This should have no effect for header only libraries as mentioned.
It was previously removed in e509007d but then accidentally added
again in 26cfec34.
Signed-off-by: Jeremy Nimmer <jeremy.nimmer@tri.global>
* Hash deeply nested values without recursing per nesting level
std::hash<basic_json> hashed an array or object by hashing each element,
which called detail::hash again once per nesting level. A value nested
deeply enough - 50,000 levels of objects on an 8 MiB stack - exhausted
the call stack and terminated the process. parse() accepts such values
without complaint, since the parser is iterative, and a parsed value is
hashed wherever it is used as a key in an unordered container.
Bound the descent the same way dump() does: detail::hash takes the
nesting level, and once hash_depth_limit() (128) levels have been entered,
hash_iteratively() hashes what is left on an explicit stack. It combines
the seeds in exactly the same order, so hash values are unchanged. A value
nested less deeply than the bound is hashed by the same code as before,
without allocating, and is as fast as before.
Tests check that every depth up to twice the bound hashes exactly like
the recursive definition of the hash, and that values nested 100,000
levels deep hash without crashing.
Fixes#5545 for std::hash.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Declare hash_frame's constructor noexcept
GCC's -Wnoexcept (an error in CI) flags the emplace_back() into the
hash stack under C++26: the constructor cannot throw, since cbegin() is
noexcept, but it did not say so. dump_frame's constructor is noexcept
for the same reason.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Share one recursion depth limit, and copy the hash frame out of the stack
dump() and hash() each defined their own limit on how many nesting levels
they recurse into, and the operations still to come would have added more,
free to diverge over time. They now all use detail::recursion_depth_limit(),
in a header of its own; serializer::dump_depth_limit() and
hash_depth_limit() are gone.
hash_iteratively() now copies the frame it works on out of the stack and
changes the frame only through stack.back(), so nothing can refer into
the stack after entering an element has grown it.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Parenthesize multiplications in the hash test for clang-tidy
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Add missing headers to BUILD.bazel and make its generator reproduce it
The "json" cc_library did not list three headers that the library
includes:
- detail/meta/logic.hpp (added in #5016, included by from_json.hpp)
- detail/input/number_parse.hpp (added in #5283, included by lexer.hpp)
- detail/input/string_scan.hpp (added in #5283, included by lexer.hpp
and serializer.hpp)
Bazel's sandbox only exposes declared headers, so any target depending
on @nlohmann_json//:json and including <nlohmann/json.hpp> failed with
"'nlohmann/detail/meta/logic.hpp' file not found".
The file could not simply be regenerated, because the generator behind
"make BUILD.bazel" was stale: it wrote only the "json" cc_library and
dropped the load() statements, the license block, and the
"singleheader-json" target that were added by hand in #4584. The
generator now emits the complete file, so its output differs from the
previous BUILD.bazel only by the three headers. It also resolves the
glob against the project root instead of the working directory and
sorts the list explicitly.
"make BUILD.bazel" is now phony: in a fresh checkout, BUILD.bazel is
not older than the headers, so make considered it up to date, and a
removed header would never trigger a rebuild. "make check-amalgamation"
also checks that BUILD.bazel is up to date.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Check in CI that BUILD.bazel is up to date
The "Check amalgamation" workflow now also regenerates BUILD.bazel, so a
pull request that adds, renames, or removes a header without updating
the Bazel header list fails, and the attached amalgamation.patch
contains the fix. The failure comment and the contribution guidelines
mention the new check, and the comment now links to the existing
"Amalgamate the source code" section instead of the "Files to change"
anchor that was removed in #4560.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---------
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Jeremy Nimmer
Niels Lohmann
Vertexwahn
Marcel