This is a follow-up to #132129.
Currently, only `Parser` and `SemaBase` get a `DiagCompat()` helper; I’m
planning to keep refactoring compatibility warnings and add more helpers
to other classes as needed. I also refactored a single parser compat
warning just to make sure everything works properly when diagnostics
across multiple components (i.e. Sema and Parser in this case) are
involved.
The 'declare' construct is the first of two 'declaration' level
constructs, so it is legal in any place a declaration is, including as a
statement, which this accomplishes by wrapping it in a DeclStmt. All
clauses on this have a 'same scope' requirement, which this enforces as
declaration context instead, which makes it possible to implement these
as a template.
The 'link' and 'device_resident' clauses are also added, which have some
similar/small restrictions, but are otherwise pretty rote.
This patch implements all of the above.
Resolves: #70930 (and probably latest comments from clangd/clangd#251)
by fixing racing for the shared DiagStorage value which caused messing with args inside the storage and then formatting the following message with getArgSInt(1) == 2:
def err_module_odr_violation_function : Error<
"%q0 has different definitions in different modules; "
"%select{definition in module '%2'|defined here}1 "
"first difference is "
which causes HandleSelectModifier to go beyond the ArgumentLen so the recursive call to FormatDiagnostic was made with DiagStr > DiagEnd that leads to infinite while (DiagStr != DiagEnd).
The Main Idea:
Reuse the existing DiagStorageAllocator logic to make all DiagnosticBuilders having independent states.
Also, encapsulating the rest of state (e.g. ID and Loc) into DiagnosticBuilder.
The last attempt failed -
https://github.com/llvm/llvm-project/pull/108187#issuecomment-2353122096
so was reverted - #108838
Resolves: #70930 (and probably latest comments from
https://github.com/clangd/clangd/issues/251)
by fixing racing for the shared `DiagStorage` value which caused messing
with args inside the storage and then formatting the following message
with `getArgSInt(1)` == 2:
```
def err_module_odr_violation_function : Error<
"%q0 has different definitions in different modules; "
"%select{definition in module '%2'|defined here}1 "
"first difference is "
```
which causes `HandleSelectModifier` to go beyond the `ArgumentLen` so
the recursive call to `FormatDiagnostic` was made with `DiagStr` >
`DiagEnd` that leads to infinite `while (DiagStr != DiagEnd)`.
**The Main Idea:**
Reuse the existing `DiagStorageAllocator` logic to make all
`DiagnosticBuilder`s having independent states.
Also, encapsulating the rest of state (e.g. ID and Loc) into
`DiagnosticBuilder`.
**TODO (if it will be requested by reviewer):**
- [x] add a test (I have no idea how to turn a whole bunch of my
proprietary code which leads `clangd` to OOM into a small public
example.. probably I must try using
[this](https://github.com/llvm/llvm-project/issues/70930#issuecomment-2209872975)
instead)
- [x] [`Diag.CurDiagID !=
diag::fatal_too_many_errors`](https://github.com/llvm/llvm-project/pull/108187#pullrequestreview-2296395489)
- [ ] ? get rid of `DiagStorageAllocator` at all and make
`DiagnosticBuilder` having they own `DiagnosticStorage` coz it seems
pretty small so should fit the stack for short-living
`DiagnosticBuilder` instances
This is a follow-up to #84184. Multiple reviewers there pointed out to
me that we should have a common base class for `Sema` and `SemaOpenACC`
to avoid code duplication for common helpers like `getLangOpts()`. On
top of that, `Diag()` function was requested for `SemaOpenACC`. This
patch delivers both.
The intent is to keep `SemaBase` as small as possible, as things there
are globally available across `Sema` and its parts without any
additional effort from usage side. Overused, this can undermine the
whole endeavor of splitting `Sema` apart.
Apart of shuffling code around, this patch introduces a helper private
function `SemaDiagnosticBuilder::getDeviceDeferredDiags()`, the sole
purpose of which is to encapsulate member access into (incomplete)
`Sema` for function templates defined in the header, where `Sema` can't
be complete.
