Type annotations for instruction operands are omitted, e.g.
```
%3 = struct $S(%1, %2)
```
Operand types are redundant anyway and were only used for sanity checking in the SIL parser.
But: operand types _are_ printed if the definition of the operand value was not printed yet.
This happens:
* if the block with the definition appears after the block where the operand's instruction is located
* if a block or instruction is printed in isolation, e.g. in a debugger
The old behavior can be restored with `-Xllvm -sil-print-types`.
This option is added to many existing test files which check for operand types in their check-lines.
Based on https://github.com/apple/swift/pull/66409
With the observation that the pre-opaque world was using bitcast as an
indication that the storage type and the type of the variable were
different. We can recover this information from the storage type of the
alloca and the storage type of the type info.
This patch replace all in-memory objects of DebugValueAddrInst with
DebugValueInst + op_deref, and duplicates logics that handles
DebugValueAddrInst with the latter. All related check in the tests
have been updated as well.
Note that this patch neither remove the DebugValueAddrInst class nor
remove `debug_value_addr` syntax in the test inputs.
We were using compiler-generated source location (i.e. line number
0) on `debug_value` instructions were emitted by salvage debug info.
But it turned out that IRGen will attach DW_AT_artificial on the
associated debug variables, which are hidden in debugger by default.
This patch prevent this issue by using the source location from the
just-deleted instruction for these `debug_value` instructions.
This indirectly triggered another bug where some of the LLVM
!DIExpression-s we generated are actually invalid -- more specifically,
the fragment inside is covering the whole debug variable. The reason it was
not previously caught is because LLVM verifier skips any debug variable
that is marked artificial, and all debug variables that have illegal fragment
are falling under this category. Thus, this patch also fixes this issue
by not generating the DW_OP_LLVM_fragment part if it's illegal.
This patch is primarily doing two things:
- Teach IRGen for some of the instructions to generate debug info based
on SILDebugVariable rather than AST node, which is not always
available when reading from SIL.
- Generate corresponding `llvm.dbg.*` intrinsics and `!DIExpression`
from the newly added SIL DIExpression.
Currently the debug info infrastructure inside SIL can only associate a
source variable with a single (simple) SSA value. Which is insufficient
to preserve (correct) debug info across SIL-level optimizations -- for
example, SROA that decompose or even eliminate aggregate-type obejcts.
By adding DIExpression into SIL, we are able to reconstruct the
connection between a source variable and its SSA value counterpart, even
across optimizations. This patch adds such support into in-memory
representation for SIL instructions and the SILParser/Printer. The
following patch will add changes for the IRGen part.
