Merge pull request #606 from capnproto/fix-capnp-generate-cpp-src-prefix

Fix capnp_generate_cpp usage of --src-prefix

c++/cmake/CapnProtoMacros.cmake

@@ -15,7 +15,7 @@
 #       Directory to place compiled schema sources (default: CMAKE_CURRENT_BINARY_DIR).
 #   CAPNPC_IMPORT_DIRS
 #       List of additional include directories for the schema compiler.
-#       (CMAKE_CURRENT_SOURCE_DIR and CAPNP_INCLUDE_DIRECTORY are always included.)
+#       (CAPNPC_SRC_PREFIX and CAPNP_INCLUDE_DIRECTORY are always included.)
 #   CAPNPC_SRC_PREFIX
 #       Schema file source prefix (default: CMAKE_CURRENT_SOURCE_DIR).
 #   CAPNPC_FLAGS
@@ -45,17 +45,6 @@ function(CAPNP_GENERATE_CPP SOURCES HEADERS)
     message(SEND_ERROR "Could not locate capnp header files (CAPNP_INCLUDE_DIRECTORY).")
   endif()
 
-  # Default compiler includes
-  set(include_path -I ${CMAKE_CURRENT_SOURCE_DIR} -I ${CAPNP_INCLUDE_DIRECTORY})
-
-  if(DEFINED CAPNPC_IMPORT_DIRS)
-    # Append each directory as a series of '-I' flags in ${include_path}
-    foreach(directory ${CAPNPC_IMPORT_DIRS})
-      get_filename_component(absolute_path "${directory}" ABSOLUTE)
-      list(APPEND include_path -I ${absolute_path})
-    endforeach()
-  endif()
-
   if(DEFINED CAPNPC_OUTPUT_DIR)
     # Prepend a ':' to get the format for the '-o' flag right
     set(output_dir ":${CAPNPC_OUTPUT_DIR}")
@@ -68,6 +57,22 @@ function(CAPNP_GENERATE_CPP SOURCES HEADERS)
   endif()
   get_filename_component(CAPNPC_SRC_PREFIX "${CAPNPC_SRC_PREFIX}" ABSOLUTE)
 
+  # Default compiler includes. Note that in capnp's own test usage of capnp_generate_cpp(), these
+  # two variables will end up evaluating to the same directory. However, it's difficult to
+  # deduplicate them because if CAPNP_INCLUDE_DIRECTORY came from the capnp_tool target property,
+  # then it must be a generator expression in order to handle usages in both the build tree and the
+  # install tree. This vastly overcomplicates duplication detection, so the duplication doesn't seem
+  # worth fixing.
+  set(include_path -I "${CAPNPC_SRC_PREFIX}" -I "${CAPNP_INCLUDE_DIRECTORY}")
+
+  if(DEFINED CAPNPC_IMPORT_DIRS)
+    # Append each directory as a series of '-I' flags in ${include_path}
+    foreach(directory ${CAPNPC_IMPORT_DIRS})
+      get_filename_component(absolute_path "${directory}" ABSOLUTE)
+      list(APPEND include_path -I "${absolute_path}")
+    endforeach()
+  endif()
+
   set(${SOURCES})
   set(${HEADERS})
   foreach(schema_file ${ARGN})

