[clang] ded2490 - Workaround for EvalInfo ctor for MSVC 2017

[Yaxun Liu via cfe-commits]

Author: Yaxun (Sam) Liu
Date: 2019-11-26T21:43:29-05:00
New Revision: ded249049429a26d3748926c04bd7169f0170714

URL: https://github.com/llvm/llvm-project/commit/ded249049429a26d3748926c04bd7169f0170714
DIFF: https://github.com/llvm/llvm-project/commit/ded249049429a26d3748926c04bd7169f0170714.diff

LOG: Workaround for EvalInfo ctor for MSVC 2017

Current EvalInfo ctor causes EnableNewConstInterp to be true even though
it is supposed to be false on MSVC 2017. This is because a virtual function
getLangOpts() is called in member initializer lists, whereas on MSVC
member ctors are called before function virtual function pointers are
initialized.

This patch fixes that.

Differential Revision: https://reviews.llvm.org/D70729

Added: 
    clang/test/Sema/eval-info.c

Modified: 
    clang/lib/AST/ExprConstant.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 79659261388b..eec9bbdaef80 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -921,10 +921,10 @@ namespace {
     EvalInfo(const ASTContext &C, Expr::EvalStatus &S, EvaluationMode Mode)
         : Ctx(const_cast<ASTContext &>(C)), EvalStatus(S), CurrentCall(nullptr),
           CallStackDepth(0), NextCallIndex(1),
-          StepsLeft(getLangOpts().ConstexprStepLimit),
-          ForceNewConstInterp(getLangOpts().ForceNewConstInterp),
+          StepsLeft(C.getLangOpts().ConstexprStepLimit),
+          ForceNewConstInterp(C.getLangOpts().ForceNewConstInterp),
           EnableNewConstInterp(ForceNewConstInterp ||
-                               getLangOpts().EnableNewConstInterp),
+                               C.getLangOpts().EnableNewConstInterp),
           BottomFrame(*this, SourceLocation(), nullptr, nullptr, nullptr),
           EvaluatingDecl((const ValueDecl *)nullptr),
           EvaluatingDeclValue(nullptr), HasActiveDiagnostic(false),

diff  --git a/clang/test/Sema/eval-info.c b/clang/test/Sema/eval-info.c
new file mode 100644
index 000000000000..7f4de4b90820
--- /dev/null
+++ b/clang/test/Sema/eval-info.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -fsyntax-only -triple x86_64-unknown-windows-msvc -verify
+
+// expected-no-diagnostics
+
+// Make sure the new constant interpolator is not enabled unintentionally
+// to cause assertion.
+typedef enum x {
+  a = 1,
+} x;