Enable cross-directory ccache (#1539)

* Add support for cross-directory ccaching

* Add gdb alias for ffdb

* Update proj

* Change from fdebug-prefix-map to ffile-prefix-map to fix __FILE__ issues

* Remove unnecessary stuff from ffdb nix file

* Remove commented-out code

.flake/pkgs/ffdb/default.nix

@@ -0,0 +1,40 @@
+{ lib
+, stdenv
+, makeWrapper
+, gdb
+, python3
+, proj
+}:
+
+stdenv.mkDerivation rec {
+  pname = "ffdb";
+  version = "0.1";
+
+  pythonPath = with python3.pkgs; makePythonPath [
+    proj
+  ];
+
+  dontBuild = true;
+
+  nativeBuildInputs = [ makeWrapper ];
+
+  src = ./.;
+
+  installPhase = ''
+    mkdir -p $out/share/ffdb
+    cp ffdb.py $out/share/ffdb
+    makeWrapper ${gdb}/bin/gdb $out/bin/gdb \
+      --add-flags "-q -x $out/share/ffdb/ffdb.py" \
+      --set NIX_PYTHONPATH ${pythonPath} \
+      --prefix PATH : ${lib.makeBinPath [
+        python3
+      ]}
+    cp $out/bin/gdb $out/bin/ffdb
+  '';
+
+  nativeCheckInputs = [
+    gdb
+    python3
+    proj
+  ];
+}

.flake/pkgs/ffdb/ffdb.py

@@ -0,0 +1,7 @@
+from proj.config_file import get_config_root
+from pathlib import Path
+import gdb
+
+gdb.execute(f'directory {get_config_root(Path.cwd())}')
+gdb.prompt_hook = lambda x: '(ffdb) '
+gdb.execute('set history save on')

.gitignore

@@ -1,3 +1,6 @@
+# gdb history
+.gdb_history
+
 # dtgen files
 *.dtg.cc
 *.dtg.h

cmake/flexflow-utils.cmake

@@ -39,7 +39,7 @@ function(ff_set_cxx_properties target)
       CXX_EXTENSIONS NO
   )
   target_compile_options(${target}
-    PRIVATE $<$<COMPILE_LANGUAGE:CXX>:> # add C++ compile flags here
+    PRIVATE $<$<COMPILE_LANGUAGE:CXX>:> "-ffile-prefix-map=${CMAKE_SOURCE_DIR}=." # add C++ compile flags here
   )
 endfunction()
 

flake.nix

@@ -35,10 +35,13 @@
       mkShell = pkgs.mkShell.override {
         stdenv = pkgs.cudaPackages.backendStdenv;
       };
+
+      proj = proj-repo.packages.${system}.proj;
     in 
     {
       packages = {
         legion = pkgs.callPackage ./.flake/pkgs/legion.nix { };
+        ffdb = pkgs.callPackage ./.flake/pkgs/ffdb { inherit proj; };
         hpp2plantuml = pkgs.python3Packages.callPackage ./.flake/pkgs/hpp2plantuml.nix { };
         rapidcheckFull = pkgs.symlinkJoin {
           name = "rapidcheckFull";
@@ -102,9 +105,7 @@
               doxygen
               lcov # for code coverage
             ])
-            (with proj-repo.packages.${system}; [
-              proj
-            ])
+            [ proj ]
             (with self.packages.${system}; [
               legion
               hpp2plantuml
@@ -128,7 +129,6 @@
               gh-markdown-preview
               shellcheck
               plantuml
-              gdb
               ruff
               compdb
               jq
@@ -148,6 +148,9 @@
               black
               toml
             ])
+            (with self.packages.${system}; [
+              ffdb
+            ])
           ];
         };
       };