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author | Xavier Leroy <xavier.leroy@inria.fr> | 2015-01-01 11:08:12 +0100 |
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committer | Xavier Leroy <xavier.leroy@inria.fr> | 2015-01-01 11:08:12 +0100 |
commit | 442e3140f4a2172bbc1ee7ce260eb1a8fd79ae95 (patch) | |
tree | 9dc3613e16330410d361b43cc4f68b1a042c2012 /cparser/Cutil.mli | |
parent | 1379deed055fc6b1462915a0177e75f4f9a127eb (diff) | |
download | compcert-442e3140f4a2172bbc1ee7ce260eb1a8fd79ae95.tar.gz compcert-442e3140f4a2172bbc1ee7ce260eb1a8fd79ae95.zip |
Revised type compatibility check w.r.t. handling of attributes.
We now distinguish 3 modes (instead of 2 previously) for attributes: 1- strict compatibility, 2- ignore top-level attrs, 3- ignore all attrs recursively.
In strict mode, const/volatile/restrict attributes must be identical, but nonstandard attributes may vary.
Also: ignore top-level attrs when comparing function argument types, like GCC/Clang do.
Net result is fewer warnings and type-checking that is closer to GCC/Clang.
Diffstat (limited to 'cparser/Cutil.mli')
-rw-r--r-- | cparser/Cutil.mli | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/cparser/Cutil.mli b/cparser/Cutil.mli index 309981be..53bcfcea 100644 --- a/cparser/Cutil.mli +++ b/cparser/Cutil.mli @@ -58,12 +58,28 @@ val attr_inherited_by_members: attribute -> bool (* Is an attribute of a composite inherited by members of the composite? *) (* Type compatibility *) -val compatible_types : ?noattrs: bool -> Env.t -> typ -> typ -> bool + +type attr_handling = + | AttrCompat + | AttrIgnoreTop + | AttrIgnoreAll + +val compatible_types : attr_handling -> Env.t -> typ -> typ -> bool (* Check that the two given types are compatible. - If [noattrs], ignore attributes (recursively). *) -val combine_types : ?noattrs: bool -> Env.t -> typ -> typ -> typ option + The attributes in the types are compared according to the first argument: +- [AttrCompat]: the types must have the same standard attributes + ([const], [volatile], [restrict]) but may differ on custom attributes. +- [AttrIgnoreTop]: the top-level attributes of the two types are ignored, + but attributes of e.g. types of pointed objects (for pointer types) + are compared as per [AttrCompat]. +- [AttrIgnoreAll]: recursively ignore the attributes in the two types. *) +val combine_types : attr_handling -> Env.t -> typ -> typ -> typ option (* Like [compatible_types], but if the two types are compatible, - return the most precise type compatible with both. *) + return the most precise type compatible with both. + The attributes are compared according to the first argument, + with the same meaning as for [compatible_types]. + When two sets of attributes are compatible, the result of + [combine_types] carries the union of these two sets of attributes. *) (* Size and alignment *) |