Marek Polacek
7482d5a3ac
In this testcase we are crashing trying to gimplify a switch, because
the types of the switch condition and case constants have different
TYPE_PRECISIONs.
This started with my r5-3726 fix: SWITCH_STMT_TYPE is supposed to be the
original type of the switch condition before any conversions, so in the
C++ FE we need to use unlowered_expr_type to get the unlowered type of
enum bit-fields.
Normally, the switch type is subject to integral promotions, but here
we have a scoped enum type and those don't promote:
enum class B { A };
struct C { B c : 8; };
switch (x.c) // type B
case B::A: // type int, will be converted to B
Here TREE_TYPE is "signed char" but SWITCH_STMT_TYPE is "B". When
gimplifying this in gimplify_switch_expr, the index type is "B" and
we convert all the case values to "B" in preprocess_case_label_vec,
but SWITCH_COND is of type "signed char": gimple_switch_index should
be the (possibly promoted) type, not the original type, so we gimplify
the "x.c" SWITCH_COND to a SSA_NAME of type "signed char". And then
we crash because the precision of the index type doesn't match the
precision of the case value type.
I think it makes sense to do the following; at the end of pop_switch
we've already issued the switch warnings, and since scoped enums don't
promote, it should be okay to use the type of SWITCH_STMT_COND. The
r5-3726 change was about giving warnings for enum bit-fields anyway.
gcc/cp/ChangeLog:
PR c++/98043
* decl.c (pop_switch): If SWITCH_STMT_TYPE is a scoped enum type,
set it to the type of SWITCH_STMT_COND.
gcc/testsuite/ChangeLog:
PR c++/98043
* g++.dg/cpp0x/enum41.C: New test.
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