From 16a0276413f2c0c8a04694a8a8ecfe80498ad4dd Mon Sep 17 00:00:00 2001
From: silvanshade <silvanshade@users.noreply.github.com>
Date: Mon, 31 Mar 2025 14:18:59 -0600
Subject: [PATCH 1/3] Propagate tbb through pkg-config

---
 c/CMakeLists.txt  | 23 +++++++++++++++++++++++
 c/libblake3.pc.in |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/c/CMakeLists.txt b/c/CMakeLists.txt
index c929d71f5..ba3b8559e 100644
--- a/c/CMakeLists.txt
+++ b/c/CMakeLists.txt
@@ -330,6 +330,29 @@ function(join_paths joined_path first_path_segment)
     set(${joined_path} "${temp_path}" PARENT_SCOPE)
 endfunction()
 
+# In-place rewrite a list of strings `requires` into a comma separated string.
+#
+# TODO: Replace function with list(JOIN) when updating to CMake 3.12
+function(join_pkg_config_requires requires)
+  list(LENGTH ${requires} len)
+  set(idx 1)
+  foreach(req ${${requires}})
+    string(APPEND acc ${req})
+    if(idx LESS len)
+      string(APPEND acc ", ")
+    endif()
+    math(EXPR idx "${idx} + 1")
+  endforeach()
+  set(${requires} ${acc} PARENT_SCOPE)
+endfunction()
+
+# calculate pkg-config requirements
+if(BLAKE3_USE_TBB)
+  list(APPEND PKG_CONFIG_REQUIRES "tbb >= ${TBB_VERSION}")
+endif()
+
+# pkg-config support
+join_pkg_config_requires(PKG_CONFIG_REQUIRES)
 join_paths(PKG_CONFIG_INSTALL_LIBDIR "\${prefix}" "${CMAKE_INSTALL_LIBDIR}")
 join_paths(PKG_CONFIG_INSTALL_INCLUDEDIR "\${prefix}" "${CMAKE_INSTALL_INCLUDEDIR}")
 configure_file(libblake3.pc.in libblake3.pc @ONLY)
diff --git a/c/libblake3.pc.in b/c/libblake3.pc.in
index 06f2c7a9b..900913b1f 100644
--- a/c/libblake3.pc.in
+++ b/c/libblake3.pc.in
@@ -7,6 +7,6 @@ Name: @PROJECT_NAME@
 Description: @PROJECT_DESCRIPTION@
 Version: @PROJECT_VERSION@
 
-Requires:
+Requires: @PKG_CONFIG_REQUIRES@
 Libs: -L"${libdir}" -lblake3
 Cflags: -I"${includedir}" @BLAKE3_PKGCONFIG_CFLAGS@

From 510ae9d5339b793b26e9311fba603b556e0bda53 Mon Sep 17 00:00:00 2001
From: silvanshade <silvanshade@users.noreply.github.com>
Date: Mon, 31 Mar 2025 17:48:45 -0600
Subject: [PATCH 2/3] Propagate tbb through CMake config

---
 c/blake3-config.cmake.in | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/c/blake3-config.cmake.in b/c/blake3-config.cmake.in
index 071552be2..92cf395b8 100644
--- a/c/blake3-config.cmake.in
+++ b/c/blake3-config.cmake.in
@@ -1,5 +1,14 @@
 @PACKAGE_INIT@
 
+include(CMakeFindDependencyMacro)
+
+# Remember TBB option state
+set(BLAKE3_USE_TBB @BLAKE3_USE_TBB@)
+
+if(BLAKE3_USE_TBB)
+    find_dependency(TBB @TBB_VERSION@)
+endif()
+
 include("${CMAKE_CURRENT_LIST_DIR}/blake3-targets.cmake")
 
-check_required_components(blake3)
\ No newline at end of file
+check_required_components(blake3)

From 544cedf9ae97e619319b48ad20c89f9c26ac4618 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Ga=C3=9Fmann?=
 <BurningEnlightenment@users.noreply.github.com>
Date: Wed, 2 Apr 2025 18:29:42 +0200
Subject: [PATCH 3/3] refactor: fix a few nits in the join function

The `join_pkg_config_requires` function would misbehave in a few edge cases. Though these edge cases aren't triggered by our current usage.
---
 c/CMakeLists.txt | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/c/CMakeLists.txt b/c/CMakeLists.txt
index ba3b8559e..d7239832b 100644
--- a/c/CMakeLists.txt
+++ b/c/CMakeLists.txt
@@ -334,16 +334,17 @@ endfunction()
 #
 # TODO: Replace function with list(JOIN) when updating to CMake 3.12
 function(join_pkg_config_requires requires)
-  list(LENGTH ${requires} len)
+  set(_requires "${${requires}}") # avoid shadowing issues, e.g. "${requires}"=len
+  list(LENGTH "${requires}" len)
   set(idx 1)
-  foreach(req ${${requires}})
-    string(APPEND acc ${req})
+  foreach(req IN LISTS _requires)
+    string(APPEND acc "${req}")
     if(idx LESS len)
       string(APPEND acc ", ")
     endif()
     math(EXPR idx "${idx} + 1")
   endforeach()
-  set(${requires} ${acc} PARENT_SCOPE)
+  set("${requires}" "${acc}" PARENT_SCOPE)
 endfunction()
 
 # calculate pkg-config requirements