minorVersion = minor.asInt();
-    } else {
-      return ReadFileResult::INVALID_VERSION;
-    }
-  } else {
-    return ReadFileResult::NO_VERSION;
+  TopVersion version;
+  ReadFileResult result;
+  if ((result = RootVersionHelper(version, &root)) !=
+      ReadFileResult::READ_OK) {
+    return result;
   }
-
-  if (majorVersion != 1 || minorVersion != 0) {
+  if (version.Version.Major != 1 || version.Version.Minor != 0) {
     return ReadFileResult::UNSUPPORTED_VERSION;
   }
 
-  auto const& local = root["local"];
-  if (!local.isArray()) {
-    return ReadFileResult::INVALID_SOCKET_SPEC;
-  }
-  if (local.size() > 1) {
-    return ReadFileResult::INVALID_SOCKET_SPEC;
-  }
-
-  if (local.empty()) {
-    this->LocalSocket.Resources.clear();
-    return ReadFileResult::READ_OK;
-  }
-
-  auto const& localSocket = local[0];
-  if (!localSocket.isObject()) {
-    return ReadFileResult::INVALID_SOCKET_SPEC;
-  }
-  std::map<std::string, std::vector<cmCTestResourceSpec::Resource>> resources;
-  cmsys::RegularExpressionMatch match;
-  for (auto const& key : localSocket.getMemberNames()) {
-    if (IdentifierRegex.find(key.c_str(), match)) {
-      auto const& value = localSocket[key];
-      auto& r = resources[key];
-      if (value.isArray()) {
-        for (auto const& item : value) {
-          if (item.isObject()) {
-            cmCTestResourceSpec::Resource resource;
-
-            if (!item.isMember("id")) {
-              return ReadFileResult::INVALID_RESOURCE;
-            }
-            auto const& id = item["id"];
-            if (!id.isString()) {
-              return ReadFileResult::INVALID_RESOURCE;
-            }
-            resource.Id = id.asString();
-            if (!IdRegex.find(resource.Id.c_str(), match)) {
-              return ReadFileResult::INVALID_RESOURCE;
-            }
-
-            if (item.isMember("slots")) {
-              auto const& capacity = item["slots"];
-              if (!capacity.isConvertibleTo(Json::uintValue)) {
-                return ReadFileResult::INVALID_RESOURCE;
-              }
-              resource.Capacity = capacity.asUInt();
-            } else {
-              resource.Capacity = 1;
-            }
-
-            r.push_back(resource);
-          } else {
-            return ReadFileResult::INVALID_RESOURCE;
-          }
-        }
-      } else {
-        return ReadFileResult::INVALID_RESOURCE_TYPE;
-      }
-    }
-  }
-
-  this->LocalSocket.Resources = std::move(resources);
-  return ReadFileResult::READ_OK;
+  return RootHelper(*this, &root);
 }
 
 const char* cmCTestResourceSpec::ResultToString(ReadFileResult result)
diff --git a/Source/CTest/cmCTestResourceSpec.h b/Source/CTest/cmCTestResourceSpec.h
index 1aa279b..72628a3 100644
--- a/Source/CTest/cmCTestResourceSpec.h
+++ b/Source/CTest/cmCTestResourceSpec.h
@@ -2,6 +2,8 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #pragma once
 
+#include "cmConfigure.h" // IWYU pragma: keep
+
 #include <map>
 #include <string>
 #include <vector>
diff --git a/Source/cmJSONHelpers.h b/Source/cmJSONHelpers.h
new file mode 100644
index 0000000..2da2a03
--- /dev/null
+++ b/Source/cmJSONHelpers.h
@@ -0,0 +1,304 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#pragma once
+
+#include <algorithm>
+#include <cstddef>
+#include <functional>
+#include <map>
+#include <string>
+#include <vector>
+
+#include <cm/optional>
+#include <cm/string_view>
+
+#include <cm3p/json/value.h>
+
+template <typename T, typename E>
+using cmJSONHelper = std::function<E(T& out, const Json::Value* value)>;
+
+template <typename T, typename E>
+class cmJSONObjectHelper
+{
+public:
+  cmJSONObjectHelper(E&& success, E&& fail, bool allowExtra = true);
+
+  template <typename U, typename M, typename F>
+  cmJSONObjectHelper& Bind(const cm::string_view& name, M U::*member, F func,
+                           bool required = true);
