compilers: Use enum for for deupdlication returns in CompilerArgs

pull/7369/head
Dylan Baker 5 years ago
parent d6c6b933c4
commit b887212bee
  1. 63
      mesonbuild/compilers/compilers.py

@ -18,6 +18,7 @@ from collections import deque
import itertools
import typing as T
from functools import lru_cache
import enum
from ..linkers import (
GnuLikeDynamicLinkerMixin, LinkerEnvVarsMixin, SolarisDynamicLinker,
@ -409,6 +410,28 @@ class RunResult:
self.stdout = stdout
self.stderr = stderr
class Dedup(enum.Enum):
"""What kind of deduplication can be done to compiler args.
OVERRIDEN - Whether an argument can be 'overridden' by a later argument.
For example, -DFOO defines FOO and -UFOO undefines FOO. In this case,
we can safely remove the previous occurrence and add a new one. The
same is true for include paths and library paths with -I and -L.
UNIQUE - Arguments that once specified cannot be undone, such as `-c` or
`-pipe`. New instances of these can be completely skipped.
NO_DEDUP - Whether it matters where or how many times on the command-line
a particular argument is present. This can matter for symbol
resolution in static or shared libraries, so we cannot de-dup or
reorder them.
"""
NO_DEDUP = 0
UNIQUE = 1
OVERRIDEN = 2
class CompilerArgs(collections.abc.MutableSequence):
'''
List-like class that manages a list of compiler arguments. Should be used
@ -486,13 +509,13 @@ class CompilerArgs(collections.abc.MutableSequence):
dedup = self._can_dedup(a)
if a not in pre_flush_set:
pre_flush.append(a)
if dedup == 2:
if dedup is Dedup.OVERRIDEN:
pre_flush_set.add(a)
for a in reversed(self.post):
dedup = self._can_dedup(a)
if a not in post_flush_set:
post_flush.appendleft(a)
if dedup == 2:
if dedup is Dedup.OVERRIDEN:
post_flush_set.add(a)
#pre and post will overwrite every element that is in the container
@ -551,29 +574,15 @@ class CompilerArgs(collections.abc.MutableSequence):
@classmethod
@lru_cache(maxsize=None)
def _can_dedup(cls, arg):
'''
Returns whether the argument can be safely de-duped. This is dependent
on three things:
a) Whether an argument can be 'overridden' by a later argument. For
example, -DFOO defines FOO and -UFOO undefines FOO. In this case, we
can safely remove the previous occurrence and add a new one. The same
is true for include paths and library paths with -I and -L. For
these we return `2`. See `dedup2_prefixes` and `dedup2_args`.
b) Arguments that once specified cannot be undone, such as `-c` or
`-pipe`. New instances of these can be completely skipped. For these
we return `1`. See `dedup1_prefixes` and `dedup1_args`.
c) Whether it matters where or how many times on the command-line
a particular argument is present. This can matter for symbol
resolution in static or shared libraries, so we cannot de-dup or
reorder them. For these we return `0`. This is the default.
def _can_dedup(cls, arg: str) -> Dedup:
"""Returns whether the argument can be safely de-duped.
In addition to these, we handle library arguments specially.
With GNU ld, we surround library arguments with -Wl,--start/end-group
With GNU ld, we surround library arguments with -Wl,--start/end-gr -> Dedupoup
to recursively search for symbols in the libraries. This is not needed
with other linkers.
'''
"""
# A standalone argument must never be deduplicated because it is
# defined by what comes _after_ it. Thus dedupping this:
# -D FOO -D BAR
@ -583,7 +592,7 @@ class CompilerArgs(collections.abc.MutableSequence):
# FOO -D BAR
# both of which are invalid.
if arg in cls.dedup2_prefixes:
return 0
return Dedup.NO_DEDUP
if arg.startswith('-L='):
# DMD and LDC proxy all linker arguments using -L=; in conjunction
# with ld64 on macOS this can lead to command line arguments such
@ -592,17 +601,17 @@ class CompilerArgs(collections.abc.MutableSequence):
# spaces and quoting does not work. if we deduplicate these then
# one of the -L=0 arguments will be removed and the version
# argument will consume the next argument instead.
return 0
return Dedup.NO_DEDUP
if arg in cls.dedup2_args or \
arg.startswith(cls.dedup2_prefixes) or \
arg.endswith(cls.dedup2_suffixes):
return 2
return Dedup.OVERRIDEN
if arg in cls.dedup1_args or \
arg.startswith(cls.dedup1_prefixes) or \
arg.endswith(cls.dedup1_suffixes) or \
re.search(cls.dedup1_regex, arg):
return 1
return 0
return Dedup.UNIQUE
return Dedup.NO_DEDUP
@classmethod
@lru_cache(maxsize=None)
@ -725,7 +734,7 @@ class CompilerArgs(collections.abc.MutableSequence):
# previous occurrence of it and adding a new one, or not adding the
# new occurrence.
dedup = self._can_dedup(arg)
if dedup == 1:
if dedup is Dedup.UNIQUE:
# Argument already exists and adding a new instance is useless
if arg in self.__container or arg in self.pre or arg in self.post:
continue

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