LLVM assertion when creating region pointer for bare self value #5280

jdm · 2013-03-08T04:57:52Z

type FontTableTag = u32;

trait FontTableTagConversions {
  fn tag_to_str(self);
}

impl FontTableTagConversions for FontTableTag {
  fn tag_to_str(self) {
    &self;
  }
}

fn main() {
    5.tag_to_str();
}

rustc: /run/media/jdm/ssd/rust/src/llvm/lib/VMCore/Instructions.cpp:2383: static llvm::CastInst* llvm::CastInst::CreatePointerCast(llvm::Value*, llvm::Type*, const llvm::Twine&, llvm::Instruction*): Assertion S->getType()->isPointerTy() && "Invalid cast"' failed.`

The text was updated successfully, but these errors were encountered:

graydon · 2013-04-30T22:13:59Z

assigning bug; change assignment if you disagree

catamorphism · 2013-06-26T19:35:44Z

Reproduced with efd1438

Blei · 2013-06-28T19:41:45Z

This seems to be fixed on 887ae82 (linux 64).

Currently we pass all "self" arguments by reference, for the pointer variants this means that we end up with double indirection which causes a unnecessary performance hit. The fix itself is pretty straight-forward and just means that "self" needs to be handled like any other argument, except for by-value "self" which still needs to be passed by reference. This is because non-pointer types can't just be stuffed into the environment slot which is used to pass "self". What made things tricky is that there was also a bug in the typechecker where the method map entries are created. For type impls, that stored the base type instead of the actual self-type in the method map, e.g. Foo instead of &Foo for &self. That worked with pass-by-reference, but fails with pass-by-value which needs the real type. Code that makes use of methods seems to be about 10% faster with this change. Also, build times are reduced by about 4%. Fixes rust-lang#4355, rust-lang#4402, rust-lang#5280, rust-lang#4406 and rust-lang#7285

Currently we pass all "self" arguments by reference, for the pointer variants this means that we end up with double indirection which causes a unnecessary performance hit. The fix itself is pretty straight-forward and just means that "self" needs to be handled like any other argument, except for by-value "self" which still needs to be passed by reference. This is because non-pointer types can't just be stuffed into the environment slot which is used to pass "self". What made things tricky is that there was also a bug in the typechecker where the method map entries are created. For type impls, that stored the base type instead of the actual self-type in the method map, e.g. Foo instead of &Foo for &self. That worked with pass-by-reference, but fails with pass-by-value which needs the real type. Code that makes use of methods seems to be about 10% faster with this change. Also, build times are reduced by about 4%. Fixes #4355, #4402, #5280, #4406 and #7285

…ip1995,Manishearth needless_doc_main: only check rust code This fixes rust-lang#5280 by checking the language attribute on code blocks. --- changelog: none

ghost assigned nikomatsakis Apr 30, 2013

dotdash mentioned this issue Jun 28, 2013

Avoid double indirection for the "self" arg in methods #7452

Merged

luqmana closed this as completed Jun 28, 2013

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Uh oh!

LLVM assertion when creating region pointer for bare self value #5280

LLVM assertion when creating region pointer for bare self value #5280

jdm commented Mar 8, 2013

graydon commented Apr 30, 2013

Uh oh!

catamorphism commented Jun 26, 2013

Uh oh!

Blei commented Jun 28, 2013

Uh oh!

LLVM assertion when creating region pointer for bare self value #5280

LLVM assertion when creating region pointer for bare self value #5280

Comments

jdm commented Mar 8, 2013

graydon commented Apr 30, 2013

Uh oh!

catamorphism commented Jun 26, 2013

Uh oh!

Blei commented Jun 28, 2013

Uh oh!