The compiler incorrectly assumed the prefix for a slice returned in one
branch of an if expression has its bounds known at compile time and would
crash when this is not true.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_ch4.adb (Expand_N_If_Expression): Test for compile time
known bounds when handling slices.diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -6174,7 +6174,13 @@ package body Exp_Ch4 is
Slice_Bnd : Node_Id) return Node_Id is
begin
- if Nkind (Elsex) = N_Slice then
+ -- We need to use the special processing for slices only if
+ -- they do not have compile-time known bounds; if they do, they
+ -- can be treated like any other expressions.
+
+ if Nkind (Elsex) = N_Slice
+ and then not Compile_Time_Known_Bounds (Etype (Elsex))
+ then
if Compile_Time_Known_Value (Slice_Bnd)
and then Expr_Value (Slice_Bnd) = Then_Bnd
then
@@ -6230,7 +6236,11 @@ package body Exp_Ch4 is
begin
Get_First_Index_Bounds (Etype (Thenx), Then_Lo, Then_Hi);
- if Nkind (Elsex) = N_Slice then
+ -- See the rationale in Build_New_Bound
+
+ if Nkind (Elsex) = N_Slice
+ and then not Compile_Time_Known_Bounds (Etype (Elsex))
+ then
Slice_Lo := Low_Bound (Discrete_Range (Elsex));
Slice_Hi := High_Bound (Discrete_Range (Elsex));
Get_First_Index_Bounds
@@ -6289,7 +6299,11 @@ package body Exp_Ch4 is
Set_Suppress_Assignment_Checks (Last (Then_List));
- if Nkind (Elsex) = N_Slice then
+ -- See the rationale in Build_New_Bound
+
+ if Nkind (Elsex) = N_Slice
+ and then not Compile_Time_Known_Bounds (Etype (Elsex))
+ then
Else_List := New_List (
Make_Assignment_Statement (Loc,
Name =>
