The previous lazy discovery did not always work because sometimes a debug_value
is emitted before the first SIL instruction in the variable's scope.
rdar://110841130
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
This leads to an assertion failure in IRGen. A `guard let foo = foo` statement
needs to introduce a new lexical scope so the newely introduced binding can be
distinguished from the one it shadows.
rdar://86579287
