[vcpkg.cmake] PREPEND CMAKE_FIND_ROOT_PATH (#17336)

* [vcpkg.cmake] PREPEND CMAKE_FIND_ROOT_PATH * [vcpkg.cmake] make PREPEND optional (default off, option VCPKG_PREFER_VCPKG_LIBS) * Apply suggestions from code review Co-authored-by: nicole mazzuca <[email protected]> * Update scripts/buildsystems/vcpkg.cmake Co-authored-by: nicole mazzuca <[email protected]> Co-authored-by: nicole mazzuca <[email protected]>
microsoft · Jun 23, 2021 · 876e67c · 876e67c
1 parent 2ed44b4
commit 876e67c
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Showing 2 changed files with 19 additions and 6 deletions.
diff --git a/docs/users/manifests.md b/docs/users/manifests.md
@@ -425,6 +425,12 @@ Defaults to `OFF`.
 This variable can be set to a list of additional command line parameters to pass to the vcpkg tool during automatic
 installation.
 
+#### `VCPKG_PREFER_SYSTEM_LIBS`
+
+This variable controls whether vcpkg will appends instead of prepends its paths to `CMAKE_PREFIX_PATH`, `CMAKE_LIBRARY_PATH` and `CMAKE_FIND_ROOT_PATH` so that vcpkg libraries/packages are found after toolchain/system libraries/packages.
+
+Defaults to `OFF`.
+
 #### `VCPKG_FEATURE_FLAGS`
 
 This variable can be set to a list of feature flags to pass to the vcpkg tool during automatic installation to opt-in to

diff --git a/scripts/buildsystems/vcpkg.cmake b/scripts/buildsystems/vcpkg.cmake
@@ -47,6 +47,7 @@ mark_as_advanced(VCPKG_VERBOSE)
 option(VCPKG_APPLOCAL_DEPS "Automatically copy dependencies into the output directory for executables." ON)
 option(X_VCPKG_APPLOCAL_DEPS_SERIALIZED "(experimental) Add USES_TERMINAL to VCPKG_APPLOCAL_DEPS to force serialization." OFF)
 option(X_VCPKG_APPLOCAL_DEPS_INSTALL "(experimental) Automatically copy dependencies into the install target directory for executables." OFF)
+option(VCPKG_PREFER_SYSTEM_LIBS "Appends the vcpkg paths to CMAKE_PREFIX_PATH, CMAKE_LIBRARY_PATH and CMAKE_FIND_ROOT_PATH so that vcpkg libraries/packages are found after toolchain/system libraries/packages." OFF)
 
 # Manifest options and settings
 if(NOT DEFINED VCPKG_MANIFEST_DIR)
@@ -379,29 +380,35 @@ set(_VCPKG_INSTALLED_DIR "${VCPKG_INSTALLED_DIR}"
     CACHE PATH
     "The directory which contains the installed libraries for each triplet" FORCE)
 
+if(VCPKG_PREFER_SYSTEM_LIBS)
+    set(Z_VCPKG_PATH_LIST_OP APPEND)
+else()
+    set(Z_VCPKG_PATH_LIST_OP PREPEND)
+endif()
+
 if(CMAKE_BUILD_TYPE MATCHES "^[Dd][Ee][Bb][Uu][Gg]$" OR NOT DEFINED CMAKE_BUILD_TYPE) #Debug build: Put Debug paths before Release paths.
-    list(APPEND CMAKE_PREFIX_PATH
+    list(${Z_VCPKG_PATH_LIST_OP} CMAKE_PREFIX_PATH
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug"
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}"
     )
-    list(APPEND CMAKE_LIBRARY_PATH
+    list(${Z_VCPKG_PATH_LIST_OP} CMAKE_LIBRARY_PATH
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug/lib/manual-link"
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/lib/manual-link"
     )
-    list(APPEND CMAKE_FIND_ROOT_PATH
+    list(${Z_VCPKG_PATH_LIST_OP} CMAKE_FIND_ROOT_PATH
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug"
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}"
     )
 else() #Release build: Put Release paths before Debug paths. Debug Paths are required so that CMake generates correct info in autogenerated target files.
-    list(APPEND CMAKE_PREFIX_PATH
+    list(${Z_VCPKG_PATH_LIST_OP} CMAKE_PREFIX_PATH
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}"
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug"
     )
-    list(APPEND CMAKE_LIBRARY_PATH
+    list(${Z_VCPKG_PATH_LIST_OP} CMAKE_LIBRARY_PATH
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/lib/manual-link"
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug/lib/manual-link"
     )
-    list(APPEND CMAKE_FIND_ROOT_PATH
+    list(${Z_VCPKG_PATH_LIST_OP} CMAKE_FIND_ROOT_PATH
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}"
         "${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}/debug"
     )