[PATCH] D97512: [clang] removes check against integral-to-pointer conversion...

[Christopher Di Bella via Phabricator via cfe-commits]

cjdb created this revision.
cjdb added a reviewer: aaron.ballman.
cjdb requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

... unless it's a literal


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D97512

Files:
  clang/lib/Sema/SemaChecking.cpp
  clang/test/Analysis/free.c
  clang/test/Analysis/free.cpp


Index: clang/test/Analysis/free.cpp
===================================================================
--- clang/test/Analysis/free.cpp
+++ clang/test/Analysis/free.cpp
@@ -208,3 +208,15 @@
   // Unknown value
   std::free(x[offset]); // no-warning
 }
+
+struct S {
+  const char* p;
+};
+
+void t18a (S s) {
+  free((void*)(unsigned long long)s.p); // no warning
+}
+
+void t18b (S s) {
+  std::free((void*)(unsigned long long)s.p); // no warning
+}
Index: clang/test/Analysis/free.c
===================================================================
--- clang/test/Analysis/free.c
+++ clang/test/Analysis/free.c
@@ -108,3 +108,11 @@
   // expected-warning at -1{{Argument to free() is the address of the function 'iptr', which is not memory allocated by malloc()}}
   // expected-warning at -2{{attempt to call free on non-heap object 'iptr'}}
 }
+
+struct S {
+  const char* p;
+};
+
+void t18 (struct S s) {
+  free((void*)(unsigned long long)s.p); // no warning
+}
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -10316,11 +10316,18 @@
                             const CastExpr *Cast) {
   SmallString<128> SizeString;
   llvm::raw_svector_ostream OS(SizeString);
+
+  const clang::CastKind Kind = Cast->getCastKind();
+  if (Kind == clang::CK_BitCast &&
+      !Cast->getSubExpr()->getType()->isFunctionPointerType())
+    return;
+  if (Kind == clang::CK_IntegralToPointer &&
+      !isa<IntegerLiteral>(
+          Cast->getSubExpr()->IgnoreImplicitAsWritten()->IgnoreParens()))
+    return;
+
   switch (Cast->getCastKind()) {
   case clang::CK_BitCast:
-    if (!Cast->getSubExpr()->getType()->isFunctionPointerType())
-      return;
-    [[clang::fallthrough]];
   case clang::CK_IntegralToPointer:
   case clang::CK_FunctionToPointerDecay:
     OS << '\'';


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