Creating call graphs for C and FORTRAN programs

Creating a call graph for C or FORTRAN program is pretty simple using GCC.

For both FORTRAN and C programs, the trick is to compile the program using the compiler flag -fdump-rtl-expand (see documentation).

Once the program is compiled, a file with a name like solergya.f.144f.expand will be created.

That file can be easily processed using the Perl-based utility egypt. Download egypt 1.10 from here or use our local copy, egypt-1.10.tar.gz, and to install it use

Invalid language.

You need to specify a language like this: <source lang="html">...</source>

Supported languages for syntax highlighting:

a4c, abap, abc, abnf, actionscript, ada, agda, alan, algol, ampl, amtrix, applescript, arc, arm, as400cl, ascend, asciidoc, asp, aspect, assembler, ats, autohotkey, autoit, avenue, awk, ballerina, bat, bbcode, bcpl, bibtex, biferno, bison, blitzbasic, bms, bnf, boo, c, carbon, ceylon, charmm, chill, chpl, clean, clearbasic, clipper, clojure, clp, cmake, cobol, coffeescript, coldfusion, conf, cpp2, critic, crk, crystal, cs_block_regex, csharp, css, d, dart, delphi, diff, dockerfile, dts, dylan, ebnf, ebnf2, eiffel, elixir, elm, email, erb, erlang, euphoria, exapunks, excel, express, factor, fame, fasm, felix, fish, fortran77, fortran90, frink, fsharp, fstab, fx, gambas, gdb, gdscript, go, graphviz, haml, hare, haskell, haxe, hcl, html, httpd, hugo, icon, idl, idlang, inc_luatex, informix, ini, innosetup, interlis, io, jam, jasmin, java, javascript, js_regex, json, jsp, jsx, julia, kotlin, ldif, less, lhs, lilypond, limbo, lindenscript, lisp, logtalk, lotos, lotus, lua, luban, makefile, maple, markdown, matlab, maya, mercury, meson, miranda, mod2, mod3, modelica, moon, ms, msl, mssql, mxml, n3, nasal, nbc, nemerle, netrexx, nginx, nice, nim, nix, nsis, nxc, oberon, objc, ocaml, octave, oorexx, org, os, oz, paradox, pas, pdf, perl, php, pike, pl1, plperl, plpython, pltcl, po, polygen, pony, pov, powershell, pro, progress, ps, psl, pure, purebasic, purescript, pyrex, python, q, qmake, qml, qu, r, rebol, rego, rexx, rnc, rpg, rpl, rst, ruby, rust, s, sam, sas, scad, scala, scilab, scss, shellscript, slim, small, smalltalk, sml, snmp, snobol, solidity, spec, spn, sql, squirrel, styl, svg, swift, sybase, tcl, tcsh, terraform, tex, toml, tsql, tsx, ttcn3, txt, typescript, upc, vala, vb, verilog, vhd, vimscript, vue, wat, whiley, wren, xml, xpp, yaiff, yaml, yaml_ansible, yang, zig, znn

For example, to generate a call graph for the FORTRAN 77 program SOLERGY, the following SConstruct file will build the program and generate the RTL (*.expand) file:

Invalid language.

You need to specify a language like this: <source lang="html">...</source>

Supported languages for syntax highlighting:

