Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 292 insertions, 0 deletions

diff --git a/config/check_vanilla_allocations.py b/config/check_vanilla_allocations.py
new file mode 100644
index 0000000000..10bacd4fd3
--- /dev/null
+++ b/config/check_vanilla_allocations.py
@@ -0,0 +1,292 @@
+# vim: set ts=8 sts=4 et sw=4 tw=79:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# ----------------------------------------------------------------------------
+# All heap allocations in SpiderMonkey must go through js_malloc, js_calloc,
+# js_realloc, and js_free.  This is so that any embedder who uses a custom
+# allocator (by defining JS_USE_CUSTOM_ALLOCATOR) will see all heap allocation
+# go through that custom allocator.
+#
+# Therefore, the presence of any calls to "vanilla" allocation/free functions
+# from within SpiderMonkey itself (e.g. malloc(), free()) is a bug.  Calls from
+# within mozglue and non-SpiderMonkey locations are fine; there is a list of
+# exceptions that can be added to as the need arises.
+#
+# This script checks for the presence of such disallowed vanilla
+# allocation/free function in SpiderMonkey when it's built as a library.  It
+# relies on |nm| from the GNU binutils, and so only works on Linux, but one
+# platform is good enough to catch almost all violations.
+#
+# This checking is only 100% reliable in a JS_USE_CUSTOM_ALLOCATOR build in
+# which the default definitions of js_malloc et al (in Utility.h) -- which call
+# malloc et al -- are replaced with empty definitions.  This is because the
+# presence and possible inlining of the default js_malloc et al can cause
+# malloc/calloc/realloc/free calls show up in unpredictable places.
+#
+# Unfortunately, that configuration cannot be tested on Mozilla's standard
+# testing infrastructure.  Instead, by default this script only tests that none
+# of the other vanilla allocation/free functions (operator new, memalign, etc)
+# are present.  If given the --aggressive flag, it will also check for
+# malloc/calloc/realloc/free.
+#
+# Note:  We don't check for |operator delete| and |operator delete[]|.  These
+# can be present somehow due to virtual destructors, but this is not too
+# because vanilla delete/delete[] calls don't make sense without corresponding
+# vanilla new/new[] calls, and any explicit calls will be caught by Valgrind's
+# mismatched alloc/free checking.
+# ----------------------------------------------------------------------------
+
+import argparse
+import re
+import subprocess
+import sys
+from collections import defaultdict
+
+import buildconfig
+
+# The obvious way to implement this script is to search for occurrences of
+# malloc et al, succeed if none are found, and fail is some are found.
+# However, "none are found" does not necessarily mean "none are present" --
+# this script could be buggy.  (Or the output format of |nm| might change in
+# the future.)
+#
+# So util/Utility.cpp deliberately contains a (never-called) function that
+# contains a single use of all the vanilla allocation/free functions.  And this
+# script fails if it (a) finds uses of those functions in files other than
+# util/Utility.cpp, *or* (b) fails to find them in util/Utility.cpp.
+
+# Tracks overall success of the test.
+has_failed = False
+
+
+def fail(msg):
+    print("TEST-UNEXPECTED-FAIL | check_vanilla_allocations.py |", msg)
+    global has_failed
+    has_failed = True
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--aggressive",
+        action="store_true",
+        help="also check for malloc, calloc, realloc and free",
+    )
+    parser.add_argument("file", type=str, help="name of the file to check")
+    args = parser.parse_args()
+
+    # Run |nm|.  Options:
+    # -C: demangle symbol names
+    # -A: show an object filename for each undefined symbol
+    nm = buildconfig.substs.get("NM") or "nm"
+    cmd = [nm, "-C", "-A", args.file]
+    lines = subprocess.check_output(
+        cmd, universal_newlines=True, stderr=subprocess.PIPE
+    ).split("\n")
+
+    # alloc_fns contains all the vanilla allocation/free functions that we look
+    # for. Regexp chars are escaped appropriately.
+
+    operator_news = [
+        # Matches |operator new(unsigned T)|, where |T| is |int| or |long|.
+        r"operator new(unsigned",
+        # Matches |operator new[](unsigned T)|, where |T| is |int| or |long|.
+        r"operator new[](unsigned",
+    ]
+
+    # operator new may end up inlined and replaced with moz_xmalloc.
+    inlined_operator_news = [
+        r"moz_xmalloc",
+    ]
+
+    alloc_fns = (
+        operator_news
+        + inlined_operator_news
+        + [
+            r"memalign",
+            # These three aren't available on all Linux configurations.
+            # r'posix_memalign',
+            # r'aligned_alloc',
+            # r'valloc',
+        ]
+    )
+
+    if args.aggressive:
+        alloc_fns += [r"malloc", r"calloc", r"realloc", r"free", r"strdup"]
+
+    # This is like alloc_fns, but regexp chars are not escaped.
+    alloc_fns_escaped = [re.escape(fn) for fn in alloc_fns]
+
+    # This regexp matches the relevant lines in the output of |nm|, which look
+    # like the following.
+    #
+    #   js/src/libjs_static.a:Utility.o:                  U malloc
+    #   js/src/libjs_static.a:Utility.o: 00000000000007e0 T js::SetSourceOptions(...)
+    #
+    # It may also, in LTO builds, look like
+    #   js/src/libjs_static.a:Utility.o: ---------------- T js::SetSourceOptions(...)
+    #
+    nm_line_re = re.compile(r"([^:/ ]+):\s*(?:[0-9a-fA-F]*|-*)\s+([TUw]) (.*)")
+    alloc_fns_re = re.compile(r"|".join(alloc_fns_escaped))
+
+    # This tracks which allocation/free functions have been seen.
