From 6e5e9463d2f9673637aa7622368678fab6e74e23 Mon Sep 17 00:00:00 2001
From: Mike Stroyan <stroyan@google.com>
Date: Fri, 16 Sep 2016 09:45:14 -0600
Subject: [PATCH] build: Fix parallel build of layers

Change layer dependencies to prevent collisions of scripts creating headers.
Use dependency on one custom target for each group of headers built by a custom command.
The layers json targets need to depend on the layers targets.
They expect to copy into a directory created by those targets.
Make dependency of vk_safe_struct.cpp indirect through generate_vk_layer_helpers.
That will wait for a single build of the generated files.
---
 layers/CMakeLists.txt | 39 +++++++++++++++++++++++++++++++++++----
 1 file changed, 35 insertions(+), 4 deletions(-)

diff --git a/layers/CMakeLists.txt b/layers/CMakeLists.txt
index 456844f..a5f38f0 100644
--- a/layers/CMakeLists.txt
+++ b/layers/CMakeLists.txt
@@ -40,6 +40,7 @@ if (WIN32)
                     COMMAND copy ${src_json} ${dst_json}
                     VERBATIM
                     )
+                add_dependencies(${config_file}-json ${config_file})
             endforeach(config_file)
         else()
             foreach (config_file ${LAYER_JSON_FILES})
@@ -49,6 +50,7 @@ if (WIN32)
                     COMMAND copy ${src_json} ${dst_json}
                     VERBATIM
                     )
+                add_dependencies(${config_file}-json ${config_file})
             endforeach(config_file)
         endif()
     endif()
@@ -60,6 +62,7 @@ else()
                 COMMAND ln -sf ${CMAKE_CURRENT_SOURCE_DIR}/linux/${config_file}.json
                 VERBATIM
                 )
+                add_dependencies(${config_file}-json ${config_file})
         endforeach(config_file)
     endif()
 endif()
@@ -72,14 +75,14 @@ if (WIN32)
     )
     add_library(VkLayer_${target} SHARED ${ARGN} VkLayer_${target}.def)
     target_link_Libraries(VkLayer_${target} VkLayer_utils)
-    add_dependencies(VkLayer_${target} generate_vk_layer_helpers)
+    add_dependencies(VkLayer_${target} generate_dispatch_table_helper generate_vk_layer_helpers generate_enum_string_helper VkLayer_utils)
     set_target_properties(VkLayer_${target} PROPERTIES LINK_FLAGS "/DEF:${CMAKE_CURRENT_BINARY_DIR}/VkLayer_${target}.def")
     endmacro()
 else()
     macro(add_vk_layer target)
     add_library(VkLayer_${target} SHARED ${ARGN})
     target_link_Libraries(VkLayer_${target} VkLayer_utils)
-    add_dependencies(VkLayer_${target} generate_vk_layer_helpers)
+    add_dependencies(VkLayer_${target} generate_dispatch_table_helper generate_vk_layer_helpers generate_enum_string_helper VkLayer_utils)
     set_target_properties(VkLayer_${target} PROPERTIES LINK_FLAGS "-Wl,-Bsymbolic")
     install(TARGETS VkLayer_${target} DESTINATION ${PROJECT_BINARY_DIR}/install_staging)
     endmacro()
@@ -117,12 +120,40 @@ run_vk_helper(gen_struct_wrappers
     vk_struct_wrappers.h
     vk_struct_wrappers.cpp
     vk_safe_struct.h
+# Don't list vk_safe_struct.cpp as OUTPUT to avoid duplicate builds.
+# If listed here use of it for add_library will cause it to be created
+# independently of custom target generate_vk_layer_helpers .
+# That breaks parallel builds.
+#   vk_safe_struct.cpp
+)
+
+# Let gen_struct_wrappers really create vk_safe_struct.cpp
+add_custom_command(OUTPUT vk_safe_struct.cpp
+    COMMAND echo defer making vk_safe_struct.cpp
+)
+
+set_source_files_properties(
+    vk_struct_string_helper.h
+    vk_struct_string_helper_cpp.h
+    vk_struct_string_helper_no_addr.h
+    vk_struct_string_helper_no_addr_cpp.h
+    vk_struct_size_helper.h
+    vk_struct_size_helper.c
+    vk_struct_wrappers.h
+    vk_struct_wrappers.cpp
+    vk_safe_struct.h
     vk_safe_struct.cpp
+    PROPERTIES GENERATED TRUE)
+
+add_custom_target(generate_enum_string_helper DEPENDS
+    vk_enum_string_helper.h
 )
 
-add_custom_target(generate_vk_layer_helpers DEPENDS
+add_custom_target(generate_dispatch_table_helper DEPENDS
     vk_dispatch_table_helper.h
-    vk_enum_string_helper.h
+)
+
+add_custom_target(generate_vk_layer_helpers DEPENDS
     vk_struct_string_helper.h
     vk_struct_string_helper_no_addr.h
     vk_struct_string_helper_cpp.h
-- 
2.7.4