The previous code made the assumption that the ASTScope for a variable
declaration should be the one of the declaration's source location. That is not
necessarily the case, in some cases it should be an ancestor scope. This patch
introduces a map from ValueDecl -> ASTScope that is derived from querying each
ASTScope for its locals, which matches also what happens in name lookup. This
patch also fixes the nesting of SILDebugScopes created for guard statement
bodies, which are incorrectly nested in the ASTScope hierarchy.
rdar://108940570
This patch replaces the stateful generation of SILScope information in
SILGenFunction with data derived from the ASTScope hierarchy, which should be
100% in sync with the scopes needed for local variables. The goal is to
eliminate the surprising effects that the stack of cleanup operations can have
on the current state of SILBuilder leading to a fully deterministic (in the
sense of: predictible by a human) association of SILDebugScopes with
SILInstructions. The patch also eliminates the need to many workarounds. There
are still some accomodations for several Sema transformation passes such as
ResultBuilders, which don't correctly update the source locations when moving
around nodes. If these were implemented as macros, this problem would disappear.
This necessary rewrite of the macro scope handling included in this patch also
adds proper support nested macro expansions.
This fixes
rdar://88274783
and either fixes or at least partially addresses the following:
rdar://89252827
rdar://105186946
rdar://105757810
rdar://105997826
rdar://105102288
The debugger relies on function arguments and local variables to be in different
scopes in order to disambiguate between local variables that shadow function
arguments.
rdar://83769198
Before this patch every Swift function would contain a top-level
DW_TAG_lexical_scope that didn't provide any useful information, used extra
space in the debug info and prevented local variables from showing up in virtual
async backtraces.
I am going to be using in inst-simplify/sil-combine/canonicalize instruction a
RAUW everything against everything API (*). This creates some extra ARC
traffic/borrows. It is going to be useful to have some simple peepholes that
gets rid of some of the extraneous traffic.
(*) Noting that we are not going to support replacing non-trivial
OwnershipKind::None values with non-trivial OwnershipKind::* values. This is a
corner case that only comes up with non-trivial enums that have a non-payloaded
or trivial enum case. It is much more complex to implement that transform, but
it is an edge case, so we are just not going to support those for now.
----
I also eliminated the dependence of SILGenCleanup on Swift/SwiftShims. This
speeds up iterating on the test case with a debug compiler since we don't need
those modules.
For context, String, Nil, and Bool already behave this way.
Note: Before it used to construct (call, ... (integer_literal)), and the
call would be made explicit / implicit based on if you did eg: Int(3) or
just 3. This however did not translate to the new world so this PR adds
a IsExplicitConversion bit to NumberLiteralExpr. Some side results of
all this are that some warnings changed a little and some instructions are
emitted in a different order.
This does not eliminate the entrypoints on SILBuilder yet. I want to do this in
two parts so that it is functionally easier to disentangle changing the APIs
above SILBuilder and changing the underlying instruction itself.
rdar://33440767
