From 9ad5336d831fd650050784bcb553a02087289e6b Mon Sep 17 00:00:00 2001
From: Bartek Kryza <bkryza@gmail.com>
Date: Thu, 30 May 2024 21:22:59 +0200
Subject: [PATCH] Added documentation about clang-uml-wrapped script for Nix

---
 docs/common_options.md    | 9 +++++++++
 docs/troubleshooting.md   | 6 +++---
 packaging/nix/default.nix | 2 +-
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/docs/common_options.md b/docs/common_options.md
index c8fea3ba..83abcf84 100644
--- a/docs/common_options.md
+++ b/docs/common_options.md
@@ -11,6 +11,7 @@
   * [Use '--query-driver' command line option](#use---query-driver-command-line-option)
   * [Manually add and remove compile flags from the compilation database](#manually-add-and-remove-compile-flags-from-the-compilation-database)
   * [Using 'CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES'](#using-cmake_cxx_implicit_include_directories)
+  * [Nix wrapper](#nix-wrapper)
 
 <!-- tocstop -->
 
@@ -224,4 +225,12 @@ Yet another option, for CMake based projects, is to use the following CMake opti
 set(CMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES ${CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES})
 ```
 
+### Nix wrapper
+On NixOS or when using `nix`, `clang-uml` provides a wrapper script called
+`clang-uml-wrapped`, which builds and exports `CPATH` and `CPLUS_INCLUDE_PATH`
+environment variables before running `clang-uml`, which contain valid
+system header Clang paths for the current Nix environment.
 
+The `clang-uml-wrapped` script can be called the same way as `clang-uml` and
+should resolve the system include paths without the need for any of the above
+solutions.
diff --git a/docs/troubleshooting.md b/docs/troubleshooting.md
index 014c6c38..858b78da 100644
--- a/docs/troubleshooting.md
+++ b/docs/troubleshooting.md
@@ -11,8 +11,8 @@
   * [Cannot generate diagrams from header-only projects](#cannot-generate-diagrams-from-header-only-projects)
   * [YAML anchors and aliases are not fully supported](#yaml-anchors-and-aliases-are-not-fully-supported)
   * [Schema validation error is thrown, but the configuration file is correct](#schema-validation-error-is-thrown-but-the-configuration-file-is-correct)
-* [Class diagrams](#class-diagrams)
   * ["fatal error: 'stddef.h' file not found"](#fatal-error-stddefh-file-not-found)
+* [Class diagrams](#class-diagrams)
   * [How can I generate class diagram of my entire project](#how-can-i-generate-class-diagram-of-my-entire-project)
   * [Cannot generate classes for 'std' namespace](#cannot-generate-classes-for-std-namespace)
 * [Sequence diagrams](#sequence-diagrams)
@@ -224,8 +224,6 @@ schema validation, and exits if the configuration file is invalid.
 In case there is a bug in the schema validation, the schema validation
 step can be skipped by providing `--no-validate` command line option.
 
-## Class diagrams
-
 ### "fatal error: 'stddef.h' file not found"
 
 This error means that Clang cannot find some standard headers in include
@@ -285,6 +283,8 @@ clang-uml --add-compile-flag -I/opt/my_toolchain/include \
 Also see
 [here](./md_docs_2common__options.html#resolving-include-path-and-compiler-flags-issues).
 
+## Class diagrams
+
 ### How can I generate class diagram of my entire project
 
 I want to generate a diagram containing all classes and relationships in my
diff --git a/packaging/nix/default.nix b/packaging/nix/default.nix
index 56fa5594..f6571b2c 100644
--- a/packaging/nix/default.nix
+++ b/packaging/nix/default.nix
@@ -32,7 +32,7 @@ stdenv.mkDerivation {
   postInstall = ''
     export unwrapped_clang_uml="$out/bin/clang-uml"
     
-    # inject clang and unwrapp_clang_uml variables into wrapper
+    # inject clang and unwrap_clang_uml variables into wrapper
     substituteAll ${./wrapper} $out/bin/clang-uml-wrapped
     chmod +x $out/bin/clang-uml-wrapped