Makefiles Generators: use compiler for dependencies generation

Each source compilation generates a dependencies file. These dependencies
files are consolidated in one file per target. This consolidation is done
as part of command 'cmake -E cmake_depends` launched before evaluation of
makefile dependency graph.

The consolidation uses the same approach as `CMake` dependencies management.

Fixes: #21321

1 files changed, 60 insertions, 0 deletions

diff --git a/Source/cmDependsCompiler.h b/Source/cmDependsCompiler.h
new file mode 100644
index 0000000..838156d
--- /dev/null
+++ b/Source/cmDependsCompiler.h
@@ -0,0 +1,60 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#pragma once
+
+#include "cmConfigure.h" // IWYU pragma: keep
+
+#include <functional>
+#include <iosfwd>
+#include <string>
+#include <vector>
+
+#include "cmDepends.h"
+
+class cmLocalUnixMakefileGenerator3;
+
+/** \class cmDepends
+ * \brief Dependencies files manager.
+ *
+ * This class is responsible for maintaining a compiler_depends.make file in
+ * the build tree corresponding to an object file.
+ */
+class cmDependsCompiler
+{
+public:
+  cmDependsCompiler() = default;
+  ~cmDependsCompiler() = default;
+
+  /** should this be verbose in its output */
+  void SetVerbose(bool verb) { this->Verbose = verb; }
+
+  /** Set the local generator for the directory in which we are
+      scanning dependencies.  This is not a full local generator; it
+      has been setup to do relative path conversions for the current
+      directory.  */
+  void SetLocalGenerator(cmLocalUnixMakefileGenerator3* lg)
+  {
+    this->LocalGenerator = lg;
+  }
+
+  /** Read dependencies for the target file. Return true if
+      dependencies didn't changed and false if not.
+      Up-to-date Dependencies will be stored in deps. */
+  bool CheckDependencies(
+    const std::string& internalDepFile,
+    const std::vector<std::string>& depFiles,
+    cmDepends::DependencyMap& dependencies,
+    const std::function<bool(const std::string&)>& isValidPath);
+
+  /** Write dependencies for the target file.  */
+  void WriteDependencies(const cmDepends::DependencyMap& dependencies,
+                         std::ostream& makeDepends,
+                         std::ostream& internalDepends);
+
+  /** Clear dependencies for the target so they will be regenerated.  */
+  void ClearDependencies(const std::vector<std::string>& depFiles);
+
+private:
+  bool Verbose = false;
+  cmLocalUnixMakefileGenerator3* LocalGenerator = nullptr;
+};