[clang-tidy] readability-misplaced-array-index: add new check that warns when array index is misplaced.

Reviewers: alexfh

Differential Revision: https://reviews.llvm.org/D21134

llvm-svn: 281206

1 files changed, 34 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/readability-misplaced-array-index.cpp b/clang-tools-extra/test/clang-tidy/readability-misplaced-array-index.cpp
new file mode 100644
index 00000000000..43dd4583d5e
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/readability-misplaced-array-index.cpp
@@ -0,0 +1,34 @@
+// RUN: %check_clang_tidy %s readability-misplaced-array-index %t
+
+#define ABC  "abc"
+
+struct XY { int *X; int *Y; };
+
+void dostuff(int);
+
+void unusualSyntax(int *P1, struct XY *P2) {
+  10[P1] = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: confusing array subscript expression, usually the index is inside the []
+  // CHECK-FIXES: P1[10] = 0;
+
+  10[P2->X] = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: confusing array subscript expression
+  // CHECK-FIXES: P2->X[10] = 0;
+
+  dostuff(1["abc"]);
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: confusing array subscript expression
+  // CHECK-FIXES:  dostuff("abc"[1]);
+
+  dostuff(1[ABC]);
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: confusing array subscript expression
+  // CHECK-FIXES:  dostuff(ABC[1]);
+
+  dostuff(0[0 + ABC]);
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: confusing array subscript expression
+  // CHECK-FIXES:  dostuff(0[0 + ABC]);
+  // No fixit. Probably the code should be ABC[0]
+}
+
+void normalSyntax(int *X) {
+  X[10] = 0;
+}