a4c, abap, abc, abnf, actionscript, ada, agda, alan, algol, ampl, amtrix, applescript, arc, arm, as400cl, ascend, asciidoc, asp, aspect, assembler, ats, autohotkey, autoit, avenue, awk, ballerina, bat, bbcode, bcpl, bibtex, biferno, bison, blitzbasic, bms, bnf, boo, c, carbon, ceylon, charmm, chill, chpl, clean, clearbasic, clipper, clojure, clp, cmake, cobol, coffeescript, coldfusion, conf, cpp2, critic, crk, crystal, cs_block_regex, csharp, css, d, dart, delphi, diff, dockerfile, dts, dylan, ebnf, ebnf2, eiffel, elixir, elm, email, erb, erlang, euphoria, exapunks, excel, express, factor, fame, fasm, felix, fish, fortran77, fortran90, frink, fsharp, fstab, fx, gambas, gdb, gdscript, go, graphviz, haml, hare, haskell, haxe, hcl, html, httpd, hugo, icon, idl, idlang, inc_luatex, informix, ini, innosetup, interlis, io, jam, jasmin, java, javascript, js_regex, json, jsp, jsx, julia, kotlin, ldif, less, lhs, lilypond, limbo, lindenscript, lisp, logtalk, lotos, lotus, lua, luban, makefile, maple, markdown, matlab, maya, mercury, meson, miranda, mod2, mod3, modelica, moon, ms, msl, mssql, mxml, n3, nasal, nbc, nemerle, netrexx, nginx, nice, nim, nix, nsis, nxc, oberon, objc, ocaml, octave, oorexx, org, os, oz, paradox, pas, pdf, perl, php, pike, pl1, plperl, plpython, pltcl, po, polygen, pony, pov, powershell, pro, progress, ps, psl, pure, purebasic, purescript, pyrex, python, q, qmake, qml, qu, r, rebol, rego, rexx, rnc, rpg, rpl, rst, ruby, rust, s, sam, sas, scad, scala, scilab, scss, shellscript, slim, small, smalltalk, sml, snmp, snobol, solidity, spec, spn, sql, squirrel, styl, svg, swift, sybase, tcl, tcsh, terraform, tex, toml, tsql, tsx, ttcn3, txt, typescript, upc, vala, vb, verilog, vhd, vimscript, vue, wat, whiley, wren, xml, xpp, yaiff, yaml, yaml_ansible, yang, zig, znn

Then, use egypt to convert the RTL file into a nice GraphViz diagram:

Invalid language.

You need to specify a language like this: <source lang="html">...</source>

Supported languages for syntax highlighting:

a4c, abap, abc, abnf, actionscript, ada, agda, alan, algol, ampl, amtrix, applescript, arc, arm, as400cl, ascend, asciidoc, asp, aspect, assembler, ats, autohotkey, autoit, avenue, awk, ballerina, bat, bbcode, bcpl, bibtex, biferno, bison, blitzbasic, bms, bnf, boo, c, carbon, ceylon, charmm, chill, chpl, clean, clearbasic, clipper, clojure, clp, cmake, cobol, coffeescript, coldfusion, conf, cpp2, critic, crk, crystal, cs_block_regex, csharp, css, d, dart, delphi, diff, dockerfile, dts, dylan, ebnf, ebnf2, eiffel, elixir, elm, email, erb, erlang, euphoria, exapunks, excel, express, factor, fame, fasm, felix, fish, fortran77, fortran90, frink, fsharp, fstab, fx, gambas, gdb, gdscript, go, graphviz, haml, hare, haskell, haxe, hcl, html, httpd, hugo, icon, idl, idlang, inc_luatex, informix, ini, innosetup, interlis, io, jam, jasmin, java, javascript, js_regex, json, jsp, jsx, julia, kotlin, ldif, less, lhs, lilypond, limbo, lindenscript, lisp, logtalk, lotos, lotus, lua, luban, makefile, maple, markdown, matlab, maya, mercury, meson, miranda, mod2, mod3, modelica, moon, ms, msl, mssql, mxml, n3, nasal, nbc, nemerle, netrexx, nginx, nice, nim, nix, nsis, nxc, oberon, objc, ocaml, octave, oorexx, org, os, oz, paradox, pas, pdf, perl, php, pike, pl1, plperl, plpython, pltcl, po, polygen, pony, pov, powershell, pro, progress, ps, psl, pure, purebasic, purescript, pyrex, python, q, qmake, qml, qu, r, rebol, rego, rexx, rnc, rpg, rpl, rst, ruby, rust, s, sam, sas, scad, scala, scilab, scss, shellscript, slim, small, smalltalk, sml, snmp, snobol, solidity, spec, spn, sql, squirrel, styl, svg, swift, sybase, tcl, tcsh, terraform, tex, toml, tsql, tsx, ttcn3, txt, typescript, upc, vala, vb, verilog, vhd, vimscript, vue, wat, whiley, wren, xml, xpp, yaiff, yaml, yaml_ansible, yang, zig, znn

The result is a nice callgraph like so:

Callgraph for the SOLERGY program, written in FORTRAN 77

You can use exactly the same approach for C programs. In the sample SConstruct file, just change FORTRANFLAGS to CFLAGS and change the name of the source code file accordingly.