+    functions = defaultdict(set)
+    files = defaultdict(int)
+
+    # Files to ignore allocation/free functions from.
+    ignored_files = [
+        # Ignore implicit call to operator new in std::condition_variable_any.
+        #
+        # From intl/icu/source/common/umutex.h:
+        # On Linux, the default constructor of std::condition_variable_any
+        # produces an in-line reference to global operator new(), [...].
+        "umutex.o",
+        # Ignore allocations from decimal conversion functions inside mozglue.
+        "Decimal.o",
+        # Ignore use of std::string in regexp AST debug output.
+        "regexp-ast.o",
+    ]
+    all_ignored_files = set((f, 1) for f in ignored_files)
+
+    # Would it be helpful to emit detailed line number information after a failure?
+    emit_line_info = False
+
+    prev_filename = None
+    for line in lines:
+        m = nm_line_re.search(line)
+        if m is None:
+            continue
+
+        filename, symtype, fn = m.groups()
+        if prev_filename != filename:
+            # When the same filename appears multiple times, separated by other
+            # file names, this denotes a different file. Thankfully, we can more
+            # or less safely assume that dir1/Foo.o and dir2/Foo.o are not going
+            # to be next to each other.
+            files[filename] += 1
+            prev_filename = filename
+
+        # The stdc++compat library has an implicit call to operator new in
+        # thread::_M_start_thread.
+        if "stdc++compat" in filename:
+            continue
+
+        # The memory allocator code contains calls to memalign. These are ok, so
+        # we whitelist them.
+        if "_memory_" in filename:
+            continue
+
+        # Ignore the fuzzing code imported from m-c
+        if "Fuzzer" in filename:
+            continue
+
+        # Ignore the profiling pseudo-stack, since it needs to run even when
+        # SpiderMonkey's allocator isn't initialized.
+        if "ProfilingStack" in filename:
+            continue
+
+        if symtype == "T":
+            # We can't match intl/components files by file name because in
+            # non-unified builds they overlap with files in js/src.
+            # So we check symbols they define, and consider files with symbols
+            # in the mozilla::intl namespace to be those.
+            if fn.startswith("mozilla::intl::"):
+                all_ignored_files.add((filename, files[filename]))
+        else:
+            m = alloc_fns_re.match(fn)
+            if m:
+                functions[(filename, files[filename])].add(m.group(0))
+
+    util_Utility_cpp = functions.pop(("Utility.o", 1))
+    if ("Utility.o", 2) in functions:
+        fail("There should be only one Utility.o file")
+
+    for f, n in all_ignored_files:
+        functions.pop((f, n), None)
+        if f in ignored_files and (f, 2) in functions:
+            fail(f"There should be only one {f} file")
+
+    for (filename, n) in sorted(functions):
+        for fn in functions[(filename, n)]:
+            # An allocation is present in a non-special file.  Fail!
+            fail("'" + fn + "' present in " + filename)
+            # Try to give more precise information about the offending code.
+            emit_line_info = True
+
+    # Check that all functions we expect are used in util/Utility.cpp.  (This
+    # will fail if the function-detection code breaks at any point.)
+    # operator new and its inlined equivalent are mutually exclusive.
+    has_operator_news = any(fn in operator_news for fn in util_Utility_cpp)
+    has_inlined_operator_news = any(
+        fn in inlined_operator_news for fn in util_Utility_cpp
+    )
+    if has_operator_news and has_inlined_operator_news:
+        fail(
+            "Both operator new and moz_xmalloc aren't expected in util/Utility.cpp at the same time"
+        )
+
+    for fn in alloc_fns:
+        if fn not in util_Utility_cpp:
+            if (
+                (fn in operator_news and not has_inlined_operator_news)
+                or (fn in inlined_operator_news and not has_operator_news)
+                or (fn not in operator_news and fn not in inlined_operator_news)
+            ):
+                fail("'" + fn + "' isn't used as expected in util/Utility.cpp")
+        else:
+            util_Utility_cpp.remove(fn)
+
+    # This should never happen, but check just in case.
+    if util_Utility_cpp:
+        fail(
+            "unexpected allocation fns used in util/Utility.cpp: "
+            + ", ".join(util_Utility_cpp)
+        )
+
+    # If we found any improper references to allocation functions, try to use
+    # DWARF debug info to get more accurate line number information about the
+    # bad calls. This is a lot slower than 'nm -A', and it is not always
+    # precise when building with --enable-optimized.
+    if emit_line_info:
+        print("check_vanilla_allocations.py: Source lines with allocation calls:")
+        print(
+            "check_vanilla_allocations.py: Accurate in unoptimized builds; "
+            "util/Utility.cpp expected."
+        )
+
+        # Run |nm|.  Options:
+        # -u: show only undefined symbols
+        # -C: demangle symbol names
+        # -l: show line number information for each undefined symbol
+        cmd = ["nm", "-u", "-C", "-l", args.file]
+        lines = subprocess.check_output(
+            cmd, universal_newlines=True, stderr=subprocess.PIPE
+        ).split("\n")
+
+        # This regexp matches the relevant lines in the output of |nm -l|,
+        # which look like the following.
+        #
+        #       U malloc util/Utility.cpp:117
+        #
+        alloc_lines_re = (
+            r"[Uw] ((" + r"|".join(alloc_fns_escaped) + r").*)\s+(\S+:\d+)$"
+        )
+
+        for line in lines:
+            m = re.search(alloc_lines_re, line)
+            if m:
+                print(
+                    "check_vanilla_allocations.py:", m.group(1), "called at", m.group(3)
+                )
+
+    if has_failed:
+        sys.exit(1)
+
+    print("TEST-PASS | check_vanilla_allocations.py | ok")
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()