Merge branch 'topic/codepeer_gcc_fallback' into 'master'

Only use codeper-gprbuild/gcc as fallback

Closes #462

See merge request eng/libadalang/langkit-query-language!444

Author: thvnx

lkql_checker/src/gnatcheck-compiler.adb

@@ -1547,28 +1547,40 @@ package body Gnatcheck.Compiler is
       end if;
    end Restriction_Rule_Parameter;
 
-   ----------------------------
-   -- Has_Access_To_Codepeer --
-   ----------------------------
+   --------------------------------
+   -- Should_Use_Codepeer_Target --
+   --------------------------------
 
-   function Has_Access_To_Codepeer return Boolean is
-      Gnatls : String_Access := Locate_Exec_On_Path ("codepeer-gnatls");
-      Res    : Boolean := False;
+   function Should_Use_Codepeer_Target return Boolean is
+      Regular_Gnatls : String_Access := Locate_Exec_On_Path ("gnatls");
    begin
-      if Gnatls /= null then
-         Res := True;
-         Free (Gnatls);
+      --  If we could find a regular gnatls, it means there is a native
+      --  toolchain, that takes precedence over a potential codepeer toolchain.
+      if Regular_Gnatls /= null then
+         Free (Regular_Gnatls);
+         return False;
       end if;
-      return Res;
-   end Has_Access_To_Codepeer;
+
+      --  If we couldn't, look for a codepeer toolchain.
+      declare
+         Gnatls : String_Access := Locate_Exec_On_Path ("codepeer-gnatls");
+      begin
+         if Gnatls /= null then
+            Free (Gnatls);
+            return True;
+         end if;
+      end;
+
+      return False;
+   end Should_Use_Codepeer_Target;
 
    -------------------
    -- GPRbuild_Exec --
    -------------------
 
    function GPRbuild_Exec return String is
    begin
-      if Has_Access_To_Codepeer then
+      if Should_Use_Codepeer_Target then
          return "codepeer-gprbuild";
       else
          return "gprbuild";
@@ -1674,7 +1686,7 @@ package body Gnatcheck.Compiler is
          if Target /= Null_Unbounded_String then
             Num_Args := @ + 1;
             Args (Num_Args) := new String'("--target=" & To_String (Target));
-         elsif Has_Access_To_Codepeer then
+         elsif Should_Use_Codepeer_Target then
             Num_Args := @ + 1;
             Args (Num_Args) := new String'("--target=codepeer");
          end if;
@@ -1821,7 +1833,7 @@ package body Gnatcheck.Compiler is
       Args (8) := new String'("--restricted-to-languages=ada");
       Num_Args := 8;
 
-      if Has_Access_To_Codepeer then
+      if Should_Use_Codepeer_Target then
          Num_Args := @ + 1;
          Args (Num_Args) := new String'("--target=codepeer");
       end if;

lkql_checker/src/gnatcheck-compiler.ads

@@ -18,10 +18,10 @@ package Gnatcheck.Compiler is
    -- Runtime helpers --
    ---------------------
 
-   function Has_Access_To_Codepeer return Boolean;
-   --  Returns whether the current gnatcheck process can access to the codepeer
+   function Should_Use_Codepeer_Target return Boolean;
+   --  Returns whether the current gnatcheck process should use the codepeer
    --  tools. This function tests if the `codepeer-gnatls` executable can be
-   --  accessed.
+   --  accessed when no other regular toolchain can be found.
 
    function GPRbuild_Exec return String;
    --  Return the executable name to use in order to spawn a GPRBuild process

lkql_checker/src/gnatcheck-projects.adb

@@ -804,7 +804,7 @@ package body Gnatcheck.Projects is
 
    procedure Set_Default_Target is
    begin
-      if not Gnatkp_Mode and then Has_Access_To_Codepeer then
+      if not Gnatkp_Mode and then Should_Use_Codepeer_Target then
          GPR2.KB.Set_Default_Target ("codepeer");
       end if;
    end Set_Default_Target;