c++/cmake/FindCapnProto.cmake

-#
-# Finds the Cap'n Proto libraries, and compiles schema files.
-#
-# Configuration variables (optional):
-#   CAPNPC_OUTPUT_DIR
-#       Directory to place compiled schema sources (default: the same directory as the schema file).
-#   CAPNPC_IMPORT_DIRS
-#       List of additional include directories for the schema compiler.
-#       (CMAKE_CURRENT_SOURCE_DIR and CAPNP_INCLUDE_DIRS are always included.)
-#   CAPNPC_SRC_PREFIX
-#       Schema file source prefix (default: CMAKE_CURRENT_SOURCE_DIR).
-#   CAPNPC_FLAGS
-#       Additional flags to pass to the schema compiler.
-#
-# Variables that are discovered:
-#   CAPNP_EXECUTABLE
-#       Path to the `capnp` tool (can be set to override).
-#   CAPNPC_CXX_EXECUTABLE
-#       Path to the `capnpc-c++` tool (can be set to override).
-#   CAPNP_INCLUDE_DIRS
-#       Include directories for the library's headers (can be set to override).
-#   CANP_LIBRARIES
-#       The Cap'n Proto library paths.
-#   CAPNP_LIBRARIES_LITE
-#       Paths to only the 'lite' libraries.
-#   CAPNP_DEFINITIONS
-#       Compiler definitions required for building with the library.
-#   CAPNP_FOUND
-#       Set if the libraries have been located.
-#
-# Example usage:
-#
-#   find_package(CapnProto REQUIRED)
-#   include_directories(${CAPNP_INCLUDE_DIRS})
-#   add_definitions(${CAPNP_DEFINITIONS})
-#
-#   capnp_generate_cpp(CAPNP_SRCS CAPNP_HDRS schema.capnp)
-#   add_executable(a a.cc ${CAPNP_SRCS} ${CAPNP_HDRS})
-#   target_link_library(a ${CAPNP_LIBRARIES})
-#
-# For out-of-source builds:
-#
-#   set(CAPNPC_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR})
-#   include_directories(${CAPNPC_OUTPUT_DIR})
-#   capnp_generate_cpp(...)
-#
-
-# CAPNP_GENERATE_CPP ===========================================================
-
-function(CAPNP_GENERATE_CPP SOURCES HEADERS)
-  if(NOT ARGN)
-    message(SEND_ERROR "CAPNP_GENERATE_CPP() called without any source files.")
-  endif()
-  if(NOT CAPNP_EXECUTABLE)
-    message(SEND_ERROR "Could not locate capnp executable (CAPNP_EXECUTABLE).")
-  endif()
-  if(NOT CAPNPC_CXX_EXECUTABLE)
-    message(SEND_ERROR "Could not locate capnpc-c++ executable (CAPNPC_CXX_EXECUTABLE).")
-  endif()
-  if(NOT CAPNP_INCLUDE_DIRS)
-    message(SEND_ERROR "Could not locate capnp header files (CAPNP_INCLUDE_DIRS).")
-  endif()
-
-  # Default compiler includes
-  set(include_path -I ${CMAKE_CURRENT_SOURCE_DIR} -I ${CAPNP_INCLUDE_DIRS})
-
-  if(DEFINED CAPNPC_IMPORT_DIRS)
-    # Append each directory as a series of '-I' flags in ${include_path}
-    foreach(directory ${CAPNPC_IMPORT_DIRS})
-      get_filename_component(absolute_path "${directory}" ABSOLUTE)
-      list(APPEND include_path -I ${absolute_path})
-    endforeach()
-  endif()
-
-  if(DEFINED CAPNPC_OUTPUT_DIR)
-    # Prepend a ':' to get the format for the '-o' flag right
-    set(output_dir ":${CAPNPC_OUTPUT_DIR}")
-  else()
-    set(output_dir ":.")
-  endif()
-
-  if(NOT DEFINED CAPNPC_SRC_PREFIX)
-    set(CAPNPC_SRC_PREFIX "${CMAKE_CURRENT_SOURCE_DIR}")
-  endif()
-  get_filename_component(CAPNPC_SRC_PREFIX "${CAPNPC_SRC_PREFIX}" ABSOLUTE)
-
-  set(${SOURCES})
-  set(${HEADERS})
-  foreach(schema_file ${ARGN})
-    get_filename_component(file_path "${schema_file}" ABSOLUTE)
-    get_filename_component(file_dir "${file_path}" PATH)
-
-    # Figure out where the output files will go
-    if (NOT DEFINED CAPNPC_OUTPUT_DIR)
-      set(output_base "${file_path}")
