"""Utilities for module and path manipulations."""
load("@bazel_skylib//lib:paths.bzl", "paths")
load(":private/set.bzl", "set")
def module_name(hs, f, rel_path = None):
"""Given Haskell source file path, turn it into a dot-separated module name.
module_name(
hs,
"some-workspace/some-package/src/Foo/Bar/Baz.hs",
) => "Foo.Bar.Baz"
Args:
hs: Haskell context.
f: Haskell source file.
rel_path: Explicit relative path from import root to the module, or None
if it should be deduced.
Returns:
string: Haskell module name.
"""
rpath = rel_path
if not rpath:
rpath = _rel_path_to_module(hs, f)
(hsmod, _) = paths.split_extension(rpath.replace("/", "."))
return hsmod
def target_unique_name(hs, name_prefix):
"""Make a target-unique name.
`name_prefix` is made target-unique by adding a rule name
suffix to it. This means that given two different rules, the same
`name_prefix` is distinct. Note that this is does not disambiguate two
names within the same rule. Given a haskell_library with name foo
you could expect:
target_unique_name(hs, "libdir") => "libdir-foo"
This allows two rules using same name_prefix being built in same
environment to avoid name clashes of their output files and directories.
Args:
hs: Haskell context.
name_prefix: Template for the name.
Returns:
string: Target-unique name_prefix.
"""
return "{0}-{1}".format(name_prefix, hs.name)
def module_unique_name(hs, source_file, name_prefix):
"""Make a target- and module- unique name.
module_unique_name(
hs,
"some-workspace/some-package/src/Foo/Bar/Baz.hs",
"libdir"
) => "libdir-foo-Foo.Bar.Baz"
This is quite similar to `target_unique_name` but also uses a path built
from `source_file` to prevent clashes with other names produced using the
same `name_prefix`.
Args:
hs: Haskell context.
source_file: Source file name.
name_prefix: Template for the name.
Returns:
string: Target- and source-unique name.
"""
return "{0}-{1}".format(
target_unique_name(hs, name_prefix),
module_name(hs, source_file),
)
def declare_compiled(hs, src, ext, directory = None, rel_path = None):
"""Given a Haskell-ish source file, declare its output.
Args:
hs: Haskell context.
src: Haskell source file.
ext: New extension.
directory: String, directory prefix the new file should live in.
rel_path: Explicit relative path from import root to the module, or None
if it should be deduced.
Returns:
File: Declared output file living in `directory` with given `ext`.
"""
rpath = rel_path
if not rpath:
rpath = _rel_path_to_module(hs, src)
fp = paths.replace_extension(rpath, ext)
fp_with_dir = fp if directory == None else paths.join(directory, fp)
return hs.actions.declare_file(fp_with_dir)
def make_path(libs, prefix = None, sep = None):
"""Return a string value for using as LD_LIBRARY_PATH or similar.
Args:
libs: List of library files that should be available
prefix: String, an optional prefix to add to every path.
sep: String, the path separator, defaults to ":".
Returns:
String: paths to the given library directories separated by ":".
"""
r = set.empty()
sep = sep if sep else ":"
for lib in libs:
lib_dir = paths.dirname(lib.path)
if prefix:
lib_dir = paths.join(prefix, lib_dir)
set.mutable_insert(r, lib_dir)
return sep.join(set.to_list(r))
def darwin_convert_to_dylibs(hs, libs):
"""Convert .so dynamic libraries to .dylib.
Bazel's cc_library rule will create .so files for dynamic libraries even
on MacOS. GHC's builtin linker, which is used during compilation, GHCi,
or doctests, hard-codes the assumption that all dynamic libraries on MacOS
end on .dylib. This function serves as an adaptor and produces symlinks
from a .dylib version to the .so version for every dynamic library
dependencies that does not end on .dylib.
Args:
hs: Haskell context.
libs: List of library files dynamic or static.
Returns:
List of library files where all dynamic libraries end on .dylib.
"""
lib_prefix = "_dylibs"
new_libs = []
for lib in libs:
if is_shared_library(lib) and lib.extension != "dylib":
dylib_name = paths.join(
target_unique_name(hs, lib_prefix),
lib.dirname,
"lib" + get_lib_name(lib) + ".dylib",
)
dylib = hs.actions.declare_file(dylib_name)
ln(hs, lib, dylib)
new_libs.append(dylib)
else:
new_libs.append(lib)
return new_libs
def windows_convert_to_dlls(hs, libs):
"""Convert .so dynamic libraries to .dll.
