Guidelines: Guidelines in use of #ifdef in C/C++ programs.
Projects: GCC, Gnome, Hurd, Gimp, Inkscape, Linux, Libreoffice, Firefox, Wireshark
Bugs/Guidelines description by colors:

• Guideline #1:Verify if value of artefact (variable or function) in some feature was changed and if compatible with your type.
  Example:#ifdef A x = 3; #endif x = 4;
• Guideline #2:Verify if condicional block is inside or outside in feature.
  Example: if { #ifdef A #endif } else { #ifdef A #endif }
• Guideline #3:Verify if artefact (variable or function) is inside in optional or mandatory feature which are accessed by other feature but without dependencies.
  Example: #ifdef A int x; #endif #ifdef B x #endif
• Guideline #4:Verify if variable was used before inicialize in some feature.
  Example: #ifdef A int x; #endif x
• Guideline #5:Verify if variable has same name in some feature.
  Example: #ifdef A int x; #endif #ifdef B int x #endif
• Guideline #6:Verify if artefacts are without use in some feature.
  Example: #ifdef A int x; char y #endif