commit 5c845c1c50ac89a6f12557d1571678f3d1432478
author Richard Smith <richard@metafoo.co.uk> Mon Mar 09 17:34:33 2020 -0700
committer Richard Smith <richard@metafoo.co.uk> Tue Mar 10 14:45:04 2020 -0700
tree 002b06e33659b67aeba53a6f0c4a621a15e920cb
parent 200b20639ac2804318dee9fddfe79c7fea7bd623

PR45083: Mark statement expressions as being dependent if they appear in
a dependent context.

This matches the GCC behavior.

We track the enclosing template depth when determining whether a
statement expression is within a dependent context; there doesn't appear
to be any other reliable way to determine this.

We previously assumed they were neither value- nor
instantiation-dependent under any circumstances, which would lead to
crashes and other misbehavior.

clang/lib/Serialization/ASTReaderStmt.cpp

diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 4c1abde..1a3e299 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -1205,6 +1205,7 @@
   E->setLParenLoc(readSourceLocation());
   E->setRParenLoc(readSourceLocation());
   E->setSubStmt(cast_or_null<CompoundStmt>(Record.readSubStmt()));
+  E->StmtExprBits.TemplateDepth = Record.readInt();
 }
 
 void ASTStmtReader::VisitChooseExpr(ChooseExpr *E) {

clang/lib/Serialization/ASTWriterStmt.cpp

diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index bf63ac3..cea0fc0 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -1069,6 +1069,7 @@
   Record.AddStmt(E->getSubStmt());
   Record.AddSourceLocation(E->getLParenLoc());
   Record.AddSourceLocation(E->getRParenLoc());
+  Record.push_back(E->getTemplateDepth());
   Code = serialization::EXPR_STMT;
 }