@ -3,12 +3,32 @@
load ( " @rules_cc//cc:action_names.bzl " , cc_action_names = " ACTION_NAMES " )
load ( " @rules_cc//cc:find_cc_toolchain.bzl " , " find_cc_toolchain " )
################################################################################
# Archive/linking support
################################################################################
def _collect_linker_input_objects ( dep_label , cc_info , objs , pic_objs ) :
""" Accumulate .o and .pic.o files into `objs` and `pic_objs`. """
link_ctx = cc_info . linking_context
if link_ctx == None :
return
linker_inputs = link_ctx . linker_inputs . to_list ( )
for link_input in linker_inputs :
if link_input . owner != dep_label :
# This is a transitive dep: skip it.
continue
for lib in link_input . libraries :
objs . extend ( lib . objects or [ ] )
pic_objs . extend ( lib . pic_objects or [ ] )
# Creates an action to build the `output_file` static library (archive)
# using `object_files`.
def _create_archive_action (
ctx ,
feature_configuration ,
cc_toolchain ,
cc_toolchain_info ,
output_file ,
object_files ) :
# Based on Bazel's src/main/starlark/builtins_bzl/common/cc/cc_import.bzl:
@ -16,7 +36,7 @@ def _create_archive_action(
# Build the command line and add args for all of the input files:
archiver_variables = cc_common . create_link_variables (
feature_configuration = feature_configuration ,
cc_toolchain = cc_toolchain ,
cc_toolchain = cc_toolchain_info ,
output_file = output_file . path ,
is_using_linker = False ,
)
@ -48,7 +68,7 @@ def _create_archive_action(
inputs = depset (
direct = object_files ,
transitive = [
cc_toolchain . all_files ,
cc_toolchain_info . all_files ,
] ,
) ,
use_default_shell_env = False ,
@ -56,96 +76,242 @@ def _create_archive_action(
mnemonic = " CppArchiveDist " ,
)
# Implementation for cc_dist_library rule.
def _cc_dist_library_impl ( ctx ) :
cc_toolchain_info = find_cc_toolchain ( ctx )
if cc_toolchain_info . ar_executable == None :
return [ ]
feature_configuration = cc_common . configure_features (
ctx = ctx ,
def _create_dso_link_action (
ctx ,
feature_configuration ,
cc_toolchain_info ,
object_files ,
pic_object_files ) :
compilation_outputs = cc_common . create_compilation_outputs (
objects = depset ( object_files ) ,
pic_objects = depset ( pic_object_files ) ,
)
link_output = cc_common . link (
actions = ctx . actions ,
feature_configuration = feature_configuration ,
cc_toolchain = cc_toolchain_info ,
compilation_outputs = compilation_outputs ,
name = ctx . label . name ,
output_type = " dynamic_library " ,
user_link_flags = ctx . attr . linkopts ,
)
library_to_link = link_output . library_to_link
outputs = [ ]
# Note: library_to_link.dynamic_library and interface_library are often
# symlinks in the solib directory. For DefaultInfo, prefer reporting
# the resolved artifact paths.
if library_to_link . resolved_symlink_dynamic_library != None :
outputs . append ( library_to_link . resolved_symlink_dynamic_library )
elif library_to_link . dynamic_library != None :
outputs . append ( library_to_link . dynamic_library )
if library_to_link . resolved_symlink_interface_library != None :
outputs . append ( library_to_link . resolved_symlink_interface_library )
elif library_to_link . interface_library != None :
outputs . append ( library_to_link . interface_library )
