dlang-community / std_data_json

Phobos candidate JSON implementation.
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Possibly-related memory corruption issue #43

Open Abscissa opened 5 years ago

Abscissa commented 5 years ago

I guessing this is probably a dmd issue, and filed it as 19825. But I'm posting here too, just in case std_data_json is part of the problem, or anyone here could help find the exact compiler problem:

dub.sdl:

name "test"
dependency "std_data_json" version="==0.18.3"

main.d:

import std.stdio;
import stdx.data.json;

enum rawJson = `
{
    "rootPackage": "vibe-d",
    "targets": [
        {
            "rootConfiguration": "vibe-core"
        }
    ]
}
`;

void yap(T...)(lazy T args)
{
    writeln(args);
}

struct Foo
{
    int a;
    string name;
}

Foo makeFoo()
{
    Foo foo;

    auto root = rawJson.toJSONValue;
    foo.name = root["rootPackage"].toString.idup;
    writeln(foo.name);
    yap(root["targets"][0]["rootConfiguration"]);

    return foo;
}

void main(string[] args)
{
    auto foo = makeFoo();
    writeln(foo.name); // Garbled output, then an exception
}

result:

$ dub -q
vibe-d
vibe-core
[...garbled data here...]uncaught exception
std.exception.ErrnoException@/home/nick/.dvm/compilers/dmd-2.085.0/linux/bin/../../src/phobos/std/stdio.d(2882): Enforcement failed (Bad address)
----------------
/home/nick/.dvm/compilers/dmd-2.085.0/linux/bin/../../src/phobos/std/exception.d:515 @safe void std.exception.bailOut!(std.exception.ErrnoException).bailOut(immutable(char)[], ulong, scope const(char)[]) [0xf11be9a1]
/home/nick/.dvm/compilers/dmd-2.085.0/linux/bin/../../src/phobos/std/exception.d:436 @safe int std.exception.enforce!(std.exception.ErrnoException).enforce!(int).enforce(int, lazy const(char)[], immutable(char)[], ulong) [0xf11be921]
/home/nick/.dvm/compilers/dmd-2.085.0/linux/bin/../../src/phobos/std/stdio.d:2882 @safe void std.stdio.File.LockingTextWriter.put!(immutable(char)[]).put(scope immutable(char)[]) [0xf11be81f]
/home/nick/.dvm/compilers/dmd-2.085.0/linux/bin/../../src/phobos/std/stdio.d:3806 @safe void std.stdio.writeln!(immutable(char)[]).writeln(immutable(char)[]) [0xf11be747]
src/main.d:41 _Dmain [0xf11a69d8]
Program exited with code -6
s-ludwig commented 5 years ago

It's not clear from the code, but it might be caused by https://github.com/s-ludwig/taggedalgebraic/pull/29 - did you build with the latest 0.11.4 release?

Abscissa commented 5 years ago

Hmm, it appears to be pulling in 0.10.13, not 0.11.4. Apparently the latest release of std_data_json (0.18.3) has its taggedalgebraic dependency set to ~>0.10.1. I tried manually editing dub.selections.json to 0.11.4, and I'm still getting the same issue, but I don't know whether dub might be just simply ignoring the 0.11.4 setting since it conflicts with the dependency constraints.

FeepingCreature commented 5 years ago

Cannot reproduce here. Your dub.sdl is not enough to produce a working binary with dub 1.15.0/dmd 2.087.1. When I filled in the missing values, I did not get a crash. Is this still an issue?