wip: reasons about concrete evaluation

src/abstractinterpret/abstractanalyzer.jl

@@ -510,6 +510,7 @@ end
 # otherwise, it means malformed report pass call, and we should inform users of it
 function (rp::ReportPass)(T, @nospecialize(args...))
     if !(T === NativeRemark ||
+         T === ConcreteError ||
          T === InvalidConstantRedefinition ||
          T === InvalidConstantDeclaration)
         throw(MethodError(rp, (T, args...)))

src/abstractinterpret/typeinfer.jl

@@ -235,12 +235,39 @@ end # @static if IS_V18
 # TODO correctly reasons about error found by concrete evaluation
 # for now just always fallback to the constant-prop'
 @static if IS_V18
-function CC.concrete_eval_eligible(analyzer::AbstractAnalyzer,
+function CC.concrete_eval_call(analyzer::AbstractAnalyzer,
     @nospecialize(f), result::MethodCallResult, arginfo::ArgInfo, sv::InferenceState)
-    return false
+    CC.concrete_eval_eligible(analyzer, f, result, arginfo, sv) || return nothing
+    # this frame is happily concretizable, now let's throw away reports collected from
+    # the previous abstract interpretation and just trust the concrete runtime evaluation
+    filter_lineages!(analyzer, sv.result, result.edge)
+    args = CC.collect_const_args(arginfo)
+    world = get_world_counter(analyzer)
+    value = try
+        Core._call_in_world_total(world, f, args...)
+    catch err
+        # NOTE this report pass allows analyzers to opt in to report concretized errors
+        ReportPass(analyzer)(ConcreteError, analyzer, sv, err)
+
+        # The evaulation threw. By :consistent-cy, we're guaranteed this would have happened at runtime
+        return CC.ConstCallResults(Union{}, CC.ConstResult(result.edge, result.edge_effects), result.edge_effects)
+    end
+    if CC.is_inlineable_constant(value) || CC.call_result_unused(sv)
+        # If the constant is not inlineable, still do the const-prop, since the
+        # code that led to the creation of the Const may be inlineable in the same
+        # circumstance and may be optimizable.
+        return CC.ConstCallResults(Const(value), CC.ConstResult(result.edge, CC.EFFECTS_TOTAL, value), CC.EFFECTS_TOTAL)
+    end
+    return nothing
 end
 end # @static if IS_V18
 
+@reportdef struct ConcreteError <: InferenceErrorReport
+    @nospecialize(err)
+end
+get_msg(::Type{ConcreteError}, sv::InferenceState, @nospecialize(err)) =
+    "will throw `$(typeof(err))`"
+
 @static if IS_AFTER_42529
 function CC.abstract_call(analyzer::AbstractAnalyzer,
     arginfo::ArgInfo, sv::InferenceState, max_methods::Int = InferenceParams(analyzer).MAX_METHODS)
@@ -643,7 +670,12 @@ function islineage(parent::MethodInstance, current::MethodInstance)
             vst = report.vst
             length(vst) > 1 || return false
             vst[1].linfo === parent || return false
-            return vst[2].linfo === current
+            if vst[2].linfo === current
+                # @info "remove" report
+                return true
+            else
+                return false
+            end
         end
     end
 end

src/analyzers/jetanalyzer.jl

@@ -254,10 +254,16 @@ function (::BasicPass)(::Type{UncaughtExceptionReport}, analyzer::JETAnalyzer, f
         report_uncaught_exceptions!(analyzer, frame, stmts)
         return true
     else
-        # the non-`Bottom` result may mean `throw` calls from the children frames
-        # (if exists) are caught and not propagated here
-        # we don't want to cache the caught `UncaughtExceptionReport`s for this frame and
-        # its parents, and just filter them away now
+        # the non-`Bottom` result mean `throw` calls or concretized calls within child frames
+        # (if exists) can be caught or necessarily don't happen here:
+        # for `BasicPass` we don't want to cache such reports for this frame and not propagate
+        # them to parent frames, so just throw them away now
+        # TODO this is not best place to do this
+        filter!(get_reports(analyzer, frame.result)) do report
+            report isa UncaughtExceptionReport && return false
+            # report isa ConcreteError && return false
+            return true
+        end
         filter!(report->!isa(report, UncaughtExceptionReport), get_reports(analyzer, frame.result))
     end
     return false
@@ -479,6 +485,13 @@ must-reachable `throw` calls.
 """
 CC.const_prop_entry_heuristic(::JETAnalyzer, result::MethodCallResult, sv::InferenceState) = true
 
+@static if IS_V18
+function (::SoundBasicPass)(::Type{ConcreteError}, analyzer::AbstractAnalyzer, sv::InferenceState, @nospecialize(err))
+    add_new_report!(analyzer, sv.result, ConcreteError(sv, err))
+    return true
+end
+end # @static if IS_V18
+
 function CC.return_type_tfunc(analyzer::JETAnalyzer, argtypes::Argtypes, sv::InferenceState)
     # report pass for invalid `Core.Compiler.return_type` call
     ReportPass(analyzer)(InvalidReturnTypeCall, analyzer, sv, argtypes)

test/abstractinterpret/test_typeinfer.jl

@@ -252,8 +252,7 @@ end
 
 @testset "integration with global code cache" begin
     # analysis for `sum(::String)` is already cached, `sum′` and `sum′′` should use it
-    let
-        m = gen_virtual_module()
+    let m = Module()
         result = Core.eval(m, quote
             sum′(s) = sum(s)
             sum′′(s) = sum′(s)
@@ -265,8 +264,7 @@ end
     end
 
     # incremental setup
-    let
-        m = gen_virtual_module()
+    let m = Module()
 
         result = Core.eval(m, quote
             $report_call() do
@@ -567,6 +565,55 @@ end
     end
 end
 
+@static if isdefined(Base, Symbol("@assume_effects"))
+Base.@assume_effects :terminates_locally function pow(x)
+    # this :terminates_locally allows `pow` to be constant-folded
+    res = 1
+    1 < x < 20 || error("bad pow")
+    while x > 1
+        res *= x
+        x -= 1
+    end
+    return res
+end
+function concretize_pow(n)
+    v = pow(n)
+    if v == 120
+        return v
+    else
+        return nothing
+    end
+end
+
+Base.@assume_effects :total_may_throw concretize(f, args...) = f(args...)
+
+@testset "concrete evaluation" begin
+    test_call((Int,)) do x
+        concretize_pow(5) + x
+    end
+
+    let result = report_call((Int,)) do x
+            concretize_pow(42) + x # `ErrorException` should be reported
+        end
+        report = only(get_reports(result))
+        @test report isa ConcreteError
+        @test report.err == ErrorException("bad pow")
+    end
+
+    # throw away errors found by previous abstract interpretation
+    # this case especially shouldn't report possible errors by `sum(::String)`
+    test_call() do
+        concretize("julia") do x
+            if hasmethod(length, (typeof(x),))
+                return length(x)
+            else
+                return sum(x)
+            end
+        end
+    end
+end
+end # @static if isdefined(Base, Symbol("@assume_effects"))
+
 @testset "additional analysis pass for task parallelism code" begin
     # general case with `schedule(::Task)` pattern
     result = report_call() do