2 files changed, 37 insertions, 3 deletions
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 511817f324c..8ff30d9a048 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -1901,8 +1901,12 @@ public:
   bool validateAsmConstraint(const char *&Name,
                                      TargetInfo::ConstraintInfo &info) const override;
 
+  bool validateOutputSize(StringRef Constraint, unsigned Size) const override;
+
   bool validateInputSize(StringRef Constraint, unsigned Size) const override;
 
+  virtual bool validateOperandSize(StringRef Constraint, unsigned Size) const;
+
   std::string convertConstraint(const char *&Constraint) const override;
   const char *getClobbers() const override {
     return "~{dirflag},~{fpsr},~{flags}";
@@ -3053,8 +3057,24 @@ X86TargetInfo::validateAsmConstraint(const char *&Name,
   }
 }
 
+bool X86TargetInfo::validateOutputSize(StringRef Constraint,
+                                       unsigned Size) const {
+  // Strip off constraint modifiers.
+  while (Constraint[0] == '=' ||
+         Constraint[0] == '+' ||
+         Constraint[0] == '&')
+    Constraint = Constraint.substr(1);
+
+  return validateOperandSize(Constraint, Size);
+}
+
 bool X86TargetInfo::validateInputSize(StringRef Constraint,
                                       unsigned Size) const {
+  return validateOperandSize(Constraint, Size);
+}
+
+bool X86TargetInfo::validateOperandSize(StringRef Constraint,
+                                        unsigned Size) const {
   switch (Constraint[0]) {
   default: break;
   case 'y':
@@ -3124,8 +3144,8 @@ public:
     if (RegNo == 1) return 2;
     return -1;
   }
-  bool validateInputSize(StringRef Constraint,
-                         unsigned Size) const override {
+  bool validateOperandSize(StringRef Constraint,
+                           unsigned Size) const override {
     switch (Constraint[0]) {
     default: break;
     case 'R':
@@ -3142,7 +3162,7 @@ public:
       return Size <= 64;
     }
 
-    return X86TargetInfo::validateInputSize(Constraint, Size);
+    return X86TargetInfo::validateOperandSize(Constraint, Size);
   }
 };
 } // end anonymous namespace
diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp
index 69cf6459d22..5aa1a2c86a9 100644
--- a/clang/lib/Sema/SemaStmtAsm.cpp
+++ b/clang/lib/Sema/SemaStmtAsm.cpp
@@ -121,6 +121,20 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       return StmtError();
 
     OutputConstraintInfos.push_back(Info);
+
+    const Type *Ty = OutputExpr->getType().getTypePtr();
+
+    // If this is a dependent type, just continue. We don't know the size of a
+    // dependent type.
+    if (Ty->isDependentType())
+      continue;
+
+    unsigned Size = Context.getTypeSize(Ty);
+    if (!Context.getTargetInfo().validateOutputSize(Literal->getString(),
+                                                    Size))
+      return StmtError(Diag(OutputExpr->getLocStart(),
+                            diag::err_asm_invalid_output_size)
+                       << Info.getConstraintStr());
   }
 
   SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;