This PR updates alpha.webkit.UncountedLocalVarsChecker to emit warnings
for assignments to uncounted local variable and parameters instead of
just the initialization during the declaration.
This PR adds the support for determining the origin of a pointer in a
conditional operator.
Because such an expression can have two distinct origins each of which
needs to be visited, this PR refactors tryToFindPtrOrigin to take a
callback instead of returning a pair.
The callback is called for the second operand and the third operand of
the conditioanl operator (i.e. E2 and E3 in E1 ? E2 : E3).
Also treat nullptr and integer literal as safe pointer origins in the
local variable checker.
This PR makes alpha.webkit.UncountedLocalVarsChecker ignore raw
references and pointers to a ref counted type which appears within
"trival" statements. To do this, this PR extends TrivialFunctionAnalysis
so that it can also analyze "triviality" of statements as well as that
of functions Each Visit* function is now augmented with
withCachedResult, which is responsible for looking up and updating the
cache for each Visit* functions.
As this PR dramatically improves the false positive rate of the checker,
it also deletes the code to ignore raw pointers and references within if
and for statements.
Some of the predicates can't always be decided - for example when a type
definition isn't available. At the same time it's necessary to let
client code decide what to do about such cases - specifically we can't
just use true or false values as there are callees with
conflicting strategies how to handle this.
This is a speculative fix for PR47276.
Differential Revision: https://reviews.llvm.org/D88133
