Refactor: Move some common code into separate file

This code is going to be needed by both cmCMakePresetsFile and
cmCMakePresetsFileReadJSON when the upcoming condition types are
created. Move it into a header file.

Source/CMakeLists.txt

@@ -198,6 +198,7 @@ set(SRCS
   cmCMakePath.cxx
   cmCMakePresetsFile.cxx
   cmCMakePresetsFile.h
+  cmCMakePresetsFileInternal.h
   cmCMakePresetsFileReadJSON.cxx
   cmCommandArgumentParserHelper.cxx
   cmCommonTargetGenerator.cxx

Source/cmCMakePresetsFile.cxx

@@ -9,16 +9,10 @@
 #include <iterator>
 #include <utility>
 
+#include "cmCMakePresetsFileInternal.h"
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 
-#define CHECK_OK(expr)                                                        \
-  {                                                                           \
-    auto _result = expr;                                                      \
-    if (_result != ReadFileResult::READ_OK)                                   \
-      return _result;                                                         \
-  }
-
 #define CHECK_EXPAND(out, field, expanders, version)                          \
   {                                                                           \
     switch (ExpandMacros(field, expanders, version)) {                        \
@@ -44,6 +38,8 @@ using ReadFileResult = cmCMakePresetsFile::ReadFileResult;
 using ConfigurePreset = cmCMakePresetsFile::ConfigurePreset;
 using BuildPreset = cmCMakePresetsFile::BuildPreset;
 using TestPreset = cmCMakePresetsFile::TestPreset;
+using ExpandMacroResult = cmCMakePresetsFileInternal::ExpandMacroResult;
+using MacroExpander = cmCMakePresetsFileInternal::MacroExpander;
 
 void InheritString(std::string& child, const std::string& parent)
 {
@@ -166,16 +162,6 @@ bool IsValidMacroNamespace(const std::string& str)
     [&str](const char* prefix) -> bool { return str == prefix; });
 }
 
-enum class ExpandMacroResult
-{
-  Ok,
-  Ignore,
-  Error,
-};
-
-using MacroExpander = std::function<ExpandMacroResult(
-  const std::string&, const std::string&, std::string&, int version)>;
-
 ExpandMacroResult VisitEnv(std::string& value, CycleStatus& status,
                            const std::vector<MacroExpander>& macroExpanders,
                            int version);

Source/cmCMakePresetsFileInternal.h

@@ -0,0 +1,22 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "cmCMakePresetsFile.h"
+
+#define CHECK_OK(expr)                                                        \
+  {                                                                           \
+    auto _result = expr;                                                      \
+    if (_result != ReadFileResult::READ_OK)                                   \
+      return _result;                                                         \
+  }
+
+namespace cmCMakePresetsFileInternal {
+enum class ExpandMacroResult
+{
+  Ok,
+  Ignore,
+  Error,
+};
+
+using MacroExpander = std::function<ExpandMacroResult(
+  const std::string&, const std::string&, std::string&, int version)>;
+}