adjust EA to #52527 (#55986)

`EnterNode.catch_dest` can now be `0` after the `try`/`catch` elision
feature implemented in #52527, and we actually need to
adjust `EscapeAnalysis.compute_frameinfo` too.

base/compiler/ssair/EscapeAnalysis/EscapeAnalysis.jl

@@ -732,11 +732,13 @@ function compute_frameinfo(ir::IRCode)
         inst = ir[SSAValue(idx)]
         stmt = inst[:stmt]
         if isa(stmt, EnterNode)
-            @assert idx ≤ nstmts "try/catch inside new_nodes unsupported"
-            tryregions === nothing && (tryregions = UnitRange{Int}[])
             leave_block = stmt.catch_dest
-            leave_pc = first(ir.cfg.blocks[leave_block].stmts)
-            push!(tryregions, idx:leave_pc)
+            if leave_block ≠ 0
+                @assert idx ≤ nstmts "try/catch inside new_nodes unsupported"
+                tryregions === nothing && (tryregions = UnitRange{Int}[])
+                leave_pc = first(ir.cfg.blocks[leave_block].stmts)
+                push!(tryregions, idx:leave_pc)
+            end
         elseif arrayinfo !== nothing
             # TODO this super limited alias analysis is able to handle only very simple cases
             # this should be replaced with a proper forward dimension analysis

test/compiler/EscapeAnalysis/EscapeAnalysis.jl

@@ -2299,4 +2299,21 @@ let result = code_escapes((SafeRef{String},Any)) do x, y
     @test has_all_escape(result.state[Argument(3)])  # y
 end
 
+@eval function scope_folding()
+    $(Expr(:tryfinally,
+        Expr(:block,
+            Expr(:tryfinally, :(), :(), 2),
+            :(return Core.current_scope())),
+    :(), 1))
+end
+@eval function scope_folding_opt()
+    $(Expr(:tryfinally,
+        Expr(:block,
+            Expr(:tryfinally, :(), :(), :(Base.inferencebarrier(2))),
+            :(return Core.current_scope())),
+    :(), :(Base.inferencebarrier(1))))
+end
+@test (@code_escapes scope_folding()) isa EAUtils.EscapeResult
+@test (@code_escapes scope_folding_opt()) isa EAUtils.EscapeResult
+
 end # module test_EA

test/compiler/irpasses.jl

@@ -576,7 +576,6 @@ let # lifting `isa` through Core.ifelse
     @test count(iscall((src, isa)), src.code) == 0
 end
 
-
 let # lifting `isdefined` through PhiNode
     src = code_typed1((Bool,Some{Int},)) do c, x
         y = c ? x : nothing
@@ -1035,8 +1034,7 @@ exc39508 = ErrorException("expected")
 end
 @test test39508() === exc39508
 
-let
-    # `typeassert` elimination after SROA
+let # `typeassert` elimination after SROA
     # NOTE we can remove this optimization once inference is able to reason about memory-effects
     src = @eval Module() begin
         mutable struct Foo; x; end
@@ -1051,8 +1049,7 @@ let
     @test count(iscall((src, typeassert)), src.code) == 0
 end
 
-let
-    # Test for https://github.com/JuliaLang/julia/issues/43402
+let # Test for https://github.com/JuliaLang/julia/issues/43402
     # Ensure that structs required not used outside of the ccall,
     # still get listed in the ccall_preserves