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-rw-r--r--clang/test/Sema/self-comparison.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/clang/test/Sema/self-comparison.c b/clang/test/Sema/self-comparison.c
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+++ b/clang/test/Sema/self-comparison.c
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+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+int foo(int x) {
+ return x == x; // expected-warning {{self-comparison always evaluates to true}}
+}
+
+int foo2(int x) {
+ return (x) != (((x))); // expected-warning {{self-comparison always evaluates to false}}
+}
+
+void foo3(short s, short t) {
+ if (s == s) {} // expected-warning {{self-comparison always evaluates to true}}
+ if (s == t) {} // no-warning
+}
+
+void foo4(void* v, void* w) {
+ if (v == v) {} // expected-warning {{self-comparison always evaluates to true}}
+ if (v == w) {} // no-warning
+}
+
+int qux(int x) {
+ return x < x; // expected-warning {{self-comparison}}
+}
+
+int qux2(int x) {
+ return x > x; // expected-warning {{self-comparison}}
+}
+
+int bar(float x) {
+ return x == x; // no-warning
+}
+
+int bar2(float x) {
+ return x != x; // no-warning
+}
+
+#define IS_THE_ANSWER(x) (x == 42)
+
+int macro_comparison() {
+ return IS_THE_ANSWER(42);
+}
+
+// Don't complain in unevaluated contexts.
+int compare_sizeof(int x) {
+ return sizeof(x == x); // no-warning
+}
+
+int array_comparisons() {
+ int array1[2];
+ int array2[2];
+
+ //
+ // compare same array
+ //
+ return array1 == array1; // expected-warning{{self-comparison always evaluates to true}}
+ return array1 != array1; // expected-warning{{self-comparison always evaluates to false}}
+ return array1 < array1; // expected-warning{{self-comparison always evaluates to false}}
+ return array1 <= array1; // expected-warning{{self-comparison always evaluates to true}}
+ return array1 > array1; // expected-warning{{self-comparison always evaluates to false}}
+ return array1 >= array1; // expected-warning{{self-comparison always evaluates to true}}
+
+ //
+ // compare differrent arrays
+ //
+ return array1 == array2; // expected-warning{{array comparison always evaluates to false}}
+ return array1 != array2; // expected-warning{{array comparison always evaluates to true}}
+
+ //
+ // we don't know what these are going to be
+ //
+ return array1 < array2; // expected-warning{{array comparison always evaluates to a constant}}
+ return array1 <= array2; // expected-warning{{array comparison always evaluates to a constant}}
+ return array1 > array2; // expected-warning{{array comparison always evaluates to a constant}}
+ return array1 >= array2; // expected-warning{{array comparison always evaluates to a constant}}
+
+}
+
+// Don't issue a warning when either the left or right side of the comparison
+// results from a macro expansion. <rdar://problem/8435950>
+#define R8435950_A i
+#define R8435950_B i
+
+int R8435950(int i) {
+ if (R8435950_A == R8435950_B) // no-warning
+ return 0;
+ return 1;
+}
+