This set of changes implements the Preelaborable_Initialization attribute, corresponding to the existing aspect/pragma, as defined by AI12-0409 (RM2022 10.2.1(11.6/5-11.8/5). This includes semantic checking of restrictions on the prefix, and support for the aspect expression being given by an expression with one or more P_I attributes applied to formal private or derived types, when the type with the aspect is specified on types within a generic package declaration (the value of the aspect in instantiations can be different depending on the actual types), as well as applying preelaborable-initialization restrictions on full types when the partial type has such aspects.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_attr.adb (Expand_N_Attribute_Reference): Fold
Preelaborable_Initialization attribute in cases where it hasn't
been folded by the analyzer.
* exp_disp.adb (Original_View_In_Visible_Part): This function is
removed and moved to sem_util.adb.
* sem_attr.adb (Attribute_22): Add
Attribute_Preelaborable_Initialization as an Ada 2022 attribute.
(Analyze_Attribute, Attribute_Preelaborable_Initialization):
Check that the prefix of the attribute is either a formal
private or derived type, or a composite type declared within the
visible part of a package or generic package.
(Eval_Attribute): Perform folding of
Preelaborable_Initialization attribute based on
Has_Preelaborable_Initialization applied to the prefix type.
* sem_ch3.adb (Resolve_Aspects): Add specialized code for
Preelaborable_Initialization used at the end of a package
visible part for setting Known_To_Have_Preelab_Init on types
that are specified with True or that have a conjunction of one
or more P_I attributes applied to formal types.
* sem_ch7.adb (Analyze_Package_Specification): On call to
Has_Preelaborable_Initialization, pass True for new formal
Formal_Types_Have_Preelab_Init, so that error checking treats
subcomponents that are declared within types in generics as
having preelaborable initialization when the subcomponents are
of formal types.
* sem_ch13.adb (Analyze_Aspects_At_Freeze_Point): Add test for
P_I to prevent calling Make_Pragma_From_Boolean_Aspect, since
this aspect is handled specially and the
Known_To_Have_Preelab_Init flag will get set on types that have
the aspect by other means.
(Analyze_Aspect_Specifications.Analyze_One_Aspect): Add test for
Aspect_Preelaborable_Initialization for allowing the aspect to
be specified on formal type declarations.
(Is_Operational_Item): Treat Attribute_Put_Image as an
operational attribute. The need for this was encountered while
working on these changes.
* sem_util.ads (Has_Preelaborable_Initialization): Add
Formal_Types_Have_Preelab_Init as a new formal parameter that
defaults to False.
(Is_Conjunction_Of_Formal_Preelab_Init_Attributes): New
function.
(Original_View_In_Visible_Part): Moved here from exp_disp.adb,
so it can be called by Analyze_Attribute.
* sem_util.adb (Has_Preelaborable_Initialization): Return True
for formal private and derived types when new formal
Formal_Types_Have_Preelab_Init is True, and pass along the
Formal_Types_Have_Preelab_Init flag in the array component case.
(Check_Components): Pass along Formal_Types_Have_Preelab_Init
flag on call to Has_Preelaborable_Initialization.
(Is_Conjunction_Of_Formal_Preelab_Init_Attributes): New function
that returns True when passed an expression that includes one or
more attributes for Preelaborable_Initialization applied to
prefixes that denote formal types.
(Is_Formal_Preelab_Init_Attribute): New utility function nested
within Is_Conjunction_Of_Formal_Preelab_Init_Attributes that
determines whether a node is a P_I attribute applied to a
generic formal type.
(Original_View_In_Visible_Part): Moved here from exp_util.adb,
so it can be called by Analyze_Attribute.
* snames.ads-tmpl: Add note near the start of spec giving
details about what needs to be done when adding a name that
corresponds to both an attribute and a pragma. Delete existing
occurrence of Name_Preelaborable_Initialization, and add a note
comment in the list of Name_* constants at that place,
indicating that it's included in type Pragma_Id, etc., echoing
other such comments for names that are both an attribute and a
pragma. Insert Name_Preelaborable_Initialization in the
alphabetized set of Name_* constants corresponding to
attributes (between First_Attribute_Name and
Last_Attribute_Name).
(type Attribute_Id): Add new literal
Attribute_Preelaborable_Initialization.
(type Pragma_Id): Move Pragma_Preelaborable_Initialization from
its current position to the end of the type, in the special set
of pragma literals that have corresponding atttributes. Add to
accompanying comment, indicating that functions Get_Pragma_Id
and Is_Pragma_Name need to be updated when adding a pragma
literal to the special set.
* snames.adb-tmpl (Get_Pragma_Id): Add case alternative for
Pragma_Preelaborable_Initialization.
(Is_Pragma_Name): Add test for
Name_Preelaborable_Initialization.
patch.diff.gz
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