return outputs
################################################################################
# Source file/header support
################################################################################
# Collect the set of object files from the immediate deps.
CcFileList = provider (
doc = " List of files to be built into a library. " ,
fields = {
# As a rule of thumb, `hdrs` and `textual_hdrs` are the files that
# would be installed along with a prebuilt library.
" hdrs " : " public header files, including those used by generated code " ,
" textual_hdrs " : " files which are included but are not self-contained " ,
# The `internal_hdrs` are header files which appear in `srcs`.
# These are only used when compiling the library.
" internal_hdrs " : " internal header files (only used to build .cc files) " ,
" srcs " : " source files " ,
} ,
)
def _flatten_target_files ( targets ) :
return depset ( transitive = [ target . files for target in targets ] )
files = [ ]
for target in targets :
files . extend ( target . files . to_list ( ) )
return files
def _cc_file_list_aspect_impl ( target , ctx ) :
# Extract sources from a `cc_library` (or similar):
if CcInfo not in target :
return [ ]
# We're going to reach directly into the attrs on the traversed rule.
rule_attr = ctx . rule . attr
# CcInfo is a proxy for what we expect this rule to look like.
# However, some deps may expose `CcInfo` without having `srcs`,
# `hdrs`, etc., so we use `getattr` to handle that gracefully.
internal_hdrs = [ ]
srcs = [ ]
# Filter `srcs` so it only contains source files. Headers will go
# into `internal_headers`.
for src in _flatten_target_files ( getattr ( rule_attr , " srcs " , [ ] ) ) . to_list ( ) :
if src . extension . lower ( ) in [ " c " , " cc " , " cpp " , " cxx " ] :
srcs . append ( src )
else :
internal_hdrs . append ( src )
return [ CcFileList (
hdrs = _flatten_target_files ( getattr ( rule_attr , " hdrs " , depset ( ) ) ) ,
textual_hdrs = _flatten_target_files ( getattr (
rule_attr ,
" textual_hdrs " ,
depset ( ) ,
) ) ,
internal_hdrs = depset ( internal_hdrs ) ,
srcs = depset ( srcs ) ,
) ]
cc_file_list_aspect = aspect (
doc = """
Aspect to provide the list of sources and headers from a rule .
Output is CcFileList . Example :
cc_library (
name = " foo " ,
srcs = [
" foo.cc " ,
" foo_internal.h " ,
] ,
hdrs = [ " foo.h " ] ,
textual_hdrs = [ " foo_inl.inc " ] ,
)
# produces:
# CcFileList(
# hdrs = depset([File("foo.h")]),
# textual_hdrs = depset([File("foo_inl.inc")]),
# internal_hdrs = depset([File("foo_internal.h")]),
# srcs = depset([File("foo.cc")]),
# )
""" ,
implementation = _cc_file_list_aspect_impl ,
)
################################################################################
# Rule impl
################################################################################
def _collect_inputs ( deps ) :
""" Collects files from a list of immediate deps.
This rule collects source files and linker inputs for C + + deps . Only
these immediate deps are considered , not transitive deps .
The return value is a struct with object files ( linker inputs ) ,
partitioned by PIC and non - pic , and the rules ' source and header files:
struct (
objects = . . . , # non-PIC object files
pic_objects = . . . , # PIC objects
cc_file_list = . . . , # a CcFileList
)
Args :
deps : Iterable of immediate deps . These will be treated as the " inputs, "
but not the transitive deps .
Returns :
A struct with linker inputs , source files , and header files .
"""
objs = [ ]
pic_objs = [ ]
for dep in ctx . attr . deps :
if CcInfo not in dep :
continue
link_ctx = dep [ CcInfo ] . linking_context
if link_ctx == None :
continue
# The returned CcFileList will contain depsets of the deps' file lists.
# These lists hold `depset()`s from each of `deps`.
srcs = [ ]
hdrs = [ ]
internal_hdrs = [ ]
textual_hdrs = [ ]
linker_inputs = link_ctx . linker_inputs . to_list ( )
for link_input in linker_inputs :
if link_input . owner != dep . label :