+  template <typename M, typename F>
+  cmJSONObjectHelper& Bind(const cm::string_view& name, std::nullptr_t, F func,
+                           bool required = true);
+
+  E operator()(T& out, const Json::Value* value) const;
+
+private:
+  // Not a true cmJSONHelper, it just happens to match the signature
+  using MemberFunction = std::function<E(T& out, const Json::Value* value)>;
+  struct Member
+  {
+    cm::string_view Name;
+    MemberFunction Function;
+    bool Required;
+  };
+  std::vector<Member> Members;
+  bool AnyRequired = false;
+  E Success;
+  E Fail;
+  bool AllowExtra;
+
+  cmJSONObjectHelper& BindPrivate(const cm::string_view& name,
+                                  MemberFunction&& func, bool required);
+};
+
+template <typename T, typename E>
+cmJSONObjectHelper<T, E>::cmJSONObjectHelper(E&& success, E&& fail,
+                                             bool allowExtra)
+  : Success(std::move(success))
+  , Fail(std::move(fail))
+  , AllowExtra(allowExtra)
+{
+}
+
+template <typename T, typename E>
+template <typename U, typename M, typename F>
+cmJSONObjectHelper<T, E>& cmJSONObjectHelper<T, E>::Bind(
+  const cm::string_view& name, M U::*member, F func, bool required)
+{
+  return this->BindPrivate(
+    name,
+    [func, member](T& out, const Json::Value* value) -> E {
+      return func(out.*member, value);
+    },
+    required);
+}
+
+template <typename T, typename E>
+template <typename M, typename F>
+cmJSONObjectHelper<T, E>& cmJSONObjectHelper<T, E>::Bind(
+  const cm::string_view& name, std::nullptr_t, F func, bool required)
+{
+  return this->BindPrivate(name,
+                           [func](T& /*out*/, const Json::Value* value) -> E {
+                             M dummy;
+                             return func(dummy, value);
+                           },
+                           required);
+}
+
+template <typename T, typename E>
+cmJSONObjectHelper<T, E>& cmJSONObjectHelper<T, E>::BindPrivate(
+  const cm::string_view& name, MemberFunction&& func, bool required)
+{
+  Member m;
+  m.Name = name;
+  m.Function = std::move(func);
+  m.Required = required;
+  this->Members.push_back(std::move(m));
+  if (required) {
+    this->AnyRequired = true;
+  }
+  return *this;
+}
+
+template <typename T, typename E>
+E cmJSONObjectHelper<T, E>::operator()(T& out, const Json::Value* value) const
+{
+  if (!value && this->AnyRequired) {
+    return this->Fail;
+  }
+  if (value && !value->isObject()) {
+    return this->Fail;
+  }
+  Json::Value::Members extraFields;
+  if (value) {
+    extraFields = value->getMemberNames();
+  }
+
+  for (auto const& m : this->Members) {
+    std::string name(m.Name.data(), m.Name.size());
+    if (value && value->isMember(name)) {
+      E result = m.Function(out, &(*value)[name]);
+      if (result != this->Success) {
+        return result;
+      }
+      extraFields.erase(
+        std::find(extraFields.begin(), extraFields.end(), name));
+    } else if (!m.Required) {
+      E result = m.Function(out, nullptr);
+      if (result != this->Success) {
+        return result;
+      }
+    } else {
+      return this->Fail;
+    }
+  }
+
+  return this->AllowExtra || extraFields.empty() ? this->Success : this->Fail;
+}
+
+template <typename E>
+cmJSONHelper<std::string, E> cmJSONStringHelper(E success, E fail,
+                                                const std::string& defval = "")
+{
+  return
+    [success, fail, defval](std::string& out, const Json::Value* value) -> E {
+      if (!value) {
+        out = defval;
+        return success;
+      }
+      if (!value->isString()) {
+        return fail;
+      }
+      out = value->asString();
+      return success;
+    };
+}
+
+template <typename E>
+cmJSONHelper<int, E> cmJSONIntHelper(E success, E fail, int defval = 0)
+{
+  return [success, fail, defval](int& out, const Json::Value* value) -> E {
