instrumentation: include functions with specific calls (#202)

* instrumentation: include functions with specific calls

Add the option `--caller-include <regex>` or environment variable
`OMNITRACE_REGEX_CALLER_INCLUDE` to instrument functions which contain
call to a set of functions, E.g. `--caller-include foo` instruments any
function which calls `foo`.

* Serialize caller include information

* Add test for caller include

* Tweak to the caller include test

- tweak environment
- tweak pass regexes

* Set rewrite caller example to debug

, to avoid optimizing out the call expressions that it relies on.

Co-authored-by: Jonathan R. Madsen <jonathanrmadsen@gmail.com>

source/bin/omnitrace/module_function.cpp

@@ -333,7 +333,7 @@ module_function::is_user_included() const
         }
     }
 
-    return false;
+    return contains_user_callsite();
 }
 
 bool
@@ -534,6 +534,27 @@ module_function::contains_dynamic_callsites() const
     return false;
 }
 
+bool
+module_function::contains_user_callsite() const
+{
+    if(caller_include.empty()) return false;
+
+    bpvector_t<BPatch_point*> call_points;
+    function->getCallPoints(call_points);
+    for(const auto& call_point : call_points)
+    {
+        if(check_regex_restrictions(
+               std::string(get_name(call_point->getCalledFunction())), caller_include))
+        {
+            messages.emplace_back(2, "Forcing", "function", "caller-include-regex",
+                                  function_name);
+            return true;
+        }
+    }
+
+    return false;
+}
+
 bool
 module_function::is_dynamic_callsite_forced() const
 {