Track the result of evaluating a computed noexcept specification on the

FunctionProtoType.

We previously re-evaluated the expression each time we wanted to know whether
the type is noexcept or not. We now evaluate the expression exactly once.

This is not quite "no functional change": it fixes a crasher bug during AST
deserialization where we would try to evaluate the noexcept specification in a
situation where we have not deserialized sufficient portions of the AST to
permit such evaluation.

llvm-svn: 331428

1 files changed, 5 insertions, 9 deletions

diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 2be3e2578d4..b37ecaa7351 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -442,11 +442,9 @@ void CodeGenFunction::EmitStartEHSpec(const Decl *D) {
     return;
 
   ExceptionSpecificationType EST = Proto->getExceptionSpecType();
-  if (isNoexceptExceptionSpec(EST)) {
-    if (Proto->getNoexceptSpec(getContext()) == FunctionProtoType::NR_Nothrow) {
-      // noexcept functions are simple terminate scopes.
-      EHStack.pushTerminate();
-    }
+  if (isNoexceptExceptionSpec(EST) && Proto->canThrow() == CT_Cannot) {
+    // noexcept functions are simple terminate scopes.
+    EHStack.pushTerminate();
   } else if (EST == EST_Dynamic || EST == EST_DynamicNone) {
     // TODO: Revisit exception specifications for the MS ABI.  There is a way to
     // encode these in an object file but MSVC doesn't do anything with it.
@@ -521,10 +519,8 @@ void CodeGenFunction::EmitEndEHSpec(const Decl *D) {
     return;
 
   ExceptionSpecificationType EST = Proto->getExceptionSpecType();
-  if (isNoexceptExceptionSpec(EST)) {
-    if (Proto->getNoexceptSpec(getContext()) == FunctionProtoType::NR_Nothrow) {
-      EHStack.popTerminate();
-    }
+  if (isNoexceptExceptionSpec(EST) && Proto->canThrow() == CT_Cannot) {
+    EHStack.popTerminate();
   } else if (EST == EST_Dynamic || EST == EST_DynamicNone) {
     // TODO: Revisit exception specifications for the MS ABI.  There is a way to
     // encode these in an object file but MSVC doesn't do anything with it.