[PATCH] D131926: [clang-tidy] Fix for bugprone-sizeof-expression PR57167

[Chris Hamilton via Phabricator via cfe-commits]

chrish_ericsson_atx created this revision.
chrish_ericsson_atx added reviewers: mizvekov, baloghadamsoftware, njames93, cfe-commits.
Herald added subscribers: carlosgalvezp, rnkovacs, xazax.hun.
Herald added a project: All.
chrish_ericsson_atx requested review of this revision.
Herald added a project: clang-tools-extra.

This addresses a change in behavior of the bugprone-sizeof-expression
checker after upstream commit 15f3cd6bfc6 <https://reviews.llvm.org/rG15f3cd6bfc670ba6106184a903eb04be059e5977>, which cleaned up
ElaboratedType sugaring in the AST.  This restores (mostly) the
beahvior of the checker prior to that commit, which may or may not have
been consistent with the intent of the checker, but at least gave a
tolerable level of what users would consider false positives.

      

Bug: https://github.com/llvm/llvm-project/issues/57167


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D131926

Files:
  clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
  clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression-2.c
  clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression.cpp


Index: clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression.cpp
+++ clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression.cpp
@@ -233,9 +233,7 @@
   sum += sizeof(&S);
   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
   sum += sizeof(MyStruct*);
-  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
   sum += sizeof(PMyStruct);
-  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
   sum += sizeof(PS);
   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
   sum += sizeof(PS2);
Index: clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression-2.c
===================================================================
--- /dev/null
+++ clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression-2.c
@@ -0,0 +1,62 @@
+// RUN: %check_clang_tidy %s bugprone-sizeof-expression %t -- --
+// RUN: %check_clang_tidy %s bugprone-sizeof-expression %t -- -- -x c++
+
+#ifdef __cplusplus
+#define STRKWD
+#else
+#define STRKWD struct
+#endif
+
+int Test5() {
+  typedef int Array10[10];
+
+  struct MyStruct {
+    Array10 arr;
+    Array10* ptr;
+  };
+
+  typedef struct TypedefStruct {
+    Array10 arr;
+    Array10* ptr;
+  } TypedefStruct;
+
+  typedef const STRKWD MyStruct TMyStruct;
+  typedef const STRKWD MyStruct *PMyStruct;
+  typedef TMyStruct *PMyStruct2;
+  typedef const TypedefStruct *PTTStruct;
+
+  STRKWD MyStruct S;
+  TypedefStruct TS;
+  PMyStruct PS;
+  PMyStruct2 PS2;
+  Array10 A10;
+  PTTStruct PTTS;
+
+  int sum = 0;
+  sum += sizeof(&S);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(__typeof(&S));
+  sum += sizeof(&TS);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(__typeof(&TS));
+  sum += sizeof(STRKWD MyStruct*);
+  sum += sizeof(__typeof(STRKWD MyStruct*));
+  sum += sizeof(TypedefStruct*);
+  sum += sizeof(__typeof(TypedefStruct*));
+  sum += sizeof(PTTS);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(PMyStruct);
+  sum += sizeof(PS);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(PS2);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+  sum += sizeof(&A10);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(A*)'; pointer to aggregate
+
+#ifdef __cplusplus
+  MyStruct &rS = S;
+  sum += sizeof(rS); // same as sizeof(S), not a pointer.  So should not warn.
+#endif
+
+  return sum;
+}
\ No newline at end of file
Index: clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
+++ clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
@@ -148,7 +148,7 @@
       hasOperatorName("&"), hasUnaryOperand(ignoringParenImpCasts(
                                 hasType(hasCanonicalType(recordType())))));
   const auto PointerToStructType = hasUnqualifiedDesugaredType(
-      pointerType(pointee(hasCanonicalType(recordType()))));
+      pointerType(pointee(recordType())));
   const auto PointerToStructExpr = ignoringParenImpCasts(expr(
       hasType(hasCanonicalType(PointerToStructType)), unless(cxxThisExpr())));
 


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