From: Tim Northover <tnorthover@apple.com>
Date: Fri, 7 Jun 2013 00:04:50 +0000 (+0000)
Subject: Diagnose malformed x86 inline asm using 'y' constraint.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1bea653e0d0f0182ed6e0deb5c18ad1123bb3bbd;p=clang

Diagnose malformed x86 inline asm using 'y' constraint.

X86's 'y' inline assembly constraint represents an MMX register, this change
prevents Clang from hitting an assertion when passed an incompatible type to
deal with.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183467 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 353d6c3d39..3e9b8d47ea 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -16,6 +16,7 @@
 #include "CodeGenModule.h"
 #include "TargetInfo.h"
 #include "clang/AST/StmtVisitor.h"
+#include "clang/Sema/SemaDiagnostic.h"
 #include "clang/Basic/PrettyStackTrace.h"
 #include "clang/Basic/TargetInfo.h"
 #include "llvm/ADT/StringExtras.h"
@@ -1559,10 +1560,15 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
           ResultRegTypes.back() = ConvertType(InputTy);
         }
       }
-      if (llvm::Type* AdjTy = 
+      if (llvm::Type* AdjTy =
             getTargetHooks().adjustInlineAsmType(*this, OutputConstraint,
                                                  ResultRegTypes.back()))
         ResultRegTypes.back() = AdjTy;
+      else {
+        CGM.getDiags().Report(S.getAsmLoc(),
+                              diag::err_asm_invalid_type_in_input)
+            << OutExpr->getType() << OutputConstraint;
+      }
     } else {
       ArgTypes.push_back(Dest.getAddress()->getType());
       Args.push_back(Dest.getAddress());
@@ -1578,8 +1584,8 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
                                             InOutConstraints);
 
       if (llvm::Type* AdjTy =
-            getTargetHooks().adjustInlineAsmType(*this, OutputConstraint,
-                                                 Arg->getType()))
+          getTargetHooks().adjustInlineAsmType(*this, OutputConstraint,
+                                               Arg->getType()))
         Arg = Builder.CreateBitCast(Arg, AdjTy);
 
       if (Info.allowsRegister())
@@ -1644,6 +1650,9 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
               getTargetHooks().adjustInlineAsmType(*this, InputConstraint,
                                                    Arg->getType()))
       Arg = Builder.CreateBitCast(Arg, AdjTy);
+    else
+      CGM.getDiags().Report(S.getAsmLoc(), diag::err_asm_invalid_type_in_input)
+          << InputExpr->getType() << InputConstraint;
 
     ArgTypes.push_back(Arg->getType());
     Args.push_back(Arg);
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index c4ee7246a5..6881ea7fec 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -503,8 +503,16 @@ bool IsX86_MMXType(llvm::Type *IRType) {
 static llvm::Type* X86AdjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
                                           StringRef Constraint,
                                           llvm::Type* Ty) {
-  if ((Constraint == "y" || Constraint == "&y") && Ty->isVectorTy())
+  if ((Constraint == "y" || Constraint == "&y") && Ty->isVectorTy()) {
+    if (cast<llvm::VectorType>(Ty)->getBitWidth() != 64) {
+      // Invalid MMX constraint
+      return 0;
+    }
+
     return llvm::Type::getX86_MMXTy(CGF.getLLVMContext());
+  }
+
+  // No operation needed
   return Ty;
 }
 
diff --git a/lib/CodeGen/TargetInfo.h b/lib/CodeGen/TargetInfo.h
index b0ddebc1a0..ab7b061aba 100644
--- a/lib/CodeGen/TargetInfo.h
+++ b/lib/CodeGen/TargetInfo.h
@@ -111,8 +111,13 @@ namespace clang {
       return Address;
     }
 
+    /// Corrects the low-level LLVM type for a given constraint and "usual"
+    /// type.
+    ///
+    /// \returns A pointer to a new LLVM type, possibly the same as the original
+    /// on success; 0 on failure.
     virtual llvm::Type* adjustInlineAsmType(CodeGen::CodeGenFunction &CGF,
-                                            StringRef Constraint, 
+                                            StringRef Constraint,
                                             llvm::Type* Ty) const {
       return Ty;
     }
diff --git a/test/CodeGen/mmx-inline-asm-error.c b/test/CodeGen/mmx-inline-asm-error.c
new file mode 100644
index 0000000000..a6393682ce
--- /dev/null
+++ b/test/CodeGen/mmx-inline-asm-error.c
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -verify -triple x86_64-unknown-unknown -emit-llvm-only %s
+typedef int vec256 __attribute__((ext_vector_type(8)));
+
+vec256 foo(vec256 in) {
+  vec256 out;
+
+  asm("something %0" : : "y"(in)); // expected-error {{invalid type 'vec256' in asm input for constraint 'y'}}
+  asm("something %0" : "=y"(out)); // expected-error {{invalid type 'vec256' in asm input for constraint 'y'}}
+  asm("something %0, %0" : "+y"(out)); // expected-error {{invalid type 'vec256' in asm input for constraint 'y'}}
+
+  return out;
+}
+