+    if (!value) {
+      out = defval;
+      return success;
+    }
+    if (!value->isInt()) {
+      return fail;
+    }
+    out = value->asInt();
+    return success;
+  };
+}
+
+template <typename E>
+cmJSONHelper<unsigned int, E> cmJSONUIntHelper(E success, E fail,
+                                               unsigned int defval = 0)
+{
+  return
+    [success, fail, defval](unsigned int& out, const Json::Value* value) -> E {
+      if (!value) {
+        out = defval;
+        return success;
+      }
+      if (!value->isUInt()) {
+        return fail;
+      }
+      out = value->asUInt();
+      return success;
+    };
+}
+
+template <typename E>
+cmJSONHelper<bool, E> cmJSONBoolHelper(E success, E fail, bool defval = false)
+{
+  return [success, fail, defval](bool& out, const Json::Value* value) -> E {
+    if (!value) {
+      out = defval;
+      return success;
+    }
+    if (!value->isBool()) {
+      return fail;
+    }
+    out = value->asBool();
+    return success;
+  };
+}
+
+template <typename T, typename E, typename F, typename Filter>
+cmJSONHelper<std::vector<T>, E> cmJSONVectorFilterHelper(E success, E fail,
+                                                         F func, Filter filter)
+{
+  return [success, fail, func, filter](std::vector<T>& out,
+                                       const Json::Value* value) -> E {
+    if (!value) {
+      out.clear();
+      return success;
+    }
+    if (!value->isArray()) {
+      return fail;
+    }
+    out.clear();
+    for (auto const& item : *value) {
+      T t;
+      E result = func(t, &item);
+      if (result != success) {
+        return result;
+      }
+      if (!filter(t)) {
+        continue;
+      }
+      out.push_back(t);
+    }
+    return success;
+  };
+}
+
+template <typename T, typename E, typename F>
+cmJSONHelper<std::vector<T>, E> cmJSONVectorHelper(E success, E fail, F func)
+{
+  return cmJSONVectorFilterHelper<T, E, F>(success, fail, func,
+                                           [](const T&) { return true; });
+}
+
+template <typename T, typename E, typename F, typename Filter>
+cmJSONHelper<std::map<std::string, T>, E> cmJSONMapFilterHelper(E success,
+                                                                E fail, F func,
+                                                                Filter filter)
+{
+  return [success, fail, func, filter](std::map<std::string, T>& out,
+                                       const Json::Value* value) -> E {
+    if (!value) {
+      out.clear();
+      return success;
+    }
+    if (!value->isObject()) {
+      return fail;
+    }
+    out.clear();
+    for (auto const& key : value->getMemberNames()) {
+      if (!filter(key)) {
+        continue;
+      }
+      T t;
+      E result = func(t, &(*value)[key]);
+      if (result != success) {
+        return result;
+      }
+      out[key] = std::move(t);
+    }
+    return success;
+  };
+}
+
+template <typename T, typename E, typename F>
+cmJSONHelper<std::map<std::string, T>, E> cmJSONMapHelper(E success, E fail,
+                                                          F func)
+{
+  return cmJSONMapFilterHelper<T, E, F>(
+    success, fail, func, [](const std::string&) { return true; });
+}
+
+template <typename T, typename E, typename F>
+cmJSONHelper<cm::optional<T>, E> cmJSONOptionalHelper(E success, F func)
+{
+  return [success, func](cm::optional<T>& out, const Json::Value* value) -> E {
+    if (!value) {
+      out.reset();
+      return success;
+    }
+    out.emplace();
+    return func(*out, value);
+  };
+}
+
+template <typename T, typename E, typename F>
+cmJSONHelper<T, E> cmJSONRequiredHelper(E fail, F func)
+{
+  return [fail, func](T& out, const Json::Value* value) -> E {
+    if (!value) {
+      return fail;
+    }
+    return func(out, value);
+  };
+}