# This is a transitive dep: skip it.
continue
for dep in deps :
if CcInfo in dep :
_collect_linker_input_objects (
dep . label ,
dep [ CcInfo ] ,
objs ,
pic_objs ,
)
for lib in link_input . libraries :
objs . extend ( lib . objects or [ ] )
pic_objs . extend ( lib . pic_objects or [ ] )
if CcFileList in dep :
cfl = dep [ CcFileList ]
srcs . append ( cfl . srcs )
hdrs . append ( cfl . hdrs )
internal_hdrs . append ( cfl . internal_hdrs )
textual_hdrs . append ( cfl . textual_hdrs )
return struct (
objects = objs ,
pic_objects = pic_objs ,
cc_file_list = CcFileList (
srcs = depset ( transitive = srcs ) ,
hdrs = depset ( transitive = hdrs ) ,
internal_hdrs = depset ( transitive = internal_hdrs ) ,
textual_hdrs = depset ( transitive = textual_hdrs ) ,
) ,
)
# Implementation for cc_dist_library rule.
def _cc_dist_library_impl ( ctx ) :
cc_toolchain_info = find_cc_toolchain ( ctx )
feature_configuration = cc_common . configure_features (
ctx = ctx ,
cc_toolchain = cc_toolchain_info ,
)
inputs = _collect_inputs ( ctx . attr . deps )
# For static libraries, build separately with and without pic.
stemname = " lib " + ctx . label . name
outputs = [ ]
if len ( objs ) > 0 :
if len ( inputs . object s ) > 0 :
archive_out = ctx . actions . declare_file ( stemname + " .a " )
_create_archive_action (
ctx ,
feature_configuration ,
cc_toolchain_info ,
archive_out ,
objs ,
inputs . object s ,
)
outputs . append ( archive_out )
if len ( pic_objs ) > 0 :
if len ( inputs . pic_object s ) > 0 :
pic_archive_out = ctx . actions . declare_file ( stemname + " .pic.a " )
_create_archive_action (
ctx ,
feature_configuration ,
cc_toolchain_info ,
pic_archive_out ,
pic_objs ,
inputs . pic_object s ,
)
outputs . append ( pic_archive_out )
# For dynamic libraries, use the `cc_common.link` command to ensure
# everything gets built correctly according to toolchain definitions.
compilation_outputs = cc_common . create_compilation_outputs (
objects = depset ( objs ) ,
pic_objects = depset ( pic_objs ) ,
)
link_output = cc_common . link (
actions = ctx . actions ,
feature_configuration = feature_configuration ,
cc_toolchain = cc_toolchain_info ,
compilation_outputs = compilation_outputs ,
name = ctx . label . name ,
output_type = " dynamic_library " ,
user_link_flags = ctx . attr . linkopts ,
)
library_to_link = link_output . library_to_link
# Note: library_to_link.dynamic_library and interface_library are often
# symlinks in the solib directory. For DefaultInfo, prefer reporting
# the resolved artifact paths.
if library_to_link . resolved_symlink_dynamic_library != None :
outputs . append ( library_to_link . resolved_symlink_dynamic_library )
elif library_to_link . dynamic_library != None :
outputs . append ( library_to_link . dynamic_library )
if library_to_link . resolved_symlink_interface_library != None :
outputs . append ( library_to_link . resolved_symlink_interface_library )
elif library_to_link . interface_library != None :
outputs . append ( library_to_link . interface_library )
outputs . extend ( _create_dso_link_action (
ctx ,
feature_configuration ,
cc_toolchain_info ,
inputs . objects ,
inputs . pic_objects ,
) )
# We could expose the libraries for use from cc rules:
#
@ -169,6 +335,7 @@ def _cc_dist_library_impl(ctx):
return [
DefaultInfo ( files = depset ( outputs ) ) ,
inputs . cc_file_list ,
]
cc_dist_library = rule (
@ -214,6 +381,7 @@ Example:
" Only these targets ' compilation outputs will be " +
" included (i.e., the transitive dependencies are not " +
" included in the output). " ) ,
aspects = [ cc_file_list_aspect ] ,
) ,
" linkopts " : attr . string_list (
doc = ( " Add these flags to the C++ linker command when creating " +
David L. Jones
3 years ago
committed by
GitHub