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-rw-r--r--third_party/bazel/rules_haskell/debug/linking_utils/ldd.py288
1 files changed, 0 insertions, 288 deletions
diff --git a/third_party/bazel/rules_haskell/debug/linking_utils/ldd.py b/third_party/bazel/rules_haskell/debug/linking_utils/ldd.py
deleted file mode 100644
index 897cfdc713d3..000000000000
--- a/third_party/bazel/rules_haskell/debug/linking_utils/ldd.py
+++ /dev/null
@@ -1,288 +0,0 @@
-import subprocess
-import os
-import sys
-import re
-
-
-### helper functions
-
-def list_to_dict(f, l):
-    """dict with elements of list as keys & as values transformed by f"""
-    d = {}
-    for el in l:
-        d[el] = f(el)
-    return d
-
-def dict_remove_empty(d):
-    """remove keys that have [] or {} or as values"""
-    new = {}
-    for k, v in d.items():
-        if not (v == [] or v == {}):
-             new[k] = v
-    return new
-
-def identity(x):
-    """identity function"""
-    return x
-
-def const(x):
-    """(curried) constant function"""
-    def f(y):
-        return x
-    return f
-
-def memoized(cache, f, arg):
-    """Memoizes a call to `f` with `arg` in the dict `cache`.
-    Modifies the cache dict in place."""
-    res = cache.get(arg)
-    if arg in cache:
-        return cache[arg]
-    else:
-        res = f(arg)
-        cache[arg] = res
-        return res
-
-### IO functions that find elf dependencies
-
-_field_matcher = re.compile(b"  ([A-Z0-9_]+) +(.*)$")
-
-def read_dynamic_fields(elf_path):
-    """Read the dynamic header fields from an elf binary
-
-    Args:
-      elf_path: path to the elf binary (either absolute or relative to pwd)
-
-    Returns:
-      a list [(field_key, field_value)] where field_keys could appear multiple
-      times (for example there's usually more than one NEEDED field).
-    """
-    res = subprocess.check_output([
-        # force locale to C for stable output
-        "env", "LC_ALL=C",
-        "objdump",
-        # specifying the section brings execution time down from 150ms to 10ms
-        "--section=.dynamic",
-        "--all-headers",
-        elf_path
-    ])
-    to_end = res.split(b"Dynamic Section:\n")[1]
-    # to first empty line
-    dyn_section = to_end[: 1 + to_end.find(b"\n\n")]
-    def read_dynamic_field(s):
-        """return (field_key, field_value)"""
-        return _field_matcher.match(s).groups()
-    return list(map(read_dynamic_field, dyn_section.splitlines(True)))
-
-def __query_dynamic_fields(df, key):
-    """takes a list of dynamic field tuples (key and value),
-    where keys can appear multiple times, and returns a list of all
-    values with the given key (in stable order)."""
-    return [v for k, v in df if k == key]
-
-def parse_runpath_dirs(elf_path, elf_dynamic_fields):
-    """Parse a RUNPATH entry from an elf header bytestring.
-
-    Returns:
-      { path: unmodified string from DT_RUNPATH
-      , absolute_path: fully normalized, absolute path to dir }
-    """
-    fields = __query_dynamic_fields(elf_dynamic_fields, b"RUNPATH")
-    if fields == []:
-        return []
-    assert len(fields) == 1
-    val = fields[0]
-    origin = os.path.dirname(elf_path)
-    return [{ 'path': path,
-              'absolute_path': os.path.abspath(path.replace("$ORIGIN", origin)) }
-            for path in val.decode().strip(":").split(":")
-            if path != ""]
-
-def parse_needed(elf_dynamic_fields):
-    """Returns the list of DT_NEEDED entries for elf"""
-    return [n.decode() for n in __query_dynamic_fields(elf_dynamic_fields, b"NEEDED")]
-
-
-### Main utility
-
-# cannot find dependency
-LDD_MISSING = "MISSING"
-# don't know how to search for dependency
-LDD_UNKNOWN = "DUNNO"
-# list of all errors for easy branching
-LDD_ERRORS = [ LDD_MISSING, LDD_UNKNOWN ]
-
-def _ldd(elf_cache, f, elf_path):
-    """Same as `ldd` (below), except for an additional `elf_cache` argument,
-    which is a dict needed for memoizing elf files that were already read.
-    This is done because the elf reading operation is quite expensive
-    and many files are referenced multiple times (e.g. glib.so)."""
-
-    def search(rdirs, elf_libname):
-        """search for elf_libname in runfile dirs
-        and return either the name or missing"""
-        res = LDD_MISSING
-        for rdir in rdirs:
-            potential_path = os.path.join(rdir['absolute_path'], elf_libname)
-            if os.path.exists(potential_path):
-                res = {
-                    'item': potential_path,
-                    'found_in': rdir,
-                }
-                break
-        return res
-
-    def recurse(search_res):
-        """Unfold the subtree of ELF dependencies for a `search` result"""
-        if search_res == LDD_MISSING:
-            return LDD_MISSING
-        else:
-            # we keep all other fields in search_res the same,
-            # just item is the one that does the recursion.