Bazel's cc_library rule will create .so files for dynamic libraries even
on Windows. GHC's builtin linker, which is used during compilation, GHCi,
or doctests, hard-codes the assumption that all dynamic libraries on Windows
end on .dll. This function serves as an adaptor and produces symlinks
from a .dll version to the .so version for every dynamic library
dependencies that does not end on .dll.
Args:
hs: Haskell context.
libs: List of library files dynamic or static.
Returns:
List of library files where all dynamic libraries end on .dll.
"""
lib_prefix = "_dlls"
new_libs = []
for lib in libs:
if is_shared_library(lib) and lib.extension != "dll":
dll_name = paths.join(
target_unique_name(hs, lib_prefix),
paths.dirname(lib.short_path),
"lib" + get_lib_name(lib) + ".dll",
)
dll = hs.actions.declare_file(dll_name)
ln(hs, lib, dll)
new_libs.append(dll)
else:
new_libs.append(lib)
return new_libs
def get_lib_name(lib):
"""Return name of library by dropping extension and "lib" prefix.
Args:
lib: The library File.
Returns:
String: name of library.
"""
base = lib.basename[3:] if lib.basename[:3] == "lib" else lib.basename
n = base.find(".so.")
end = paths.replace_extension(base, "") if n == -1 else base[:n]
return end
def link_libraries(libs_to_link, args):
"""Add linker flags to link against the given libraries.
Args:
libs_to_link: List of library Files.
args: Append arguments to this list.
Returns:
List of library names that were linked.
"""
seen_libs = set.empty()
libraries = []
for lib in libs_to_link:
lib_name = get_lib_name(lib)
if not set.is_member(seen_libs, lib_name):
set.mutable_insert(seen_libs, lib_name)
args += ["-l{0}".format(lib_name)]
libraries.append(lib_name)
def is_shared_library(f):
"""Check if the given File is a shared library.
Args:
f: The File to check.
Returns:
Bool: True if the given file `f` is a shared library, False otherwise.
"""
return f.extension in ["so", "dylib"] or f.basename.find(".so.") != -1
def is_static_library(f):
"""Check if the given File is a static library.
Args:
f: The File to check.
Returns:
Bool: True if the given file `f` is a static library, False otherwise.
"""
return f.extension in ["a"]
def _rel_path_to_module(hs, f):
"""Make given file name relative to the directory where the module hierarchy
starts.
_rel_path_to_module(
"some-workspace/some-package/src/Foo/Bar/Baz.hs"
) => "Foo/Bar/Baz.hs"
Args:
hs: Haskell context.
f: Haskell source file.
Returns:
string: Relative path to module file.
"""
# If it's a generated file, strip off the bin or genfiles prefix.
path = f.path
if path.startswith(hs.bin_dir.path):
path = paths.relativize(path, hs.bin_dir.path)
elif path.startswith(hs.genfiles_dir.path):
path = paths.relativize(path, hs.genfiles_dir.path)
return paths.relativize(path, hs.src_root)
# TODO Consider merging with paths.relativize. See
# https://github.com/bazelbuild/bazel-skylib/pull/44.
def _truly_relativize(target, relative_to):
"""Return a relative path to `target` from `relative_to`.
Args:
target: string, path to directory we want to get relative path to.
relative_to: string, path to directory from which we are starting.
Returns:
string: relative path to `target`.
"""
t_pieces = target.split("/")
r_pieces = relative_to.split("/")
common_part_len = 0
for tp, rp in zip(t_pieces, r_pieces):
if tp == rp:
common_part_len += 1
else:
break
result = [".."] * (len(r_pieces) - common_part_len)
result += t_pieces[common_part_len:]
return "/".join(result)
def ln(hs, target, link, extra_inputs = depset()):
"""Create a symlink to target.
Args:
hs: Haskell context.
extra_inputs: extra phony dependencies of symlink.
