At the moment, bitcode files with invalid forward reference can easily
cause the bitcode reader to run out of memory, by creating a forward
reference with a very high index.
We can use the size of the bitcode file as an upper bound, because a
valid bitcode file can never contain more records. This should be
sufficient to fail early in most cases. The only exception is large
files with invalid forward references close to the file size.
There are a couple of clusterfuzz runs that fail with out-of-memory
because of very high forward references and they should be fixed by this
patch.
A concrete example for this is D64507, which causes out-of-memory on
systems with low memory, like the hexagon upstream bots.
Reviewers: t.p.northover, thegameg, jfb, efriedma, hfinkel
Reviewed By: jfb
Differential Revision: https://reviews.llvm.org/D64577
llvm-svn: 366017
Since r199356, we've printed a warning when dropping debug info.
r225562 started crashing on that, since it registered a diagnostic
handler that only expected errors. This fixes the handler to expect
other severities. As a side effect, it now prints "error: " at the
start of error messages, similar to `llvm-as`.
There was a testcase for r199356, but it only really checked the
assembler. Move `test/Bitcode/drop-debug-info.ll` to `test/Assembler`,
and introduce `test/Bitcode/drop-debug-info.3.5.ll` (and companion
`.bc`) to test the bitcode reader.
Note: tools/gold/gold-plugin.cpp has an equivalent bug, but I'm not sure
what the best fix is there. I'll file a PR.
llvm-svn: 230416
Florian Hahn