[PATCH] D58145: [Sema] Fix a bogus -Wconversion warning

[Erik Pilkington via Phabricator via cfe-commits]

erik.pilkington created this revision.
erik.pilkington added reviewers: rjmccall, rsmith, nickdesaulniers.
Herald added subscribers: dexonsmith, jkorous.
Herald added a project: clang.

DiagnoseFloatingImpCast expects an integer type, but the changes introduced in D50467 <https://reviews.llvm.org/D50467> caused us to warn on any builtin type, even pseudo-object type. This lead to us warning in this property expression's syntactic form. Its not clear to me that we should even be analyzing the syntactic form here, but this patch fixes the regression.

rdar://47644670

Thanks!
Erik


Repository:
  rC Clang

https://reviews.llvm.org/D58145

Files:
  clang/lib/Sema/SemaChecking.cpp
  clang/test/SemaObjC/conversion.m


Index: clang/test/SemaObjC/conversion.m
===================================================================
--- clang/test/SemaObjC/conversion.m
+++ clang/test/SemaObjC/conversion.m
@@ -14,4 +14,11 @@
   x = y; // expected-warning {{implicit conversion loses integer precision: 'int' to 'char'}}
 }
 
+__attribute__((objc_root_class)) @interface DoubleProp
+ at property double d;
+ at end
 
+void use_double_prop(DoubleProp *dp) {
+  double local = 42;
+  dp.d += local;
+}
Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -10624,16 +10624,15 @@
   // The below checks assume source is floating point.
   if (!ResultBT || !RBT || !RBT->isFloatingPoint()) return;
 
-  // If source is floating point but target is not.
-  if (!ResultBT->isFloatingPoint())
-    return DiagnoseFloatingImpCast(S, E, E->getRHS()->getType(),
-                                   E->getExprLoc());
-
-  // If both source and target are floating points.
-  // Builtin FP kinds are ordered by increasing FP rank.
-  if (ResultBT->getKind() < RBT->getKind() &&
-      // We don't want to warn for system macro.
-      !S.SourceMgr.isInSystemMacro(E->getOperatorLoc()))
+  // If source is floating point but target is an integer.
+  if (ResultBT->isInteger())
+    DiagnoseFloatingImpCast(S, E, E->getRHS()->getType(), E->getExprLoc());
+  // If both source and target are floating points. Builtin FP kinds are ordered
+  // by increasing FP rank. FIXME: except _Float16, we currently emit a bogus
+  // warning.
+  else if (ResultBT->isFloatingType() && ResultBT->getKind() < RBT->getKind() &&
+           // We don't want to warn for system macro.
+           !S.SourceMgr.isInSystemMacro(E->getOperatorLoc()))
     // warn about dropping FP rank.
     DiagnoseImpCast(S, E->getRHS(), E->getLHS()->getType(), E->getOperatorLoc(),
                     diag::warn_impcast_float_result_precision);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D58145.186533.patch
Type: text/x-patch
Size: 1998 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20190212/c7344453/attachment.bin>