This change improves the circuitry that produces a source-like rendition
for an Ada tree by omitting the generation of extraneous parentheses around
conditional expressions, and removing an extraneous ELSE keyword.
The following compilation must produce the indicated output:
$ gcc -c -gnat12 -gnatG condexpr_sprint.adb
Source recreated from tree for Condexpr_Sprint (body)
procedure condexpr_sprint (b : boolean; i : integer) is
type r is record
bb : boolean := (if b then b);
ii : integer := (case i is when 1 => 1, when others => 2);
end record;
begin
null;
end condexpr_sprint;
condexpr_sprint.adb:2:04: declaration expected
procedure Condexpr_Sprint (B : Boolean; I : Integer) is
zz -- Purposely introduce a serious error here to prevent further analysis
type R is record
BB : Boolean := (if B then B);
II : Integer := (case I is when 1 => 1, when others => 2);
end record;
begin
null;
end Condexpr_Sprint;
Tested on x86_64-pc-linux-gnu, committed on trunk
2013-01-02 Thomas Quinot <[email protected]>
* sprint.adb (Sprint_Node_Actual): Do not add extra parens for
a conditional expression (CASE or IF expression) that already
has parens. Also omit ELSE keyword for an IF expression without
an ELSE part.
Index: sprint.adb
===================================================================
--- sprint.adb (revision 194776)
+++ sprint.adb (working copy)
@@ -1159,14 +1159,19 @@
when N_Case_Expression =>
declare
- Alt : Node_Id;
+ Has_Parens : constant Boolean := Paren_Count (Node) > 0;
+ Alt : Node_Id;
begin
-- The syntax for case_expression does not include parentheses,
-- but sometimes parentheses are required, so unconditionally
- -- generate them here.
+ -- generate them here unless already present.
- Write_Str_With_Col_Check_Sloc ("(case ");
+ if not Has_Parens then
+ Write_Char ('(');
+ end if;
+
+ Write_Str_With_Col_Check_Sloc ("case ");
Sprint_Node (Expression (Node));
Write_Str_With_Col_Check (" is");
@@ -1178,7 +1183,9 @@
Write_Char (',');
end loop;
- Write_Char (')');
+ if not Has_Parens then
+ Write_Char (')');
+ end if;
end;
when N_Case_Expression_Alternative =>
@@ -1963,15 +1970,19 @@
when N_If_Expression =>
declare
- Condition : constant Node_Id := First (Expressions (Node));
- Then_Expr : constant Node_Id := Next (Condition);
+ Has_Parens : constant Boolean := Paren_Count (Node) > 0;
+ Condition : constant Node_Id := First (Expressions (Node));
+ Then_Expr : constant Node_Id := Next (Condition);
begin
-- The syntax for if_expression does not include parentheses,
-- but sometimes parentheses are required, so unconditionally
- -- generate them here.
+ -- generate them here unless already present.
- Write_Str_With_Col_Check_Sloc ("(if ");
+ if not Has_Parens then
+ Write_Char ('(');
+ end if;
+ Write_Str_With_Col_Check_Sloc ("if ");
Sprint_Node (Condition);
Write_Str_With_Col_Check (" then ");
@@ -1979,11 +1990,16 @@
if Present (Then_Expr) then
Sprint_Node (Then_Expr);
- Write_Str_With_Col_Check (" else ");
- Sprint_Node (Next (Then_Expr));
+
+ if Present (Next (Then_Expr)) then
+ Write_Str_With_Col_Check (" else ");
+ Sprint_Node (Next (Then_Expr));
+ end if;
end if;
- Write_Char (')');
+ if not Has_Parens then
+ Write_Char (')');
+ end if;
end;
when N_If_Statement =>