Returns:
None
"""
relative_target = _truly_relativize(target.path, link.dirname)
hs.actions.run_shell(
inputs = depset([target], transitive = [extra_inputs]),
outputs = [link],
mnemonic = "Symlink",
command = "ln -s {target} {link}".format(
target = relative_target,
link = link.path,
),
use_default_shell_env = True,
)
def link_forest(ctx, srcs, basePath = ".", **kwargs):
"""Write a symlink to each file in `srcs` into a destination directory
defined using the same arguments as `ctx.actions.declare_directory`"""
local_files = []
for src in srcs.to_list():
dest = ctx.actions.declare_file(
paths.join(basePath, src.basename),
**kwargs
)
local_files.append(dest)
ln(ctx, src, dest)
return local_files
def copy_all(ctx, srcs, dest):
"""Copy all the files in `srcs` into `dest`"""
if list(srcs.to_list()) == []:
ctx.actions.run_shell(
command = "mkdir -p {dest}".format(dest = dest.path),
outputs = [dest],
)
else:
args = ctx.actions.args()
args.add_all(srcs)
ctx.actions.run_shell(
inputs = depset(srcs),
outputs = [dest],
mnemonic = "Copy",
command = "mkdir -p {dest} && cp -L -R \"$@\" {dest}".format(dest = dest.path),
arguments = [args],
)
def parse_pattern(ctx, pattern_str):
"""Parses a string label pattern.
Args:
ctx: Standard Bazel Rule context.
pattern_str: The pattern to parse.
Patterns are absolute labels in the local workspace. E.g.
`//some/package:some_target`. The following wild-cards are allowed:
`...`, `:all`, and `:*`. Also the `//some/package` shortcut is allowed.
Returns:
A struct of
package: A list of package path components. May end on the wildcard `...`.
target: The target name. None if the package ends on `...`. May be one
of the wildcards `all` or `*`.
NOTE: it would be better if Bazel itself exposed this functionality to Starlark.
Any feature using this function should be marked as experimental, until the
resolution of https://github.com/bazelbuild/bazel/issues/7763.
"""
# We only load targets in the local workspace anyway. So, it's never
# necessary to specify a workspace. Therefore, we don't allow it.
if pattern_str.startswith("@"):
fail("Invalid haskell_repl pattern. Patterns may not specify a workspace. They only apply to the current workspace")
# To keep things simple, all patterns have to be absolute.
if not pattern_str.startswith("//"):
if not pattern_str.startswith(":"):
fail("Invalid haskell_repl pattern. Patterns must start with either '//' or ':'.")
# if the pattern string doesn't start with a package (it starts with :, e.g. :two),
# then we prepend the contextual package
pattern_str = "//{package}{target}".format(package = ctx.label.package, target = pattern_str)
# Separate package and target (if present).
package_target = pattern_str[2:].split(":", maxsplit = 2)
package_str = package_target[0]
target_str = None
if len(package_target) == 2:
target_str = package_target[1]
# Parse package pattern.
package = []
dotdotdot = False # ... has to be last component in the pattern.
for s in package_str.split("/"):
if dotdotdot:
fail("Invalid haskell_repl pattern. ... has to appear at the end.")
if s == "...":
dotdotdot = True
package.append(s)
# Parse target pattern.
if dotdotdot:
if target_str != None:
fail("Invalid haskell_repl pattern. ... has to appear at the end.")
elif target_str == None:
if len(package) > 0 and package[-1] != "":
target_str = package[-1]
else:
fail("Invalid haskell_repl pattern. The empty string is not a valid target.")
return struct(
package = package,
target = target_str,
)
def match_label(patterns, label):
"""Whether the given local workspace label matches any of the patterns.
Args:
patterns: A list of parsed patterns to match the label against.
Apply `parse_pattern` before passing patterns into this function.
label: Match this label against the patterns.
Returns:
A boolean. True if the label is in the local workspace and matches any of
the given patterns. False otherwise.
NOTE: it would be better if Bazel itself exposed this functionality to Starlark.
Any feature using this function should be marked as experimental, until the
resolution of https://github.com/bazelbuild/bazel/issues/7763.
"""
# Only local workspace labels can match.
# Despite the docs saying otherwise, labels don't have a workspace_name
# attribute. So, we use the workspace_root. If it's empty, the target is in
# the local workspace. Otherwise, it's an external target.
if label.workspace_root != "":
return False
package = label.package.split("/")
target = label.name
# Match package components.
for i in range(min(len(patterns.package), len(package))):
if patterns.package[i] == "...":
return True
elif patterns.package[i] != package[i]:
return False
# If no wild-card or mismatch was encountered, the lengths must match.
# Otherwise, the label's package is not covered.
if len(patterns.package) != len(package):
return False
# Match target.
if patterns.target == "all" or patterns.target == "*":
return True
else:
return patterns.target == target
