Merge branch 'topic/rules/fix_identifier_prefixes' into 'master'

Restore old behavior of the "Identifier_Prefixes" rule regarding formal object declarations

Closes #530

See merge request eng/libadalang/langkit-query-language!518

Author: HugoGGuerrier

lkql_checker/doc/generated/predefined_rules.rst

@@ -5724,7 +5724,13 @@ rule options files:
 *Constant: string*
    Specifies the prefix for defining names from constants and named number
    declarations, including the object renaming declaration if the
-   renamed object is a constant
+   renamed object is a constant.
+
+   .. attention::
+      For legacy reasons, formal object declarations are not
+      considered constant, even if they are declared with the ``in`` mode. Consequently,
+      this rule will flag each generic formal object declarations that have the prefix
+      specified by this parameter value.
 
 *Enum: string*
    Specifies the prefix for defining enumeration literals and for the

lkql_checker/share/lkql/identifier_prefixes.lkql

@@ -99,7 +99,13 @@ fun identifier_prefixes(
     |" *Constant: string*
     |"    Specifies the prefix for defining names from constants and named number
     |"    declarations, including the object renaming declaration if the
-    |"    renamed object is a constant
+    |"    renamed object is a constant.
+    |"
+    |"    .. attention::
+    |"       For legacy reasons, formal object declarations are not
+    |"       considered constant, even if they are declared with the ``in`` mode. Consequently,
+    |"       this rule will flag each generic formal object declarations that have the prefix
+    |"       specified by this parameter value.
     |"
     |" *Enum: string*
     |"    Specifies the prefix for defining enumeration literals and for the
@@ -385,7 +391,7 @@ fun identifier_prefixes(
             | p => match p.parent
                 # Constants
                 | (
-                    ObjectDecl(p_is_constant_object(): true)
+                    ObjectDecl(p_is_constant_object(): true, parent: not GenericFormalObjDecl)
                     | NumberDecl
                 ) =>
                     check_prefix_and_exclusive(

testsuite/tests/checks/identifier_prefixes/prefix.ads

@@ -29,6 +29,13 @@ package Prefix is
    --  constant via renames
    Const3   : Type_Enum_1 renames Const_C1;  --  FLAG
 
+   --  formal decls
+   generic
+      Gen_Param       : Integer;             --  NOFLAG
+      Const_Gen_Param : Integer;             --  FLAG
+   package Gen_Pkg is
+   end;
+
    --  exception
    X_Exc_1 : exception;
    Exc_2   : exception;                      --  FLAG

testsuite/tests/checks/identifier_prefixes/test.out

@@ -38,39 +38,43 @@ prefix.ads:30:4: rule violation: Const3 does not start with constant prefix Cons
 30 |    Const3   : Type_Enum_1 renames Const_C1;  --  FLAG
    |    ^^^^^^
 
-prefix.ads:34:4: rule violation: Exc_2 does not start with exception prefix X_
-34 |    Exc_2   : exception;                      --  FLAG
+prefix.ads:35:7: rule violation: Const_Gen_Param is not a constant but starts with Const_
+35 |       Const_Gen_Param : Integer;             --  FLAG
+   |       ^^^^^^^^^^^^^^^
+
+prefix.ads:41:4: rule violation: Exc_2 does not start with exception prefix X_
+41 |    Exc_2   : exception;                      --  FLAG
    |    ^^^^^
 
-prefix.ads:38:9: rule violation: Root2 does not start with derived prefix Root_
-38 |    type Root2 is new Root;                   --  FLAG
+prefix.ads:45:9: rule violation: Root2 does not start with derived prefix Root_
+45 |    type Root2 is new Root;                   --  FLAG
    |         ^^^^^
 
-prefix.ads:39:9: rule violation: Root_1 does not start with subtype prefix Type_
-39 |    type Root_1 is new Integer;               --  FLAG
+prefix.ads:46:9: rule violation: Root_1 does not start with subtype prefix Type_
+46 |    type Root_1 is new Integer;               --  FLAG
    |         ^^^^^^
 
-prefix.ads:45:9: rule violation: Root4 does not start with derived prefix Root_
-45 |    type Root4 is new Type_Sub2;              --  FLAG
+prefix.ads:52:9: rule violation: Root4 does not start with derived prefix Root_
+52 |    type Root4 is new Type_Sub2;              --  FLAG
    |         ^^^^^
 
-prefix.ads:52:14: rule violation: My_Task does not start with concurrent prefix Type_Conc_
-52 |    task type My_Task is                      --  FLAG
+prefix.ads:59:14: rule violation: My_Task does not start with concurrent prefix Type_Conc_
+59 |    task type My_Task is                      --  FLAG
    |              ^^^^^^^
 
-prefix.ads:60:19: rule violation: My_Protected does not start with concurrent prefix Type_Conc_
-60 |    protected type My_Protected is            --  FLAG
+prefix.ads:67:19: rule violation: My_Protected does not start with concurrent prefix Type_Conc_
+67 |    protected type My_Protected is            --  FLAG
    |                   ^^^^^^^^^^^^
 
-prefix.ads:64:9: rule violation: Type_Conc_Rec is not a concurrent but starts with Type_Conc_
-64 |    type Type_Conc_Rec is null record;        --  FLAG
+prefix.ads:71:9: rule violation: Type_Conc_Rec is not a concurrent but starts with Type_Conc_
+71 |    type Type_Conc_Rec is null record;        --  FLAG
    |         ^^^^^^^^^^^^^
 
-prefix.ads:65:9: rule violation: Type_Conc_Der is not a concurrent but starts with Type_Conc_
-65 |    type Type_Conc_Der is new Integer;        --  FLAG
+prefix.ads:72:9: rule violation: Type_Conc_Der is not a concurrent but starts with Type_Conc_
+72 |    type Type_Conc_Der is new Integer;        --  FLAG
    |         ^^^^^^^^^^^^^
 
-prefix.ads:67:4: rule violation: Const_Or_Node is not a constant but starts with Const_
-67 |    Const_Or_Node : Integer := 1;             --  FLAG
+prefix.ads:74:4: rule violation: Const_Or_Node is not a constant but starts with Const_
+74 |    Const_Or_Node : Integer := 1;             --  FLAG
    |    ^^^^^^^^^^^^^