From 35729d9fc588d14db92596cbc78ae2818e441661 Mon Sep 17 00:00:00 2001
From: Shuhei Kadowaki <40514306+aviatesk@users.noreply.github.com>
Date: Wed, 18 Dec 2024 00:49:21 +0900
Subject: [PATCH] inference: handle cases where `:the_exception` is used
 independently (#56836)

`Expr(:the_exception)` is handled by the interpreter in all cases,
however, inference assumes it is only used within frames containing
`try/catch`. This commit corrects that assumption.
---
 Compiler/src/abstractinterpretation.jl | 12 ++++++++++--
 Compiler/test/inference.jl             | 14 ++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Compiler/src/abstractinterpretation.jl b/Compiler/src/abstractinterpretation.jl
index 2efd8a2b7264f..0d0d4a2f80e9e 100644
--- a/Compiler/src/abstractinterpretation.jl
+++ b/Compiler/src/abstractinterpretation.jl
@@ -3240,8 +3240,16 @@ function abstract_eval_throw_undef_if_not(interp::AbstractInterpreter, e::Expr,
 end
 
 function abstract_eval_the_exception(::AbstractInterpreter, sv::InferenceState)
-    (;handlers, handler_at) = sv.handler_info::HandlerInfo
-    return the_exception_info(handlers[handler_at[sv.currpc][2]].exct)
+    (;handler_info) = sv
+    if handler_info === nothing
+        return the_exception_info(Any)
+    end
+    (;handlers, handler_at) = handler_info
+    handler_id = handler_at[sv.currpc][2]
+    if handler_id === 0
+        return the_exception_info(Any)
+    end
+    return the_exception_info(handlers[handler_id].exct)
 end
 abstract_eval_the_exception(::AbstractInterpreter, ::IRInterpretationState) = the_exception_info(Any)
 the_exception_info(@nospecialize t) = RTEffects(t, Union{}, Effects(EFFECTS_TOTAL; consistent=ALWAYS_FALSE))
diff --git a/Compiler/test/inference.jl b/Compiler/test/inference.jl
index e272ff6de8d99..132e1e2c14bad 100644
--- a/Compiler/test/inference.jl
+++ b/Compiler/test/inference.jl
@@ -6125,3 +6125,17 @@ function func_swapglobal!_must_throw(x)
 end
 @test Base.infer_return_type(func_swapglobal!_must_throw, (Int,); interp=SwapGlobalInterp()) === Union{}
 @test !Compiler.is_effect_free(Base.infer_effects(func_swapglobal!_must_throw, (Int,); interp=SwapGlobalInterp()) )
+
+@eval get_exception() = $(Expr(:the_exception))
+@test Base.infer_return_type() do
+    get_exception()
+end <: Any
+@test @eval Base.infer_return_type((Float64,)) do x
+    out = $(Expr(:the_exception))
+    try
+        out = sin(x)
+    catch
+        out = $(Expr(:the_exception))
+    end
+    return out
+end == Union{Float64,DomainError}