invalid memory read in gc

[ghost]

Compiling an empty D2 program (void main() {}) using ldc2 master (ldc b41688a, druntime v2.054-226-g10e4512 and phobos v2.054-844-g1f6264e) and then running it through valgrind gives me an invalid read, conditional jump depending on uninit value and 5 leaks. (for details: http://pastebin.com/sEfnqUdd).

Compiling the same program with the dmd 2.057 from d-p-l.org and running it through valgrind gives no invalid read or conditional jump depending on uninit value and only 4 memory leaks, which are included in the 5 from ldc2. The one which happens only if using ldc2 is #2.

line 2280 in gcx.d (which is the offending line) contains the following code:
auto p = cast(byte _)(_p1);

and the conditional jump depending on uninit value is most probably just a subsequent error which will go away when the invalid read is solved.

pompei2: Looks like one of the GC root ranges our druntime uses is off, thus producing an invalid read. Don't know off-hand if this is a bug, though [...]

[redstar]

I checked some programs with release-0.15.0. There are no invalid memory reads but still conditional jumps depending on uninit value. But dmd 2.066.1 also has conditional jumps depending on uninit value. Looks like the invalid memory read is solved and the rest depends on upstream fixes.

[dnadlinger]

Jumps depending on uninitialized values are expected to happen within a non-precise GC.