Start treating function calls as initializing expressions instead of as
value expressions.
This required adding support for expression categories. Value bindings
and temporary materialization conversions are created where necessary to
transition between expression categories. For a function call with a
return slot, we speculatively create a materialized temporary before the
call and either commit to it or replace it with something else later,
once we see how the function call expression is actually used.
This change follows the direction suggested in #3133 for initializing
expressions: depending on the return type of a function, the return
value will either be initialized in-place or returned directly. This is
visible in the semantics IR, which is a little unfortunate but is
probably necessary as this is part of the semantics of the program.
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Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
This removes BindName, putting name information directly on VarStorage.
As a side-effect of updating semantics_ir_test for this change, I also
noted that function bodies were being generated as invalid YAML so am
fixing that (just `{}` to `[]` bracketing, otherwise the test wouldn't
work anymore).
Because names are now available, I've updated lowering to use them for
vars.
In the SemIR formatter, the name is now repeated because it's a
parameter to VarStorage. I believe this is just default behavior, and
we'd have to special-case VarStorage to remove it because it's automatic
argument printing in action. On the balance, it felt like letting it
print was reasonable.
I've noted in places that the name on VarStorage is expected to be
optional, but am not adding support because I'd have no way of testing
it at present.
Add a textual IR format to the toolchain.
The exact details of the format are somewhat arbitrary right now, and I
expect them to change as we refine the semantics IR model, but at the
moment they're somewhat directly following the current structure of the
IR.
Semantics tests currently test both the "raw" format, which shows the
details of the representation, and the textual format, which is somewhat
higher level. We may want to revisit that decision once the textual
format is a bit more stable, and test only the textual format in most of
these tests, but for now it seems prudent to keep both sets of tests.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Refactor type canonicalization so that we can reuse the same code for
building a `T*` expression and for forming the type of an `&x`
expression.
Add basic computation of expression category in order to check that we
only take the address of durable reference expressions. This is
currently computed on demand rather than being tracked as part of the
semantics node, but in most cases can be determined by looking at only a
single expression, so caching it in the node doesn't seem worthwhile
yet. This decision should be revisited if we start doing more complex
category calculations.
Also add trivial lowering support, but it doesn't work properly yet
because lowering doesn't yet take the expression category into account.
Allow interleaving of STDOUT and STDERR check lines. Put STDOUT lines
after the line they're attached to, and STDERR lines before. If no
STDOUT check line is attached to any line, then put them all at the end
of the file instead.
This is intended to better handle the case where stdout contains
unreplaced mentions of line numbers, and also reflects that stdout is
typically a consequence of the test rather than commentary on it, so
placing it after the test seems likely to read better.
Semantic handling for use of `T*` and `const T` as types.
There's no way to form values of these types yet, and no conversions for
them are supported.
Factor out the common code to canonicalize types using a folding set,
and switch to using the same folding set for all kinds of type by adding
the kind as part of the folding set key.
Improve type printing to not include the `as type` portion when the type
is printed in a context within another type where a conversion to `type`
is implied, as in `{}*` and pre-existing cases like `({}, {}) as type`
(which we used to print as `({} as type, {} as type}) as type`.
Richard SmithandChandler Carruth
Jon Ross-Perkins