13.5 Examples of gnatxref Usage

13.5.1 General Usage

For the following examples, we will consider the following units:

     

     main.ads:
     1: with Bar;
     2: package Main is
     3:     procedure Foo (B : in Integer);
     4:     C : Integer;
     5: private
     6:     D : Integer;
     7: end Main;
     
     main.adb:
     1: package body Main is
     2:     procedure Foo (B : in Integer) is
     3:     begin
     4:        C := B;
     5:        D := B;
     6:        Bar.Print (B);
     7:        Bar.Print (C);
     8:     end Foo;
     9: end Main;
     
     bar.ads:
     1: package Bar is
     2:     procedure Print (B : Integer);
     3: end bar;
     

The first thing to do is to recompile your application (for instance, in that case just by doing a ‘gnatmake main’, so that GNAT generates the cross-referencing information. You can then issue any of the following commands:

gnatxref main.adb

gnatxref generates cross-reference information for main.adb and every unit 'with'ed by main.adb.

The output would be:

          B                                                      Type: Integer
            Decl: bar.ads           2:22
          B                                                      Type: Integer
            Decl: main.ads          3:20
            Body: main.adb          2:20
            Ref:  main.adb          4:13     5:13     6:19
          Bar                                                    Type: Unit
            Decl: bar.ads           1:9
            Ref:  main.adb          6:8      7:8
                 main.ads           1:6
          C                                                      Type: Integer
            Decl: main.ads          4:5
            Modi: main.adb          4:8
            Ref:  main.adb          7:19
          D                                                      Type: Integer
            Decl: main.ads          6:5
            Modi: main.adb          5:8
          Foo                                                    Type: Unit
            Decl: main.ads          3:15
            Body: main.adb          2:15
          Main                                                    Type: Unit
            Decl: main.ads          2:9
            Body: main.adb          1:14
          Print                                                   Type: Unit
            Decl: bar.ads           2:15
            Ref:  main.adb          6:12     7:12

that is the entity Main is declared in main.ads, line 2, column 9, its body is in main.adb, line 1, column 14 and is not referenced any where.

The entity Print is declared in bar.ads, line 2, column 15 and it it referenced in main.adb, line 6 column 12 and line 7 column 12.

gnatxref package1.adb package2.ads

gnatxref will generates cross-reference information for package1.adb, package2.ads and any other package 'with'ed by any of these.

13.5.2 Using gnatxref with vi

gnatxref can generate a tags file output, which can be used directly from vi. Note that the standard version of vi will not work properly with overloaded symbols. Consider using another free implementation of vi, such as vim.

     $ gnatxref -v gnatfind.adb > tags

will generate the tags file for gnatfind itself (if the sources are in the search path!).

From vi, you can then use the command ‘:tag entity’ (replacing entity by whatever you are looking for), and vi will display a new file with the corresponding declaration of entity.