[Clang-tidy] check for malloc, realloc and free calls

Summary:
This checker flags the use of C-style memory management functionality and notes about modern alternatives.
In an earlier revision it tried to autofix some kind of patterns, but that was a bad idea. Since memory management can be so widespread in a program, manual updating is most likely necessary.
Maybe for special cases, there could be later additions to this basic checker.

This is the first checker I wrote and I never did something with clang (only compiling programs). So whenever I missed conventions or did plain retarded stuff, feel free to point it out! I am willing to fix them and write a better checker.

I hope the patch does work, I never did this either. On a testapply in my repository it did, but I am pretty unconfident in my patching skills :)

Reviewers: aaron.ballman, hokein, alexfh, malcolm.parsons

Subscribers: cfe-commits, JDevlieghere, nemanjai, Eugene.Zelenko, Prazek, mgorny, modocache

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D26167

Patch by Jonas Toth!

llvm-svn: 289546

1 files changed, 42 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/cppcoreguidelines-no-malloc.cpp b/clang-tools-extra/test/clang-tidy/cppcoreguidelines-no-malloc.cpp
new file mode 100644
index 00000000000..8f840242a46
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/cppcoreguidelines-no-malloc.cpp
@@ -0,0 +1,42 @@
+// RUN: %check_clang_tidy %s cppcoreguidelines-no-malloc %t
+
+using size_t = unsigned long;
+
+void *malloc(size_t size);
+void *calloc(size_t num, size_t size);
+void *realloc(void *ptr, size_t size);
+void free(void *ptr);
+
+void malloced_array() {
+  int *array0 = (int *)malloc(sizeof(int) * 20);
+  // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: do not manage memory manually; consider a container or a smart pointer [cppcoreguidelines-no-malloc]
+
+  int *zeroed = (int *)calloc(20, sizeof(int));
+  // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: do not manage memory manually; consider a container or a smart pointer [cppcoreguidelines-no-malloc]
+
+  // reallocation memory, std::vector shall be used
+  char *realloced = (char *)realloc(array0, 50 * sizeof(int));
+  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: do not manage memory manually; consider std::vector or std::string [cppcoreguidelines-no-malloc]
+
+  // freeing memory the bad way
+  free(realloced);
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not manage memory manually; use RAII [cppcoreguidelines-no-malloc]
+
+  // check if a call to malloc as function argument is found as well
+  free(malloc(20));
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not manage memory manually; use RAII [cppcoreguidelines-no-malloc]
+  // CHECK-MESSAGES: :[[@LINE-2]]:8: warning: do not manage memory manually; consider a container or a smart pointer [cppcoreguidelines-no-malloc]
+}
+
+/// newing an array is still not good, but not relevant to this checker
+void newed_array() {
+  int *new_array = new int[10]; // OK(1)
+}
+
+void arbitrary_call() {
+  // we dont want every function to raise the warning even if malloc is in the name
+  malloced_array(); // OK(2)
+
+  // completly unrelated function call to malloc
+  newed_array(); // OK(3)
+}