[clang] 2cea4c2 - Do not suggest taking the address of a const pointer to get void*

[David Blaikie via cfe-commits]

Author: Alexey Kreshchuk
Date: 2022-11-23T18:43:06Z
New Revision: 2cea4c239570c37f46ad0003b3d41d9473aca60f

URL: https://github.com/llvm/llvm-project/commit/2cea4c239570c37f46ad0003b3d41d9473aca60f
DIFF: https://github.com/llvm/llvm-project/commit/2cea4c239570c37f46ad0003b3d41d9473aca60f.diff

LOG: Do not suggest taking the address of a const pointer to get void*

It's more likely the user needs a const cast, but probably not sure
enough that we should suggest that either - so err on the side of
caution and offer no suggestion.

Fixes pr58958

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D138426

Added: 
    

Modified: 
    clang/lib/Sema/SemaFixItUtils.cpp
    clang/test/FixIt/fixit-function-call.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaFixItUtils.cpp b/clang/lib/Sema/SemaFixItUtils.cpp
index 2910a56f866bb..2c85a53194301 100644
--- a/clang/lib/Sema/SemaFixItUtils.cpp
+++ b/clang/lib/Sema/SemaFixItUtils.cpp
@@ -124,7 +124,7 @@ bool ConversionFixItGenerator::tryToFixConversion(const Expr *FullExpr,
 
   // Check if the pointer to the argument needs to be passed:
   //   (type -> type *) or (type & -> type *).
-  if (isa<PointerType>(ToQTy)) {
+  if (const auto *ToPtrTy = dyn_cast<PointerType>(ToQTy)) {
     bool CanConvert = false;
     OverloadFixItKind FixKind = OFIK_TakeAddress;
 
@@ -132,6 +132,10 @@ bool ConversionFixItGenerator::tryToFixConversion(const Expr *FullExpr,
     if (!Expr->isLValue() || Expr->getObjectKind() != OK_Ordinary)
       return false;
 
+    // Do no take address of const pointer to get void*
+    if (isa<PointerType>(FromQTy) && ToPtrTy->isVoidPointerType())
+      return false;
+
     CanConvert = CompareTypes(S.Context.getPointerType(FromQTy), ToQTy, S,
                               Begin, VK_PRValue);
     if (CanConvert) {

diff  --git a/clang/test/FixIt/fixit-function-call.cpp b/clang/test/FixIt/fixit-function-call.cpp
index 273e4a41ec8dd..88f636ea5859d 100644
--- a/clang/test/FixIt/fixit-function-call.cpp
+++ b/clang/test/FixIt/fixit-function-call.cpp
@@ -115,4 +115,25 @@ void dbcaller(A *ptra, B *ptrb, C &c, B &refb) {
   u(c);
 }
 
+void accept_void(void*);
+
+void issue58958(const char* a, volatile char * v, const volatile char * cv) {
+// CHECK: no matching function for call to 'accept_void'
+// CHECK-NOT: take the address of the argument with &
+    accept_void(a);
+// CHECK: no matching function for call to 'accept_void'
+// CHECK-NOT: take the address of the argument with &
+    accept_void(v);
+// CHECK: no matching function for call to 'accept_void'
+// CHECK-NOT: take the address of the argument with &
+    accept_void(cv);
+    char b;
+// CHECK: no matching function for call to 'accept_void'
+// CHECK: take the address of the argument with &
+    accept_void(b);
+// CHECK-NOT: no matching function for call to 'accept_void'
+// CHECK-NOT: take the address of the argument with &
+    accept_void(&b);
+}
+
 // CHECK: errors generated