cmake-presets: add ${pathListSep} macro

Fixes: #23282

Help/manual/cmake-presets.7.rst

@@ -1068,6 +1068,17 @@ Recognized macros include:
 
   A literal dollar sign (``$``).
 
+``${pathListSep}``
+
+  Native character for separating lists of paths, such as ``:`` or ``;``.
+
+  For example, by setting ``PATH`` to
+  ``/path/to/ninja/bin${pathListSep}$env{PATH}``, ``${pathListSep}`` will
+  expand to the underlying operating system's character used for
+  concatenation in ``PATH``.
+
+  This is allowed in preset files specifying version ``5`` or above.
+
 ``$env{<variable-name>}``
 
   Environment variable with name ``<variable-name>``. The variable name may

Help/release/dev/presets-pathListSep.rst

@@ -0,0 +1,5 @@
+presets-pathListSep
+-------------------
+
+* :manual:`cmake-presets(7)` files now support a ``${pathListSep}`` macro,
+  which expands to ``:`` or ``;`` based on the platform.

Source/cmCMakePresetsGraph.cxx

@@ -361,6 +361,13 @@ bool ExpandMacros(const cmCMakePresetsGraph& graph, const T& preset,
           cmSystemTools::GetParentDirectory(preset.OriginFile->Filename);
         return ExpandMacroResult::Ok;
       }
+      if (macroName == "pathListSep") {
+        if (version < 5) {
+          return ExpandMacroResult::Error;
+        }
+        macroOut += cmSystemTools::GetSystemPathlistSeparator();
+        return ExpandMacroResult::Ok;
+      }
     }
 
     return ExpandMacroResult::Ignore;

Source/cmSystemTools.cxx

@@ -3429,3 +3429,12 @@ cm::string_view cmSystemTools::GetSystemName()
   return "";
 #endif
 }
+
+char cmSystemTools::GetSystemPathlistSeparator()
+{
+#if defined(_WIN32)
+  return ';';
+#else
+  return ':';
+#endif
+}

Source/cmSystemTools.h

@@ -535,6 +535,9 @@ public:
   /** Get the system name. */
   static cm::string_view GetSystemName();
 
+  /** Get the system path separator character */
+  static char GetSystemPathlistSeparator();
+
 private:
   static bool s_ForceUnixPaths;
   static bool s_RunCommandHideConsole;

Tests/RunCMake/CMakePresets/PathListSep.cmake

@@ -0,0 +1,7 @@
+include(${CMAKE_CURRENT_LIST_DIR}/TestVariable.cmake)
+
+if(CMAKE_HOST_WIN32)
+    test_variable(TEST_PATH_LIST_SEP "" "${CMAKE_CURRENT_SOURCE_DIR};${CMAKE_CURRENT_SOURCE_DIR}")
+else()
+    test_variable(TEST_PATH_LIST_SEP "" "${CMAKE_CURRENT_SOURCE_DIR}:${CMAKE_CURRENT_SOURCE_DIR}")
+endif()

Tests/RunCMake/CMakePresets/PathListSep.json.in

@@ -0,0 +1,13 @@
+{
+    "version": 5,
+    "configurePresets": [
+        {
+            "name": "PathListSep",
+            "generator": "@RunCMake_GENERATOR@",
+            "binaryDir": "${sourceDir}/build",
+            "cacheVariables": {
+                "TEST_PATH_LIST_SEP": "${sourceDir}${pathListSep}${sourceDir}"
+            }
+        }
+    ]
+}

Tests/RunCMake/CMakePresets/PathListSepFuture-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/CMakePresets/PathListSepFuture-stderr.txt

@@ -0,0 +1,2 @@
+^CMake Error: Could not read presets from [^
+]*/Tests/RunCMake/CMakePresets/PathListSepFuture: Invalid macro expansion$

Tests/RunCMake/CMakePresets/PathListSepFuture.json.in

@@ -0,0 +1,13 @@
+{
+    "version": 4,
+    "configurePresets": [
+        {
+            "name": "PathListSepFuture",
+            "generator": "@RunCMake_GENERATOR@",
+            "binaryDir": "${sourceDir}/build",
+            "cacheVariables": {
+                "TEST_PATH_LIST_SEP": "${sourceDir}${pathListSep}${sourceDir}"
+            }
+        }
+    ]
+}

Tests/RunCMake/CMakePresets/RunCMakeTest.cmake

@@ -335,6 +335,12 @@ unset(CMakePresets_EXTRA_FILES)
 set(CMakePresets_FILE "${RunCMake_SOURCE_DIR}/FileDirFuture.json.in")
 run_cmake_presets(FileDirFuture)
 
+# Test ${pathListSep} macro
+set(CMakePresets_FILE "${RunCMake_SOURCE_DIR}/PathListSep.json.in")
+run_cmake_presets(PathListSep)
+set(CMakePresets_FILE "${RunCMake_SOURCE_DIR}/PathListSepFuture.json.in")
+run_cmake_presets(PathListSepFuture)
+
 # Test conditions
 set(CMakePresets_FILE "${RunCMake_SOURCE_DIR}/Conditions.json.in")
 run_cmake_presets(ListConditions --list-presets)