| Message ID | 1396974.au2QbtdziC@polaris |
|---|---|
| State | New |
| Headers | show |
On Mon, Nov 11, 2013 at 11:55 AM, Eric Botcazou <ebotcazou@adacore.com> wrote: > Hi, > > in Ada 2012 it is allowed to omit components of aggregates (the equivalent of > initializers/constructors); in this case, the contents of the corresponding > fields in the record become undefined. Now the gimplifier implements the C > semantics of clearing the missing components, so this patch introduces a new > flag on constructors to modify that. > > Tested on x86_64-suse-linux, OK for the mainline? Ok. Can you update doc/generic.texi? Thanks, Richard. > > 2013-11-11 Tristan Gingold <gingold@adacore.com> > Eric Botcazou <ebotcazou@adacore.com> > > * tree.h (CONSTRUCTOR_NO_CLEARING): Define. > * tree-core.h (CONSTRUCTOR_NO_CLEARING): Document it. > * tree.def (CONSTRUCTOR): Likewise. > * gimplify.c (gimplify_init_constructor): Do not clear the object when > the constructor is incomplete and CONSTRUCTOR_NO_CLEARING is set. > ada/ > * gcc-interface/utils2.c (gnat_build_constructor): Also set the flag > CONSTRUCTOR_NO_CLEARING on the constructor. > > > -- > Eric Botcazou
> Ok. Can you update doc/generic.texi?
Thanks, done (it was still talking about TREE_LIST).
> in Ada 2012 it is allowed to omit components of aggregates (the equivalent > of initializers/constructors); in this case, the contents of the > corresponding fields in the record become undefined. Now the gimplifier > implements the C semantics of clearing the missing components, so this > patch introduces a new flag on constructors to modify that. My bad, I forgot to install the testcase written by Tristan... Tested on x86_64-suse-linux, installed on the mainline. 2013-11-12 Tristan Gingold <gingold@adacore.com> * gnat.dg/aggr21.adb: New test. * gnat.dg/aggr21_pkg.ad[sb]: New helper.
Index: tree-core.h =================================================================== --- tree-core.h (revision 204444) +++ tree-core.h (working copy) @@ -823,6 +823,9 @@ struct GTY(()) tree_base { VAR_DECL, FUNCTION_DECL IDENTIFIER_NODE + CONSTRUCTOR_NO_CLEARING in + CONSTRUCTOR + ASM_VOLATILE_P in ASM_EXPR Index: tree.h =================================================================== --- tree.h (revision 204444) +++ tree.h (working copy) @@ -957,6 +957,8 @@ extern void omp_clause_range_check_faile (&(*CONSTRUCTOR_ELTS (NODE))[IDX]) #define CONSTRUCTOR_NELTS(NODE) \ (vec_safe_length (CONSTRUCTOR_ELTS (NODE))) +#define CONSTRUCTOR_NO_CLEARING(NODE) \ + (CONSTRUCTOR_CHECK (NODE)->base.public_flag) /* Iterate through the vector V of CONSTRUCTOR_ELT elements, yielding the value of each element (stored within VAL). IX must be a scratch variable Index: tree.def =================================================================== --- tree.def (revision 204444) +++ tree.def (working copy) @@ -458,7 +458,10 @@ DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref value in a SAVE_EXPR if you want to evaluate side effects only once.) For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: - The field INDEX of each node is a FIELD_DECL. */ + The field INDEX of each node is a FIELD_DECL. + Components that aren't present are cleared as per the C semantics, + unless the CONSTRUCTOR_NO_CLEARING flag is set, in which case they + become undefined. */ DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0) /* The expression types are mostly straightforward, with the fourth argument Index: gimplify.c =================================================================== --- gimplify.c (revision 204444) +++ gimplify.c (working copy) @@ -4052,7 +4052,7 @@ gimplify_init_constructor (tree *expr_p, objects. Initializers for such objects must explicitly set every field that needs to be set. */ cleared = false; - else if (!complete_p) + else if (!complete_p && !CONSTRUCTOR_NO_CLEARING (ctor)) /* If the constructor isn't complete, clear the whole object beforehand. Index: ada/gcc-interface/utils2.c =================================================================== --- ada/gcc-interface/utils2.c (revision 204444) +++ ada/gcc-interface/utils2.c (working copy) @@ -1874,6 +1874,7 @@ gnat_build_constructor (tree type, vec<c v->qsort (compare_elmt_bitpos); result = build_constructor (type, v); + CONSTRUCTOR_NO_CLEARING (result) = 1; TREE_CONSTANT (result) = TREE_STATIC (result) = allconstant; TREE_SIDE_EFFECTS (result) = side_effects; TREE_READONLY (result) = TYPE_READONLY (type) || allconstant;
Hi, in Ada 2012 it is allowed to omit components of aggregates (the equivalent of initializers/constructors); in this case, the contents of the corresponding fields in the record become undefined. Now the gimplifier implements the C semantics of clearing the missing components, so this patch introduces a new flag on constructors to modify that. Tested on x86_64-suse-linux, OK for the mainline? 2013-11-11 Tristan Gingold <gingold@adacore.com> Eric Botcazou <ebotcazou@adacore.com> * tree.h (CONSTRUCTOR_NO_CLEARING): Define. * tree-core.h (CONSTRUCTOR_NO_CLEARING): Document it. * tree.def (CONSTRUCTOR): Likewise. * gimplify.c (gimplify_init_constructor): Do not clear the object when the constructor is incomplete and CONSTRUCTOR_NO_CLEARING is set. ada/ * gcc-interface/utils2.c (gnat_build_constructor): Also set the flag CONSTRUCTOR_NO_CLEARING on the constructor.