clang/test/Analysis/copypaste/suspicious-clones.cpp

   1 // RUN: %clang_analyze_cc1 -verify %s \
   2 // RUN:   -analyzer-checker=alpha.clone.CloneChecker \
   3 // RUN:   -analyzer-config alpha.clone.CloneChecker:ReportNormalClones=false \
   4 // RUN:   -analyzer-config alpha.clone.CloneChecker:MinimumCloneComplexity=10
   5
   6 // Tests finding a suspicious clone that references local variables.
   7
   8 void log();
   9
  10 int max(int a, int b) {
  11   log();
  12   if (a > b)
  13     return a;
  14   return b; // expected-note{{Similar code using 'b' here}}
  15 }
  16
  17 int maxClone(int x, int y, int z) {
  18   log();
  19   if (x > y)
  20     return x;
  21   return z; // expected-warning{{Potential copy-paste error; did you really mean to use 'z' here?}}
  22 }
  23
  24 // Tests finding a suspicious clone that references global variables.
  25
  26 struct mutex {
  27   bool try_lock();
  28   void unlock();
  29 };
  30
  31 mutex m1;
  32 mutex m2;
  33 int i;
  34
  35 void busyIncrement() {
  36   while (true) {
  37     if (m1.try_lock()) {
  38       ++i;
  39       m1.unlock(); // expected-note{{Similar code using 'm1' here}}
  40       if (i > 1000) {
  41         return;
  42       }
  43     }
  44   }
  45 }
  46
  47 void faultyBusyIncrement() {
  48   while (true) {
  49     if (m1.try_lock()) {
  50       ++i;
  51       m2.unlock();  // expected-warning{{Potential copy-paste error; did you really mean to use 'm2' here?}}
  52       if (i > 1000) {
  53         return;
  54       }
  55     }
  56   }
  57 }
  58
  59 // Tests that we provide two suggestions in cases where two fixes are possible.
  60
  61 int foo(int a, int b, int c) {
  62   a += b + c;
  63   b /= a + b;
  64   c -= b * a; // expected-warning{{Potential copy-paste error; did you really mean to use 'b' here?}}
  65   return c;
  66 }
  67
  68 int fooClone(int a, int b, int c) {
  69   a += b + c;
  70   b /= a + b;
  71   c -= a * a; // expected-note{{Similar code using 'a' here}}
  72   return c;
  73 }
  74
  75
  76 // Tests that for clone groups with a many possible suspicious clone pairs, at
  77 // most one warning per clone group is generated and every relevant clone is
  78 // reported through either a warning or a note.
  79
  80 long bar1(long a, long b, long c, long d) {
  81   c = a - b;
  82   c = c / d * a;
  83   d = b * b - c; // expected-warning{{Potential copy-paste error; did you really mean to use 'b' here?}}
  84   return d;
  85 }
  86
  87 long bar2(long a, long b, long c, long d) {
  88   c = a - b;
  89   c = c / d * a;
  90   d = c * b - c; // expected-note{{Similar code using 'c' here}} \
  91                  // expected-warning{{Potential copy-paste error; did you really mean to use 'c' here?}}
  92   return d;
  93 }
  94
  95 long bar3(long a, long b, long c, long d) {
  96   c = a - b;
  97   c = c / d * a;
  98   d = a * b - c; // expected-note{{Similar code using 'a' here}}
  99   return d;
 100 }