Since commit 9452a8dfa3, the new debug info format is only generated
for LLVM 8 and newer versions. However, the tests still assume that LLVM
7 will use the new debug info format. Fix the tests (and a comment in
the code) to match the actual version check.
Bug #52452 notes some debuginfo test regressions when moving to gdb
8.1. This series will also cause versions of gdb before 8.2 to fail
when a recent LLVM is used -- DW_TAG_variant_part support was not
added until 8.2.
This patch updates one of the builders to a later version of Ubuntu,
which comes with gdb 8.2. It updates the relevant tests to require
both a new-enough LLVM and a new-enough gdb; the subsequent patch
arranges to continue testing the fallback mode.
The "gdbg" results are removed from these tests because the tests now
require a rust-enabled gdb.
If you read closely, you'll see that some of the lldb results in this
patch still look a bit strange. This will be addressed in a
subsequent patch; I believe the fix is to disable the Python
pretty-printers when lldb is rust-enabled.
If the rust-enabled lldb was built, then use it when running the
debuginfo tests. Updating the lldb submodule was necessary as this
needed a way to differentiate the rust-enabled lldb, so I added a line
to the --version output.
This adds compiletest commands to differentiate between the
rust-enabled and non-rust-enabled lldb, as is already done for gdb. A
new "rust-lldb" header directive is also added, but not used in this
patch; I plan to use it in #54004.
This updates all the tests.
This is the kind of change that one is expected to need to make to
accommodate overloaded-`box`.
----
Note that this is not *all* of the changes necessary to accommodate
Issue 22181. It is merely the subset of those cases where there was
already a let-binding in place that made it easy to add the necesasry
type ascription.
(For unnamed intermediate `Box` values, one must go down a different
route; `Box::new` is the option that maximizes portability, but has
potential inefficiency depending on whether the call is inlined.)
----
There is one place worth note, `run-pass/coerce-match.rs`, where I
used an ugly form of `Box<_>` type ascription where I would have
preferred to use `Box::new` to accommodate overloaded-`box`. I
deliberately did not use `Box::new` here, because that is already done
in coerce-match-calls.rs.
----
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
LLDB doesn't allow for reading 'artifical' fields (fields that are generated by the compiler). So do not mark, slice fields, enum discriminants, and GcBox value fields as artificial.
So far the DWARF information for enums was different
for regular enums, univariant enums, Option-like enums,
etc. Regular enums were encoded as unions of structs,
while the other variants were encoded as bare structs.
With the changes in this PR all enums are encoded as
unions so that debuggers can reconstruct if something
originally was a struct, a univariant enum, or an
Option-like enum. For the latter case, information
about the Null variant is encoded into the union field
name. This information can then be used by the
debugger to print a None value actually as None
instead of Some(0x0).
