[clang] 5f1f4a5 - Prohibit capture of _ExtInt in inline assembly.

[Erich Keane via cfe-commits]

Author: Erich Keane
Date: 2020-05-14T07:21:09-07:00
New Revision: 5f1f4a5d0157c11e0a88d9a273f49c8f866b01ef

URL: https://github.com/llvm/llvm-project/commit/5f1f4a5d0157c11e0a88d9a273f49c8f866b01ef
DIFF: https://github.com/llvm/llvm-project/commit/5f1f4a5d0157c11e0a88d9a273f49c8f866b01ef.diff

LOG: Prohibit capture of _ExtInt in inline assembly.

The backends don't seem to properly handle the _ExtInt type in inline
assembly with crashes occurring in many. While the ones I tested seem to
work for powers of 2 < 64 (and some any multiple of 64 greater than
that), it seemed like a better idea to just use of this type in inline
assembly prohibited.

Added: 
    

Modified: 
    clang/include/clang/Basic/DiagnosticCommonKinds.td
    clang/lib/Sema/SemaStmtAsm.cpp
    clang/test/SemaCXX/ext-int.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/DiagnosticCommonKinds.td b/clang/include/clang/Basic/DiagnosticCommonKinds.td
index 5d8c939283b5..73f55784234e 100644
--- a/clang/include/clang/Basic/DiagnosticCommonKinds.td
+++ b/clang/include/clang/Basic/DiagnosticCommonKinds.td
@@ -240,6 +240,9 @@ let CategoryName = "Inline Assembly Issue" in {
   def err_asm_invalid_type_in_input : Error<
     "invalid type %0 in asm input for constraint '%1'">;
 
+  def err_asm_invalid_type : Error<
+    "invalid type %0 in asm %select{input|output}1">;
+
   def warn_stack_clash_protection_inline_asm : Warning<
     "Unable to protect inline asm that clobbers stack pointer against stack clash">,
     InGroup<DiagGroup<"stack-protector">>;

diff  --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp
index 82a308f35c21..10fa24682f9c 100644
--- a/clang/lib/Sema/SemaStmtAsm.cpp
+++ b/clang/lib/Sema/SemaStmtAsm.cpp
@@ -296,6 +296,14 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
         checkExprMemoryConstraintCompat(*this, OutputExpr, Info, false))
       return StmtError();
 
+    // Disallow _ExtInt, since the backends tend to have 
diff iculties with
+    // non-normal sizes.
+    if (OutputExpr->getType()->isExtIntType())
+      return StmtError(
+          Diag(OutputExpr->getBeginLoc(), diag::err_asm_invalid_type)
+          << OutputExpr->getType() << 0 /*Input*/
+          << OutputExpr->getSourceRange());
+
     OutputConstraintInfos.push_back(Info);
 
     // If this is dependent, just continue.
@@ -420,6 +428,12 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       }
     }
 
+    if (InputExpr->getType()->isExtIntType())
+      return StmtError(
+          Diag(InputExpr->getBeginLoc(), diag::err_asm_invalid_type)
+          << InputExpr->getType() << 1 /*Output*/
+          << InputExpr->getSourceRange());
+
     InputConstraintInfos.push_back(Info);
 
     const Type *Ty = Exprs[i]->getType().getTypePtr();
@@ -892,6 +906,15 @@ StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
                                 SourceLocation EndLoc) {
   bool IsSimple = (NumOutputs != 0 || NumInputs != 0);
   setFunctionHasBranchProtectedScope();
+
+  for (uint64_t I = 0; I < NumOutputs + NumInputs; ++I) {
+    if (Exprs[I]->getType()->isExtIntType())
+      return StmtError(
+          Diag(Exprs[I]->getBeginLoc(), diag::err_asm_invalid_type)
+          << Exprs[I]->getType() << (I < NumOutputs)
+          << Exprs[I]->getSourceRange());
+  }
+
   MSAsmStmt *NS =
     new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple,
                             /*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs,

diff  --git a/clang/test/SemaCXX/ext-int.cpp b/clang/test/SemaCXX/ext-int.cpp
index cf94fd17162a..a5e87eb878d3 100644
--- a/clang/test/SemaCXX/ext-int.cpp
+++ b/clang/test/SemaCXX/ext-int.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s -Wimplicit-int-conversion -triple x86_64-gnu-linux
+// RUN: %clang_cc1 -fsyntax-only -verify %s -Wimplicit-int-conversion -triple x86_64-gnu-linux -fasm-blocks
 
 template<int Bounds>
 struct HasExtInt {
@@ -276,3 +276,12 @@ void ImplicitCasts(_ExtInt(31) s31, _ExtInt(33) s33, int i) {
   i = s33;
 }
 
+
+void NotAllowedInInlineAsm(_ExtInt(9) in, _ExtInt(9) out) {
+  __asm { mov eax, in} // expected-error{{invalid type '_ExtInt(9)' in asm input}}
+  __asm { mov out, eax} // expected-error{{invalid type '_ExtInt(9)' in asm output}}
+
+  asm("" : "=g" (in));// expected-error{{invalid type '_ExtInt(9)' in asm input}}
+  asm("" :: "r" (out));// expected-error{{invalid type '_ExtInt(9)' in asm output}}
+
+}