Fortran: How to include "$" in variable and function names

[navinp0304]

I want to index some fortran files from old code base .
The syntax is f77. In the old code base the identifiers are having $ for variable names and functions.

1. How include "$" in the indentifier ?
2. Is there a way without modifying source code ? What would be the command.

[masatake]

How include "$" in the identifier ?

With patching this source of ctags:

diff --git a/parsers/fortran.c b/parsers/fortran.c
index 1c1175b3f..0f5b582dc 100644
--- a/parsers/fortran.c
+++ b/parsers/fortran.c
@@ -31,7 +31,7 @@
 /*
 *   MACROS
 */
-#define isident(c)              (isalnum(c) || (c) == '_')
+#define isident(c)              (isalnum(c) || (c) == '_' || (c) == '$')
 #define isBlank(c)              (bool) (c == ' ' || c == '\t')
 #define isType(token,t)         (bool) ((token)->type == (t))
 #define isKeyword(token,k)      (bool) ((token)->keyword == (k))

2. Is there a way without modifying source code ? What would be the command.

There is no way without modifying the source code.

[masatake]

If you provide a simple f77 input using $, I can extend ctags to support $ by default. Please let me know if you are interested.

[navinp0304]

$ cat tmp.f
        function name$()
                integer name$
                name$ = 42
        end function

        function main()
                integer ret$
                ret$=name$()
                print *,ret$
        end function
$ ./a.out 
          42
$ 

Yes that works for me.
How do you list the regex supported by function in fortran or C for ctags? Is it possible to print it and how do i extend it ?

[masatake]

Based on your input, I made a pull request #4034.

How do you list the regex supported by function in fortran or C for ctags? Is it possible to print it and how do i extend it ?

They don't use regular expressions at all. So you cannot list.

[navinp0304]

Then how do you construct a tag for function in C

[masatake]

Then how do you construct a tag for function in C

Consider the following input as an example:

void foo(void) { ... }

1. read the input file till finding {.
2. if you find {, read backward till finding (.
3. if you find (, read characters satisfying the following condition: 'a' <= character and character <= 'Z' and record the characters to a stack.
4. pick the characters from the stack as a string.
5. write the string as a tag to tags file.

If you want to know the details, see files in https://github.com/universal-ctags/ctags/tree/master/parsers/cxx .