-    else()
-      # Output files are placed in CAPNPC_OUTPUT_DIR, at a location as if they were
-      # relative to CAPNPC_SRC_PREFIX.
-      string(LENGTH "${CAPNPC_SRC_PREFIX}" prefix_len)
-      string(SUBSTRING "${file_path}" 0 ${prefix_len} output_prefix)
-      if(NOT "${CAPNPC_SRC_PREFIX}" STREQUAL "${output_prefix}")
-        message(SEND_ERROR "Could not determine output path for '${schema_file}' ('${file_path}') with source prefix '${CAPNPC_SRC_PREFIX}' into '${CAPNPC_OUTPUT_DIR}'.")
-      endif()
-
-      string(SUBSTRING "${file_path}" ${prefix_len} -1 output_path)
-      set(output_base "${CAPNPC_OUTPUT_DIR}${output_path}")
-    endif()
-
-    add_custom_command(
-      OUTPUT "${output_base}.c++" "${output_base}.h"
-      COMMAND "${CAPNP_EXECUTABLE}"
-      ARGS compile 
-          -o ${CAPNPC_CXX_EXECUTABLE}${output_dir}
-          --src-prefix ${CAPNPC_SRC_PREFIX}
-          ${include_path}
-          ${CAPNPC_FLAGS}
-          ${file_path}
-      DEPENDS "${schema_file}"
-      COMMENT "Compiling Cap'n Proto schema ${schema_file}"
-      VERBATIM
-    )
-    list(APPEND ${SOURCES} "${output_base}.c++")
-    list(APPEND ${HEADERS} "${output_base}.h")
-  endforeach()
-
-  set_source_files_properties(${${SOURCES}} ${${HEADERS}} PROPERTIES GENERATED TRUE)
-  set(${SOURCES} ${${SOURCES}} PARENT_SCOPE)
-  set(${HEADERS} ${${HEADERS}} PARENT_SCOPE)
-endfunction()
-
-# Find Libraries/Paths =========================================================
-
-# Use pkg-config to get path hints and definitions
-find_package(PkgConfig QUIET)
-pkg_check_modules(PKGCONFIG_CAPNP capnp)
-pkg_check_modules(PKGCONFIG_CAPNP_RPC capnp-rpc QUIET)
-pkg_check_modules(PKGCONFIG_CAPNP_JSON capnp-json QUIET)
-
-find_library(CAPNP_LIB_KJ kj
-  HINTS "${PKGCONFIG_CAPNP_LIBDIR}" ${PKGCONFIG_CAPNP_LIBRARY_DIRS}
-)
-find_library(CAPNP_LIB_KJ-ASYNC kj-async
-  HINTS "${PKGCONFIG_CAPNP_RPC_LIBDIR}" ${PKGCONFIG_CAPNP_RPC_LIBRARY_DIRS}
-)
-find_library(CAPNP_LIB_CAPNP capnp
-  HINTS "${PKGCONFIG_CAPNP_LIBDIR}" ${PKGCONFIG_CAPNP_LIBRARY_DIRS}
-)
-find_library(CAPNP_LIB_CAPNP-RPC capnp-rpc
-  HINTS "${PKGCONFIG_CAPNP_RPC_LIBDIR}" ${PKGCONFIG_CAPNP_RPC_LIBRARY_DIRS}
-)
-find_library(CAPNP_LIB_CAPNP-JSON capnp-json
-  HINTS "${PKGCONFIG_CAPNP_JSON_LIBDIR}" ${PKGCONFIG_CAPNP_JSON_LIBRARY_DIRS}
-)
-mark_as_advanced(CAPNP_LIB_KJ CAPNP_LIB_KJ-ASYNC CAPNP_LIB_CAPNP CAPNP_LIB_CAPNP-RPC CAPNP_LIB_CAPNP-JSON)
-set(CAPNP_LIBRARIES_LITE
-  ${CAPNP_LIB_CAPNP}
-  ${CAPNP_LIB_KJ}
-)
-set(CAPNP_LIBRARIES
-  ${CAPNP_LIB_CAPNP-JSON}
-  ${CAPNP_LIB_CAPNP-RPC}
-  ${CAPNP_LIB_CAPNP}
-  ${CAPNP_LIB_KJ-ASYNC}
-  ${CAPNP_LIB_KJ}
-)
-
-# Was only the 'lite' library found?
-if(CAPNP_LIB_CAPNP AND NOT CAPNP_LIB_CAPNP-RPC)
-  set(CAPNP_DEFINITIONS -DCAPNP_LITE)
-else()
-  set(CAPNP_DEFINITIONS)
-endif()
-
-find_path(CAPNP_INCLUDE_DIRS capnp/generated-header-support.h
-  HINTS "${PKGCONFIG_CAPNP_INCLUDEDIR}" ${PKGCONFIG_CAPNP_INCLUDE_DIRS}
-)
-
-find_program(CAPNP_EXECUTABLE
-  NAMES capnp
-  DOC "Cap'n Proto Command-line Tool"
-  HINTS "${PKGCONFIG_CAPNP_PREFIX}/bin"
-)
-
-find_program(CAPNPC_CXX_EXECUTABLE
-  NAMES capnpc-c++
-  DOC "Capn'n Proto C++ Compiler"
-  HINTS "${PKGCONFIG_CAPNP_PREFIX}/bin"
-)
-
-# Only *require* the include directory, libkj, and libcapnp. If compiling with
-# CAPNP_LITE, nothing else will be found.
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(CAPNP DEFAULT_MSG
-  CAPNP_INCLUDE_DIRS
-  CAPNP_LIB_KJ
-  CAPNP_LIB_CAPNP
-)

