1 files changed, 106 insertions, 0 deletions
diff --git a/clang-tools-extra/test/clang-tidy/bugprone-macro-repeated-side-effects.c b/clang-tools-extra/test/clang-tidy/bugprone-macro-repeated-side-effects.c
new file mode 100644
index 00000000000..bcea47a4c11
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/bugprone-macro-repeated-side-effects.c
@@ -0,0 +1,106 @@
+// RUN: %check_clang_tidy %s bugprone-macro-repeated-side-effects %t
+
+#define badA(x,y)  ((x)+((x)+(y))+(y))
+void bad(int ret, int a, int b) {
+  ret = badA(a++, b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: side effects in the 1st macro argument 'x' are repeated in macro expansion [bugprone-macro-repeated-side-effects]
+  ret = badA(++a, b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: side effects in the 1st macro argument 'x'
+  ret = badA(a--, b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: side effects in the 1st macro argument 'x'
+  ret = badA(--a, b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: side effects in the 1st macro argument 'x'
+  ret = badA(a, b++);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: side effects in the 2nd macro argument 'y'
+  ret = badA(a, ++b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: side effects in the 2nd macro argument 'y'
+  ret = badA(a, b--);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: side effects in the 2nd macro argument 'y'
+  ret = badA(a, --b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: side effects in the 2nd macro argument 'y'
+}
+
+
+#define MIN(A,B)     ((A) < (B) ? (A) : (B))                        // single ?:
+#define LIMIT(X,A,B) ((X) < (A) ? (A) : ((X) > (B) ? (B) : (X)))    // two ?:
+void question(int x) {
+  MIN(x++, 12);
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: side effects in the 1st macro argument 'A'
+  MIN(34, x++);
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: side effects in the 2nd macro argument 'B'
+  LIMIT(x++, 0, 100);
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: side effects in the 1st macro argument 'X'
+  LIMIT(20, x++, 100);
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: side effects in the 2nd macro argument 'A'
+  LIMIT(20, 0, x++);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: side effects in the 3rd macro argument 'B'
+}
+
+// False positive: Repeated side effects is intentional.
+// It is hard to know when it's done by intention so right now we warn.
+#define UNROLL(A)    {A A}
+void fp1(int i) {
+  UNROLL({ i++; });
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: side effects in the 1st macro argument 'A'
+}
+
+// Do not produce a false positive on a strchr() macro. Explanation; Currently the '?'
+// triggers the test to bail out, because it cannot evaluate __builtin_constant_p(c).
+#  define strchrs(s, c) \
+  (__extension__ (__builtin_constant_p (c) && !__builtin_constant_p (s)	      \
+		  && (c) == '\0'					      \
+		  ? (char *) __rawmemchr (s, c)				      \
+		  : __builtin_strchr (s, c)))
+char* __rawmemchr(char* a, char b) {
+  return a;
+}
+void pass(char* pstr, char ch) {
+  strchrs(pstr, ch++); // No error.
+}
+
+// Check large arguments (t=20, u=21).
+#define largeA(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, x, y, z) \
+  ((a) + (a) + (b) + (b) + (c) + (c) + (d) + (d) + (e) + (e) + (f) + (f) + (g) + (g) +    \
+   (h) + (h) + (i) + (i) + (j) + (j) + (k) + (k) + (l) + (l) + (m) + (m) + (n) + (n) +    \
+   (o) + (o) + (p) + (p) + (q) + (q) + (r) + (r) + (s) + (s) + (t) + (t) + (u) + (u) +    \
+   (v) + (v) + (x) + (x) + (y) + (y) + (z) + (z))
+void large(int a) {
+  largeA(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, a++, 0, 0, 0, 0, 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:64: warning: side effects in the 19th macro argument 's'
+  largeA(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, a++, 0, 0, 0, 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:67: warning: side effects in the 20th macro argument 't'
+  largeA(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, a++, 0, 0, 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:70: warning: side effects in the 21st macro argument 'u'
+}
+
+// Passing macro argument as argument to __builtin_constant_p and macros.
+#define builtinbad(x)      (__builtin_constant_p(x) + (x) + (x))
+#define builtingood1(x)    (__builtin_constant_p(x) + (x))
+#define builtingood2(x)    ((__builtin_constant_p(x) && (x)) || (x))
+#define macrobad(x)        (builtingood1(x) + (x) + (x))
+#define macrogood(x)       (builtingood1(x) + (x))
+void builtins(int ret, int a) {
+  ret += builtinbad(a++);
+  // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: side effects in the 1st macro argument 'x'
+
+  ret += builtingood1(a++);
+  ret += builtingood2(a++);
+
+  ret += macrobad(a++);
+  // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: side effects in the 1st macro argument 'x'
+
+  ret += macrogood(a++);
+}
+
+// Bail out for conditionals.
+#define condB(x,y)  if(x) {x=y;} else {x=y + 1;}
+void conditionals(int a, int b)
+{
+  condB(a, b++);
+}
+
+void log(const char *s, int v);
+#define LOG(val) log(#val, (val))
+void test_log(int a) {
+  LOG(a++);
+}