Fix for PR14269: Clang crashes when a bit field is used as inline assembler

input / output with memory constraint.
One generally can't get address of a bit field, so the general solution is to
error on such cases. GCC does the same.

Patch by Andrey Bokhanko

Differential Revision: http://reviews.llvm.org/D10086

llvm-svn: 239153

1 files changed, 16 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp
index 9f48616ea5b..d19d8819d8e 100644
--- a/clang/lib/Sema/SemaStmtAsm.cpp
+++ b/clang/lib/Sema/SemaStmtAsm.cpp
@@ -154,6 +154,14 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
     if (CheckNakedParmReference(OutputExpr, *this))
       return StmtError();
 
+    // Bitfield can't be referenced with a pointer.
+    if (Info.allowsMemory() && OutputExpr->refersToBitField())
+      return StmtError(Diag(OutputExpr->getLocStart(),
+                            diag::err_asm_bitfield_in_memory_constraint)
+                       << 1
+                       << Info.getConstraintStr()
+                       << OutputExpr->getSourceRange());
+
     OutputConstraintInfos.push_back(Info);
 
     // If this is dependent, just continue.
@@ -230,6 +238,14 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
     if (CheckNakedParmReference(InputExpr, *this))
       return StmtError();
 
+    // Bitfield can't be referenced with a pointer.
+    if (Info.allowsMemory() && InputExpr->refersToBitField())
+      return StmtError(Diag(InputExpr->getLocStart(),
+                            diag::err_asm_bitfield_in_memory_constraint)
+                       << 0
+                       << Info.getConstraintStr()
+                       << InputExpr->getSourceRange());
+
     // Only allow void types for memory constraints.
     if (Info.allowsMemory() && !Info.allowsRegister()) {
       if (CheckAsmLValue(InputExpr, *this))