Detect COBOL variable in EXEC SQL, provides go to def, show refs and hover

[NeoKaios]

Add-on to #370,
reactivate Sql preproc in the LSP and add references and location to cobol vars in sql exec blocks

The completion seems to fails inside such exec blocks -> the parser needs to be more robust
The new completion test needs to pass before merging this

[nberth]

Should be draft until #370 is merged.

[GitMensch]

This seems to target #327, no? If yes I suggest to reference that in the commit message and/or in this PR as related issue.

[nberth]

This PR introduces dependencies between libraries that I'd like to avoid as they would impair further extensibility of the LSP server. In addition the parser for SQL is not hardened against errors in SQL syntax. Those issues need to be fixed before this PR can be merged.

[GitMensch]

I still wonder if it wouldn't be "simple" to not fully parse the SQL stuff (which can be quite useful if it provides completions and co) but just scan it for any doublecolon+word - and add those as a reference for "word"....

[GitMensch]

just checked with last CD build, CTRL+click does not work (so I guess references won't work either), tested on bind variables (:DB and defined cursors MYCUR)

           EXEC SQL AT :DB
               FETCH MYCUR
               INTO
                 :FLD1,
                 :FLD2
           END-EXEC.

and also not in the declaration

           EXEC SQL VAR TABFLD1            IS CHAR      END-EXEC.

Should it?

[nberth]

Should it?

Implicitly declared variables are not supported yet: only references to COBOL variables for which there is a corresponding COBOL declaration can be navigated (and renamed) in this way. I guess this will be future work (and this limitation will need to be documented in the README.md — that does not even mention SQL yet).

[GitMensch]

for the cursors, sure - but FL1 and FLD2 are indeed variables that are part of WORKING-STORAGE, even separate fields

           EXEC SQL BEGIN DECLARE SECTION END-EXEC.
      *
       01 DB                 PIC  X(010).
       01 FLD1               PIC  X(018).
       01 FLD2               PIC  X(026).
      * 
       01 MYTAB.
         03 MYKEY.
           05 FLD3           PIC  X(006).
           05 FLD4           PIC  X(008).
      *
         03 MYDATA.
            05 ...
      * 
           EXEC SQL VAR FLD3            IS CHAR      END-EXEC.
           EXEC SQL VAR FLD4            IS CHAR      END-EXEC.
      * 
           EXEC SQL END DECLARE SECTION END-EXEC.
           EXEC SQL INCLUDE SQLCA END-EXEC.
      *
           EXEC SQL AT :DBS
              DECLARE MYCUR CURSOR FOR
                 SELECT
                        FLD1, FLD2 FROM TAB
                 WHERE
                          TFL3
                       || TFL4
                 >=
                          :FLD3
                       || :FLD4
                 ORDER BY
                          TFL3
                       || TFL4
                 ASC
           END-EXEC.

[nberth]

for the cursors, sure - but FL1 and FLD2 are indeed variables that are part of WORKING-STORAGE, even separate fields

           EXEC SQL BEGIN DECLARE SECTION END-EXEC.
      *
       01 DB                 PIC  X(010).
       01 FLD1               PIC  X(018).
       01 FLD2               PIC  X(026).
      * 
       01 MYTAB.
         03 MYKEY.
           05 FLD3           PIC  X(006).
           05 FLD4           PIC  X(008).
      *
         03 MYDATA.
            05 ...
      * 
           EXEC SQL VAR FLD3            IS CHAR      END-EXEC.
           EXEC SQL VAR FLD4            IS CHAR      END-EXEC.
      * 
           EXEC SQL END DECLARE SECTION END-EXEC.
           EXEC SQL INCLUDE SQLCA END-EXEC.
      *
           EXEC SQL AT :DBS
              DECLARE MYCUR CURSOR FOR
                 SELECT
                        FLD1, FLD2 FROM TAB
                 WHERE
                          TFL3
                       || TFL4
                 >=
                          :FLD3
                       || :FLD4
                 ORDER BY
                          TFL3
                       || TFL4
                 ASC
           END-EXEC.

All of this snippet is in WORKING-STORAGE section, right? It is quite possible that at the moment portions of SQL that appear in this section are only handled for variable declarations, but not for "use" references.

[GitMensch]

yes (that's the place Pro*COB expects it; it possibly doesn't care and only searches for EXEC SQL ... END-EXEC and EXEC SQL DECLARE ... END DECLARE)