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# Copyright 2014 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
load(
"@io_bazel_rules_go//go/private:common.bzl",
"SHARED_LIB_EXTENSIONS",
"as_iterable",
"sets",
)
load(
"@io_bazel_rules_go//go/private:mode.bzl",
"LINKMODE_NORMAL",
"LINKMODE_PLUGIN",
)
load(
"@io_bazel_rules_go//go/private:skylib/lib/shell.bzl",
"shell",
)
def _format_archive(d):
return "{}={}={}".format(d.label, d.importmap, d.file.path)
def _map_archive(x):
# Build the set of transitive dependencies. Currently, we tolerate multiple
# archives with the same importmap (though this will be an error in the
# future), but there is a special case which is difficult to avoid:
# If a go_test has internal and external archives, and the external test
# transitively depends on the library under test, we need to exclude the
# library under test and use the internal test archive instead.
deps = depset(transitive = [d.transitive for d in x.archive.direct])
return [
_format_archive(d)
for d in deps.to_list()
if not any([d.importmap == t.importmap for t in x.test_archives])
]
def emit_link(
go,
archive = None,
test_archives = [],
executable = None,
gc_linkopts = [],
version_file = None,
info_file = None):
"""See go/toolchains.rst#link for full documentation."""
if archive == None:
fail("archive is a required parameter")
if executable == None:
fail("executable is a required parameter")
if not go.builders.link:
return _bootstrap_link(go, archive, executable, gc_linkopts)
#TODO: There has to be a better way to work out the rpath
config_strip = len(go._ctx.configuration.bin_dir.path) + 1
pkg_depth = executable.dirname[config_strip:].count("/") + 1
extldflags = list(go.cgo_tools.linker_options)
if go.coverage_enabled:
extldflags.append("--coverage")
gc_linkopts, extldflags = _extract_extldflags(gc_linkopts, extldflags)
builder_args = go.args(go)
tool_args = go.actions.args()
# Add in any mode specific behaviours
extld = go.cgo_tools.compiler_executable
tool_args.add_all(["-extld", extld])
if go.mode.race:
tool_args.add("-race")
if go.mode.msan:
tool_args.add("-msan")
if go.mode.static:
extldflags.append("-static")
if go.mode.link != LINKMODE_NORMAL:
builder_args.add_all(["-buildmode", go.mode.link])
tool_args.add_all(["-linkmode", "external"])
if go.mode.link == LINKMODE_PLUGIN:
tool_args.add_all(["-pluginpath", archive.data.importpath])
builder_args.add_all([struct(archive = archive, test_archives = test_archives)], before_each = "-dep",
map_each = _map_archive)
builder_args.add_all(test_archives, before_each = "-dep", map_each = _format_archive)
# Build a list of rpaths for dynamic libraries we need to find.
# rpaths are relative paths from the binary to directories where libraries
# are stored. Binaries that require these will only work when installed in
# the bazel execroot. Most binaries are only dynamically linked against
# system libraries though.
# TODO: there has to be a better way to work out the rpath.
config_strip = len(go._ctx.configuration.bin_dir.path) + 1
pkg_depth = executable.dirname[config_strip:].count("/") + 1
origin = "@loader_path/" if go.mode.goos == "darwin" else "$ORIGIN/"
base_rpath = origin + "../" * pkg_depth
cgo_dynamic_deps = [
d
for d in archive.cgo_deps.to_list()
if any([d.basename.endswith(ext) for ext in SHARED_LIB_EXTENSIONS])
]
cgo_rpaths = []
for d in cgo_dynamic_deps:
short_dir = d.dirname[len(d.root.path) + len("/"):]
cgo_rpaths.append("-Wl,-rpath,{}/{}".format(base_rpath, short_dir))
cgo_rpaths = sorted({p: None for p in cgo_rpaths}.keys())
extldflags.extend(cgo_rpaths)
# Process x_defs, either adding them directly to linker options, or
# saving them to process through stamping support.
stamp_x_defs = False
for k, v in archive.x_defs.items():
if v.startswith("{") and v.endswith("}"):
builder_args.add_all(["-Xstamp", "%s=%s" % (k, v[1:-1])])
stamp_x_defs = True
else:
tool_args.add_all(["-X", "%s=%s" % (k, v)])
# Stamping support
stamp_inputs = []
if stamp_x_defs:
stamp_inputs = [info_file, version_file]
builder_args.add_all(stamp_inputs, before_each = "-stamp")
builder_args.add_all(["-o", executable])
builder_args.add_all(["-main", archive.data.file])
tool_args.add_all(gc_linkopts)
tool_args.add_all(go.toolchain.flags.link)
if go.mode.strip:
tool_args.add("-w")
tool_args.add_joined("-extldflags", extldflags, join_with = " ")
builder_args.use_param_file("@%s")
builder_args.set_param_file_format("multiline")
go.actions.run(
inputs = sets.union(
archive.libs,
archive.cgo_deps,
go.crosstool,
stamp_inputs,
go.sdk.tools,
go.stdlib.libs,
),
outputs = [executable],
mnemonic = "GoLink",
executable = go.builders.link,
arguments = [builder_args, "--", tool_args],
env = go.env,
)
def _bootstrap_link(go, archive, executable, gc_linkopts):
"""See go/toolchains.rst#link for full documentation."""
inputs = [archive.data.file] + go.sdk.libs + go.sdk.tools + [go.go]
args = go.actions.args()
args.add_all(["tool", "link", "-s", "-linkmode", "internal", "-o", executable])
args.add_all(gc_linkopts)
args.add(archive.data.file)
go.actions.run_shell(
inputs = inputs,
outputs = [executable],
arguments = [args],
mnemonic = "GoLink",
command = "export GOROOT=\"$(pwd)\"/{} && {} \"$@\"".format(shell.quote(go.root), shell.quote(go.go.path)),
env = {
# workaround: go link tool needs some features of gcc to complete the job on Arm platform.
# So, PATH for 'gcc' is required here on Arm platform.
"PATH": go.cgo_tools.compiler_path,
"GOROOT_FINAL": "GOROOT",
},
)
def _extract_extldflags(gc_linkopts, extldflags):
"""Extracts -extldflags from gc_linkopts and combines them into a single list.
Args:
gc_linkopts: a list of flags passed in through the gc_linkopts attributes.
ctx.expand_make_variables should have already been applied. -extldflags
may appear multiple times in this list.
extldflags: a list of flags to be passed to the external linker.
Return:
A tuple containing the filtered gc_linkopts with external flags removed,
and a combined list of external flags. Each string in the returned
extldflags list may contain multiple flags, separated by whitespace.
"""
filtered_gc_linkopts = []
is_extldflags = False
for opt in gc_linkopts:
if is_extldflags:
is_extldflags = False
extldflags.append(opt)
elif opt == "-extldflags":
is_extldflags = True
else:
filtered_gc_linkopts.append(opt)
return filtered_gc_linkopts, extldflags
|
