diff options
Diffstat (limited to 'gcc/ada/gcc-interface/decl.c')
| -rw-r--r-- | gcc/ada/gcc-interface/decl.c | 32 |
1 files changed, 19 insertions, 13 deletions
diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c index 188b896..22ca3a5 100644 --- a/gcc/ada/gcc-interface/decl.c +++ b/gcc/ada/gcc-interface/decl.c @@ -3739,7 +3739,19 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) bool public_flag = Is_Public (gnat_entity) || imported_p; bool extern_flag = (Is_Public (gnat_entity) && !definition) || imported_p; - bool pure_flag = Is_Pure (gnat_entity); + + /* The semantics of "pure" in Ada essentially matches that of "const" + in the back-end. In particular, both properties are orthogonal to + the "nothrow" property if the EH circuitry is explicit in the + internal representation of the back-end. If we are to completely + hide the EH circuitry from it, we need to declare that calls to pure + Ada subprograms that can throw have side effects since they can + trigger an "abnormal" transfer of control flow; thus they can be + neither "const" nor "pure" in the back-end sense. */ + bool const_flag + = (Exception_Mechanism == Back_End_Exceptions + && Is_Pure (gnat_entity)); + bool volatile_flag = No_Return (gnat_entity); bool returns_by_ref = false; bool returns_unconstrained = false; @@ -3972,12 +3984,12 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) /* If a parameter is a pointer, this function may modify memory through it and thus shouldn't be considered - a pure function. Also, the memory may be modified + a const function. Also, the memory may be modified between two calls, so they can't be CSE'ed. The latter case also handles by-ref parameters. */ if (POINTER_TYPE_P (gnu_param_type) || TYPE_FAT_POINTER_P (gnu_param_type)) - pure_flag = false; + const_flag = false; } if (copy_in_copy_out) @@ -4054,21 +4066,16 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) returns_by_ref, returns_by_target_ptr); /* A subprogram (something that doesn't return anything) shouldn't - be considered Pure since there would be no reason for such a + be considered const since there would be no reason for such a subprogram. Note that procedures with Out (or In Out) parameters have already been converted into a function with a return type. */ if (TREE_CODE (gnu_return_type) == VOID_TYPE) - pure_flag = false; - - /* The semantics of "pure" in Ada used to essentially match that of - "const" in the middle-end. In particular, both properties were - orthogonal to the "nothrow" property. This is not true in the - middle-end any more and we have no choice but to ignore the hint - at this stage. */ + const_flag = false; gnu_type = build_qualified_type (gnu_type, TYPE_QUALS (gnu_type) + | (TYPE_QUAL_CONST * const_flag) | (TYPE_QUAL_VOLATILE * volatile_flag)); Sloc_to_locus (Sloc (gnat_entity), &input_location); @@ -4077,8 +4084,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition) gnu_stub_type = build_qualified_type (gnu_stub_type, TYPE_QUALS (gnu_stub_type) - | (Exception_Mechanism == Back_End_Exceptions - ? TYPE_QUAL_CONST * pure_flag : 0) + | (TYPE_QUAL_CONST * const_flag) | (TYPE_QUAL_VOLATILE * volatile_flag)); /* If we have a builtin decl for that function, check the signatures |