[clang-tidy] Misplaced Operator in Strlen in Alloc

A possible error is to write `malloc(strlen(s+1))` instead of
`malloc(strlen(s)+1)`. Unfortunately the former is also valid syntactically,
but allocates less memory by two bytes (if `s` is at least one character long,
undefined behavior otherwise) which may result in overflow cases. This check
detects such cases and also suggests the fix for them.

Fix for r318906, forgot to add new files.

llvm-svn: 318907

1 files changed, 33 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/bugprone-misplaced-operator-in-strlen-in-alloc.cpp b/clang-tools-extra/test/clang-tidy/bugprone-misplaced-operator-in-strlen-in-alloc.cpp
new file mode 100644
index 00000000000..406b04348af
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/bugprone-misplaced-operator-in-strlen-in-alloc.cpp
@@ -0,0 +1,33 @@
+// RUN: %check_clang_tidy %s bugprone-misplaced-operator-in-strlen-in-alloc %t
+
+namespace std {
+typedef __typeof(sizeof(int)) size_t;
+void *malloc(size_t);
+
+size_t strlen(const char *);
+} // namespace std
+
+namespace non_std {
+typedef __typeof(sizeof(int)) size_t;
+void *malloc(size_t);
+
+size_t strlen(const char *);
+} // namespace non_std
+
+void bad_std_malloc_std_strlen(char *name) {
+  char *new_name = (char *)std::malloc(std::strlen(name + 1));
+  // CHECK-MESSAGES: :[[@LINE-1]]:28: warning: addition operator is applied to the argument of strlen
+  // CHECK-FIXES: {{^  char \*new_name = \(char \*\)std::malloc\(}}std::strlen(name) + 1{{\);$}}
+}
+
+void ignore_non_std_malloc_std_strlen(char *name) {
+  char *new_name = (char *)non_std::malloc(std::strlen(name + 1));
+  // CHECK-MESSAGES-NOT: :[[@LINE-1]]:28: warning: addition operator is applied to the argument of strlen
+  // Ignore functions of the malloc family in custom namespaces
+}
+
+void ignore_std_malloc_non_std_strlen(char *name) {
+  char *new_name = (char *)std::malloc(non_std::strlen(name + 1));
+  // CHECK-MESSAGES-NOT: :[[@LINE-1]]:28: warning: addition operator is applied to the argument of strlen
+  // Ignore functions of the strlen family in custom namespaces
+}