[analysis-scripts] add test for estimate-difficulty

tests/fc_script/estimate_difficulty.i

+/* run.config
+   NOFRAMAC: testing frama-c-script, not frama-c itself
+   EXECNOW: LOG @PTEST_NAME@.res LOG @PTEST_NAME@.err PTESTS_TESTING=1 %{bin:frama-c-script} estimate-difficulty @PTEST_FILE@ > @PTEST_NAME@.res 2> @PTEST_NAME@.err
+*/
+
+// these includes are not actually used by the compiler
+// (this is a preprocessed file), but analyzed by the script
+#include <sys/socket.h>
+# include <complex.h>
+  #	include <langinfo.h>
+#include <sys/socket.h>
+
+void g() {
+  int g = 42;
+}
+
+void f() {
+  if (v) f();
+  else g();
+}
+
+int main() {
+  va_arg(); // no warning: it is a macro, not a function
+  setjmp(); // warning: problematic
+  strlen(); // no warning
+  ccosl(); // warning: neither code nor spec
+  dprintf(); // no warning: neither code nor spec, but handled by Variadic
+}

tests/fc_script/oracle/estimate_difficulty.res

+Building callgraph...
+Computing data about libc/POSIX functions...
+[recursion] found recursive cycle near estimate_difficulty.i:18: f -> f
+Estimating difficulty for 7 function calls...
+- warning: ccosl (POSIX) has neither code nor spec in Frama-C's libc
+- warning: setjmp (POSIX) is known to be problematic for code analysis
+Function-related warnings: 2
+Estimating difficulty for 3 '#include <header>' directives...
+- WARNING: included header <complex.h> is explicitly unsupported by Frama-C
+- warning: included header <langinfo.h> not currently included in Frama-C's libc
+Header-related warnings: 2

tests/fc_script/oracle/find_fun1.res

-Looking for 'main2' inside 14 file(s)...
+Looking for 'main2' inside 15 file(s)...
 Possible declarations for function 'main2' in the following file(s):
   for-find-fun.c
 Possible definitions for function 'main2' in the following file(s):

tests/fc_script/oracle/find_fun2.res

-Looking for 'main3' inside 14 file(s)...
+Looking for 'main3' inside 15 file(s)...
 Possible declarations for function 'main3' in the following file(s):
   for-find-fun2.c
 Possible definitions for function 'main3' in the following file(s):

tests/fc_script/oracle/find_fun3.res

-Looking for 'false_positive' inside 14 file(s)...
+Looking for 'false_positive' inside 15 file(s)...
 No declaration/definition found for function 'false_positive'