clang/test/Analysis/copypaste/macro-complexity.cpp

   1 // RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=alpha.clone.CloneChecker -analyzer-config alpha.clone.CloneChecker:MinimumCloneComplexity=10 -verify %s
   2
   3 // Tests that the complexity value of a macro expansion is about the same as
   4 // the complexity value of a normal function call and the macro body doesn't
   5 // influence the complexity. See the CloneSignature class in CloneDetection.h
   6 // for more information about complexity values of clones.
   7
   8 #define MACRO_FOO(a, b) a > b ? -a * a : -b * b;
   9
  10 // First, manually apply MACRO_FOO and see if the code gets detected as a clone.
  11 // This confirms that with the current configuration the macro body would be
  12 // considered large enough to pass the MinimumCloneComplexity constraint.
  13
  14 int manualMacro(int a, int b) { // expected-warning{{Duplicate code detected}}
  15   return a > b ? -a * a : -b * b;
  16 }
  17
  18 int manualMacroClone(int a, int b) { // expected-note{{Similar code here}}
  19   return a > b ? -a * a : -b * b;
  20 }
  21
  22 // Now we actually use the macro to generate the same AST as above. They
  23 // shouldn't be reported because the macros only slightly increase the complexity
  24 // value and the resulting code will never pass the MinimumCloneComplexity
  25 // constraint.
  26
  27 int macro(int a, int b) {
  28   return MACRO_FOO(a, b);
  29 }
  30
  31 int macroClone(int a, int b) {
  32   return MACRO_FOO(a, b);
  33 }
  34
  35 // So far we only tested that macros increase the complexity by a lesser amount
  36 // than normal code. We also need to be sure this amount is not zero because
  37 // we otherwise macro code would be 'invisible' for the CloneDetector.
  38 // This tests that it is possible to increase the reach the minimum complexity
  39 // by only using macros. This is only possible if the complexity value is bigger
  40 // than zero.
  41
  42 #define NEG(A) -(A)
  43
  44 int nestedMacros() { // expected-warning{{Duplicate code detected}}
  45   return NEG(NEG(NEG(NEG(NEG(NEG(NEG(NEG(NEG(NEG(1))))))))));
  46 }
  47
  48 int nestedMacrosClone() { // expected-note{{Similar code here}}
  49   return NEG(NEG(NEG(NEG(NEG(NEG(NEG(NEG(NEG(NEG(1))))))))));
  50 }