c++/src/capnp/CMakeLists.txt

@@ -194,13 +194,23 @@ if(BUILD_TESTING)
     test-import2.capnp
   )
 
-  # Add "/capnp" to match the path used to import the files in the test sources
-  set(CAPNPC_OUTPUT_DIR "${CMAKE_CURRENT_BINARY_DIR}/test_capnp/capnp")
-  include_directories("${CMAKE_CURRENT_BINARY_DIR}/test_capnp")  # Note: no "/capnp"
+  set(CAPNPC_OUTPUT_DIR "${CMAKE_CURRENT_BINARY_DIR}/test_capnp")
+  include_directories("${CAPNPC_OUTPUT_DIR}")
   file(MAKE_DIRECTORY "${CAPNPC_OUTPUT_DIR}")
+  # Tell capnp_generate_cpp to set --src-prefix to our parent directory. This allows us to pass our
+  # .capnp files relative to this directory, but have their canonical name end up as
+  # capnp/test.capnp, capnp/test-import.capnp, etc.
+  get_filename_component(CAPNPC_SRC_PREFIX "${CMAKE_CURRENT_SOURCE_DIR}" DIRECTORY)
 
   capnp_generate_cpp(test_capnp_cpp_files test_capnp_h_files ${test_capnp_files})
 
+  # TODO(cleanup): capnp-tests and capnp-heavy-tests both depend on the test.capnp output files. In
+  #   a parallel Makefile-based build (maybe others?), they can race and cause the custom capnp
+  #   command in capnp_generate_cpp() to run twice. To get around this I'm using a custom target to
+  #   force CMake to generate race-free Makefiles. Remove this garbage when we move to a
+  #   target-based capnp_generate() command, as that will make CMake do the right thing by default.
+  add_custom_target(test_capnp DEPENDS ${test_capnp_cpp_files} ${test_capnp_h_files})
+
   if(CAPNP_LITE)
     set(test_libraries capnp kj-test kj)
   else()
@@ -226,6 +236,7 @@ if(BUILD_TESTING)
     ${test_capnp_h_files}
   )
   target_link_libraries(capnp-tests ${test_libraries})
+  add_dependencies(capnp-tests test_capnp)
   add_dependencies(check capnp-tests)
   add_test(NAME capnp-tests-run COMMAND capnp-tests)
 
@@ -258,6 +269,7 @@ if(BUILD_TESTING)
       )
     endif()
 
+    add_dependencies(capnp-heavy-tests test_capnp)
     add_dependencies(check capnp-heavy-tests)
     add_test(NAME capnp-heavy-tests-run COMMAND capnp-heavy-tests)