-            # This is the part that would normally be done by fmap.
-            search_res['item'] = _ldd(elf_cache, f, search_res['item'])
-            return search_res
-
-    # (GNU) ld.so resolves any symlinks before searching for dependencies
-    elf_realpath = os.path.realpath(elf_path)
-
-    # memoized uses the cache to not repeat the I/O action
-    # for the same elf files (same path)
-    dyn_fields = memoized(
-        elf_cache, read_dynamic_fields, elf_realpath
-    )
-    rdirs = parse_runpath_dirs(elf_realpath, dyn_fields)
-    all_needed = parse_needed(dyn_fields)
-
-    # if there's no runpath dirs we don't know where to search
-    if rdirs == []:
-        needed = list_to_dict(const(LDD_UNKNOWN), all_needed)
-    else:
-        needed = list_to_dict(
-            lambda name: recurse(search(rdirs, name)),
-            all_needed
-        )
-
-    result = {
-        'runpath_dirs': rdirs,
-        'needed': needed
-    }
-    # Here, f is applied to the result of the previous level of recursion
-    return f(result)
-
-
-def ldd(f, elf_path):
-    """follows DT_NEEDED ELF headers for elf by searching the through DT_RUNPATH.
-
-    DependencyInfo :
-    { needed : dict(string, union(
-        LDD_MISSING, LDD_UNKNOWN,
-        {
-            # the needed dependency
-            item : a,
-            # where the dependency was found in
-            found_in : RunpathDir
-        }))
-    # all runpath directories that were searched
-    , runpath_dirs : [ RunpathDir ] }
-
-    Args:
-        f: DependencyInfo -> a
-        modifies the results of each level
-        elf_path: path to ELF file, either absolute or relative to current working dir
-
-    Returns: a
-    """
-    elf_cache = {}
-    return _ldd(elf_cache, f, elf_path)
-
-
-### Functions to pass to ldd
-
-# Only use the current layer
-
-def remove_matching_needed(d, re_matcher_absolute_path=None, re_matcher_path=None):
-    """Destructively removes needed values from d['needed']
-    if they match the given regex matcher.
-    Doesn't remove LDD_ERRORS."""
-    def pred(v):
-        """return true if match"""
-        if v in LDD_ERRORS:
-            return False
-        found_in = v['found_in']
-        abs_match = re_matcher_absolute_path.match(found_in['absolute_path']) \
-                    if re_matcher_absolute_path else False
-        match = re_matcher_path.match(found_in['path']) \
-                    if re_matcher_path else False
-        if abs_match or match:
-            return True
-    d['needed'] = {
-        k: v for k, v in d['needed'].items()
-        if not pred(v)
-    }
-
-def remove_matching_runpaths(d, re_matcher):
-    """Destructively removes runpaths from d['runpath_dirs']
-    if they match the given regex matcher."""
-    d['runpath_dirs'] = [
-        runp for runp in d['runpath_dirs']
-        if not re_matcher.match(runp['absolute_path'])
-    ]
-    return d
-
-def non_existing_runpaths(d):
-    """Return a list of runpaths_dirs that do not exist in the file system."""
-    return [
-        runp for runp in d['runpath_dirs']
-        if not os.path.exists(runp['absolute_path'])
-    ]
-
-def unused_runpaths(d):
-    """Return a list of runpath_dirs that were not used to find NEEDED dependencies."""
-    used = set()
-    for k, v in d['needed'].items():
-        if not v in LDD_ERRORS:
-            used.add(v['found_in']['absolute_path'])
-    return [
-        u for u in d['runpath_dirs']
-        if u['absolute_path'] not in used
-    ]
-
-# Also use the results of sub-layers
-
-def collect_unused_runpaths(d):
-    """This is like `unused_runpaths`, but it creates a deduplicated list of all unused runpaths
-    for its dependencies instead of just returning them for the current layer.
-
-    Returns:
-      a dict of two fields;
-      `mine` contains the unused dependencies of the current binary under scrutiny
-      `others` contains a flat dict of all .sos with unused runpath entries and a list of them for each .so
-    """
-    used = set()
-    given = set(r['absolute_path'] for r in d['runpath_dirs'])
-    prev = {}
-    # TODO: use `unused_runpaths` here
-    for k, v in d['needed'].items():
-        if not v in LDD_ERRORS:
-            used.add(v['found_in']['absolute_path'])
-            prev[k] = v['item']
-    unused = [
-        u for u in given.difference(used)
-        # leave out nix storepaths
-        if not u.startswith("/nix/store")
-    ]
-
-    # Each layer doesn't know about their own name
-    # So we return a list of unused for this layer ('mine')
-    # and a dict of all previeous layers combined (name to list)
-    def combine_unused(deps):
-        res = {}
-        for name, dep in deps.items():
-            res.update(dep['others'])
-            res[name] = dep['mine']
-        return res
-
-    return {
-        'mine': unused,
-        'others': combine_unused(prev),
-    }