From 887b485dbe3dec6fb0387cf80c0e79f02bc7201d Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Mon, 12 Nov 2012 06:42:51 +0000
Subject: [PATCH] Check that the input size is correct for the given
 constraint.

The 'a', 'c', and 'd' constraints on i386 mean a 32-bit register. We cannot
place a 64-bit value into the 32-bit register. Error out instead of causing the
compiler to spew general badness.
<rdar://problem/12415959>

llvm-svn: 167717
---
 clang/include/clang/Basic/DiagnosticSemaKinds.td |  2 ++
 clang/include/clang/Basic/TargetInfo.h           |  4 ++++
 clang/lib/Basic/Targets.cpp                      | 13 +++++++++++++
 clang/lib/Sema/SemaStmtAsm.cpp                   | 11 +++++++++++
 clang/test/CodeGen/x86_32-inline-asm.c           | 18 ++++++++++++++++++
 5 files changed, 48 insertions(+)
 create mode 100644 clang/test/CodeGen/x86_32-inline-asm.c

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 0d64bf3..9110fa3 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -5141,6 +5141,8 @@ let CategoryName = "Inline Assembly Issue" in {
     "%diff{$ matching output with type $|}0,1">;
   def err_asm_unknown_register_name : Error<"unknown register name '%0' in asm">;
   def err_asm_empty : Error<"__asm used with no assembly instructions">;
+  def err_asm_invalid_input_size : Error<
+    "invalid input size for constraint '%0'">;
   def err_invalid_asm_cast_lvalue : Error<
     "invalid use of a cast in a inline asm context requiring an l-value: "
     "remove the cast or build with -fheinous-gnu-extensions">;
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index b0e5805..6774e8e 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -517,6 +517,10 @@ public:
   bool validateInputConstraint(ConstraintInfo *OutputConstraints,
                                unsigned NumOutputs,
                                ConstraintInfo &info) const;
+  virtual bool validateInputSize(StringRef /*Constraint*/,
+                                 unsigned /*Size*/) const {
+    return true;
+  }
   virtual bool validateConstraintModifier(StringRef /*Constraint*/,
                                           const char /*Modifier*/,
                                           unsigned /*Size*/) const {
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 26a4f41..ea4ac27 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -2595,6 +2595,19 @@ public:
     if (RegNo == 1) return 2;
     return -1;
   }
+  virtual bool validateInputSize(StringRef Constraint,
+                                 unsigned Size) const {
+    switch (Constraint[0]) {
+    default: break;
+    case 'a':
+    case 'b':
+    case 'c':
+    case 'd':
+      return Size == 32;
+    }
+
+    return true;
+  }
 };
 } // end anonymous namespace
 
diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp
index 7c2c766..e3b5dd8 100644
--- a/clang/lib/Sema/SemaStmtAsm.cpp
+++ b/clang/lib/Sema/SemaStmtAsm.cpp
@@ -179,6 +179,17 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
 
     Exprs[i] = Result.take();
     InputConstraintInfos.push_back(Info);
+
+    const Type *Ty = Exprs[i]->getType().getTypePtr();
+    if (Ty->isDependentType() || Ty->isIncompleteType())
+      continue;
+
+    unsigned Size = Context.getTypeSize(Ty);
+    if (!Context.getTargetInfo().validateInputSize(Literal->getString(),
+                                                   Size))
+      return StmtError(Diag(InputExpr->getLocStart(),
+                            diag::err_asm_invalid_input_size)
+                       << Info.getConstraintStr());
   }
 
   // Check that the clobbers are valid.
diff --git a/clang/test/CodeGen/x86_32-inline-asm.c b/clang/test/CodeGen/x86_32-inline-asm.c
new file mode 100644
index 0000000..0596ba4
--- /dev/null
+++ b/clang/test/CodeGen/x86_32-inline-asm.c
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -verify %s
+// <rdar://problem/12415959>
+
+typedef unsigned int u_int32_t;
+typedef u_int32_t uint32_t;
+
+typedef unsigned long long u_int64_t;
+typedef u_int64_t uint64_t;
+
+int main () {
+  uint32_t msr = 0x8b;
+  uint64_t val = 0;
+  __asm__ volatile("wrmsr"
+                   :
+                   : "c" (msr),
+                     "a" ((val & 0xFFFFFFFFUL)), // expected-error {{invalid input size for constraint 'a'}}
+                     "d" (((val >> 32) & 0xFFFFFFFFUL)));
+}
-- 
2.7.4