Coding Style¶
Ada subset: use only a simple (VHDL like) subset of Ada: no tasking, no controlled types… VHDL users should easily understand that subset. Allowed Ada95 features: the standard library, child packages. Use assertions.
We try to follow the ‘GNU Coding Standards’ when possible: comments before declarations, one space at the end of sentences, finish sentences with a dot. But: 2 spaces for indentation in code blocks.
No trailing spaces, no TAB (HT).
Subprograms must have a comment before to describe them, like:
-- Analyze the concurrent statements of PARENT.
procedure Sem_Concurrent_Statement_Chain (Parent : Iir);
The line before the comment must be a blank line (unless this is the first declaration). Don’t repeat the comment before the subprogram body.
For subprograms:
Declare on one line when possible:
function Translate_Static_Aggregate (Aggr : Iir) return O_Cnode
If not possible, put the return on the next line:
function Translate_Static_String (Str_Type : Iir; Str_Ident : Name_Id) return O_Cnode
If not possible, put parameters and return on the next line:
function Create_String_Literal_Var_Inner (Str : Iir; Element_Type : Iir; Str_Type : O_Tnode) return Var_Type
If not possible, return on the next line:
function Translate_Shortcut_Operator (Imp : Iir_Implicit_Function_Declaration; Left, Right : Iir) return O_Enode
If not possible, one parameter per line, just after subprogram name:
procedure Translate_Static_Aggregate_1 (List : in out O_Array_Aggr_List; Aggr : Iir; Info : Iir; El_Type : Iir)
If not possible, add a return after subprogram name:
function Translate_Predefined_TF_Array_Element (Op : Predefined_Boolean_Logical; Left, Right : Iir; Res_Type : Iir; Loc : Iir) return O_Enode
If not possible, ask yourself what is wrong! Shorten a name.
Rule for the ‘is’: on a new line only if the declarative part is not empty:
procedure Translate_Assign (Target : Mnode; Expr : Iir; Target_Type : Iir) is Val : O_Enode; begin
vs.
function Translate_Static_Range_Dir (Expr : Iir) return O_Cnode is begin
If the parameter line is too long with the ‘is’, put in on a separate line:
procedure Predeclare_Scope_Type (Scope : in out Var_Scope_Type; Name : O_Ident) is
Generic instantiation: put the generic actual part on a new line:
procedure Free is new Ada.Unchecked_Deallocation (Action_List, Action_List_Acc);
For if/then statement:
‘then’ on the same line:
if Get_Expr_Staticness (Decl) = Locally then
If not possible, ‘then’ is alone on its line aligned with the ‘if’:
if Expr = Null_Iir or else Get_Kind (Expr) = Iir_Kind_Overflow_Literal then
For a multiline condition, ‘or else’ and ‘and then’ should start lines.
‘Local’ variable declaration: Do not initialize variables, constants must be declared before variables:
is N_Info : constant Iir := Get_Sub_Aggregate_Info (Info); Assoc : Iir; Sub : Iir; begin
If the initialization expression has a side effect (such as allocation), do not use a constant.