fetchDeps: Add flags for pre-built repos

Add --v-headers-root, --spirv-cross-root,
and --glslang-root options with an arg that allow
caller to pass in the root dir of these three
repos if the caller already has them.  The script
then symlinks to these instead of fetching and building.

fetchDependencies

@@ -4,12 +4,54 @@
 #
 # fetchDependencies - Retrieves the correct versions of all dependencies
 #
-# macOS usage: ./fetchDependencies
+# macOS usage: ./fetchDependencies [--v-headers-root path] [--spirv-cross-root path] [--glslang-root path]
+#
+#      --v-headers-root path
+#              "path" specific a directory path to a
+#              KhronosGroup/Vulkan-Headers repository.
+#              This repository does not have to be built.
+#
+#      --spirv-cross-root path
+#              "path" specifies a directory path to a
+#              KhronosGroup/SPIRV-Cross repository.
+#              This repository does not have to be built.
+#
+#      --glslang-root path
+#              "path" specifies a directory path to a KhronosGroup/glslang
+#              repository.  This repository does need to be built and the
+#              build directory must be in the specified directory.
+#              It should be built the same way this script builds it.
+#
 #
 
 
 # ----------------- Functions -------------------
 
+V_HEADERS_ROOT=""
+SPIRV_CROSS_ROOT=""
+GLSLANG_ROOT=""
+
+while (( "$#" )); do
+  case "$1" in
+       --v-headers-root)
+         V_HEADERS_ROOT=$2
+         shift 2
+         ;;
+       --spirv-cross-root)
+         SPIRV_CROSS_ROOT=$2
+         shift 2
+         ;;
+       --glslang-root)
+         GLSLANG_ROOT=$2
+         shift 2
+         ;;
+       -*|--*=)
+         echo "Error: Unsupported flag $1" >&2
+         exit 1
+         ;;
+  esac
+done
+
 # Update a repository. If it exists, fetch it, if not clone it.
 # $1 repo name
 # $2 repo url
@@ -76,35 +118,59 @@ update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
 
 # ----------------- Vulkan-Headers -------------------
 
-REPO_NAME=Vulkan-Headers
-REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
-REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
+# When MoltenVK is built by something that alread has a copy of the
+# Vulkan-Headers repo, use it by creating a symlink.
+if [ ! "$V_HEADERS_ROOT" = "" ]; then
+       REPO_NAME=Vulkan-Headers
+       rm -rf ${REPO_NAME}
+       ln -sfn ${V_HEADERS_ROOT} ${REPO_NAME}
+else
+       REPO_NAME=Vulkan-Headers
+       REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
+       REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
 
-update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
+       update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
+fi
 
 
 # ----------------- SPIRV-Cross -------------------
 
-REPO_NAME=SPIRV-Cross
-REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
-REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
+# When MoltenVK is built by something that alread has a copy of the
+# Vulkan-Headers repo, use it by creating a symlink.
+if [ ! "$SPIRV_CROSS_ROOT" = "" ]; then
+       REPO_NAME=SPIRV-Cross
+       rm -rf ${REPO_NAME}
+       ln -sfn ${SPIRV_CROSS_ROOT} ${REPO_NAME}
+else
+       REPO_NAME=SPIRV-Cross
+       REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
+       REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
 
-update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
+       update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
+fi
 
 
 # ----------------- glslang -------------------
 
-REPO_NAME=glslang
-REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
-REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
+# When MoltenVK is built by something that alread has a copy of the
+# Vulkan-Headers repo, use it by creating a symlink.
+if [ ! "$GLSLANG_ROOT" = "" ]; then
+       REPO_NAME=glslang
+       rm -rf ${REPO_NAME}
+       ln -sfn ${GLSLANG_ROOT} ${REPO_NAME}
+else
+       REPO_NAME=glslang
+       REPO_URL="https://github.com/KhronosGroup/${REPO_NAME}.git"
+       REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
 
-update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
+       update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
 
-cd ${REPO_NAME}
-./update_glslang_sources.py
-cd -
+       cd ${REPO_NAME}
+       ./update_glslang_sources.py
+       cd -
 
-build_repo ${REPO_NAME}
+       build_repo ${REPO_NAME}
+fi
 
 
 # ----------------- Vulkan-Tools -------------------
@@ -115,7 +181,6 @@ REPO_REV=$(cat "../${EXT_REV_DIR}/${REPO_NAME}_repo_revision")
 
 update_repo ${REPO_NAME} ${REPO_URL} ${REPO_REV}
 
-
 # ----------------- VulkanSamples -------------------
 
 REPO_NAME=VulkanSamples