[PATCH] D87683: [clang-tidy] Crash fix for bugprone-misplaced-pointer-arithmetic-in-alloc

[Balogh, Ádám via Phabricator via cfe-commits]

baloghadamsoftware created this revision.
baloghadamsoftware added reviewers: gribozavr2, aaron.ballman.
baloghadamsoftware added a project: clang-tools-extra.
Herald added subscribers: martong, steakhal, gamesh411, Szelethus, dkrupp, rnkovacs, xazax.hun, whisperity.
Herald added a project: clang.
baloghadamsoftware requested review of this revision.

Placement new operators on non-object types cause crash in `bugprone-misplaced-pointer-arithmetic-in-alloc`. This patch fixes this issue.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D87683

Files:
  clang-tools-extra/clang-tidy/bugprone/MisplacedPointerArithmeticInAllocCheck.cpp
  clang-tools-extra/test/clang-tidy/checkers/bugprone-misplaced-pointer-arithmetic-in-alloc.cpp


Index: clang-tools-extra/test/clang-tidy/checkers/bugprone-misplaced-pointer-arithmetic-in-alloc.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/checkers/bugprone-misplaced-pointer-arithmetic-in-alloc.cpp
+++ clang-tools-extra/test/clang-tidy/checkers/bugprone-misplaced-pointer-arithmetic-in-alloc.cpp
@@ -51,3 +51,10 @@
   // CHECK-FIXES: p = new char[n - m] + 10;
   // FIXME: should be p = new char[n - m + 10];
 }
+
+void* operator new(unsigned long, void*);
+
+void placement_new_ptr(void *buf, C *old) {
+  C **p = new (buf) C*(old) + 1;
+  // CHECK-MESSAGES-NOT: :[[@LINE-1]]:11: warning: arithmetic operation is applied to the result of operator new() instead of its size-like argument
+}
Index: clang-tools-extra/clang-tidy/bugprone/MisplacedPointerArithmeticInAllocCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/bugprone/MisplacedPointerArithmeticInAllocCheck.cpp
+++ clang-tools-extra/clang-tidy/bugprone/MisplacedPointerArithmeticInAllocCheck.cpp
@@ -77,9 +77,9 @@
       CallName = "operator new[]";
     } else {
       const auto *CtrE = New->getConstructExpr();
-      if (!CtrE->getArg(CtrE->getNumArgs() - 1)
-               ->getType()
-               ->isIntegralOrEnumerationType())
+      if (!CtrE || !CtrE->getArg(CtrE->getNumArgs() - 1)
+                                     ->getType()
+                                     ->isIntegralOrEnumerationType())
         return;
       CallName = "operator new";
     }


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