Merging r296656:
------------------------------------------------------------------------
r296656 | bruno | 2017-03-01 11:18:42 -0800 (Wed, 01 Mar 2017) | 34 lines
[PCH] Avoid VarDecl emission attempt if no owning module avaiable
This is a stopgap fix for PR31863, a regression introduced in r276159.
Consider this snippet:
struct FVector;
struct FVector {};
struct FBox {
FVector Min;
FBox(int);
};
namespace {
FBox InvalidBoundingBox(0);
}
While parsing the DECL_VAR for 'struct FBox', clang recursively read all the
dep decls until it finds the DECL_CXX_RECORD forward declaration for 'struct
FVector'. Then, it resumes all the way up back to DECL_VAR handling in
`ReadDeclRecord`, where it checks if `isConsumerInterestedIn` for the decl.
One of the condition for `isConsumerInterestedIn` to return false is if the
VarDecl is imported from a module `D->getImportedOwningModule()`, because it
will get emitted when we import the relevant module. However, before checking
if it comes from a module, clang checks if `Ctx.DeclMustBeEmitted(D)`, which
triggers the emission of 'struct FBox'. Since one of its fields is still
incomplete, it crashes.
Instead, check if `D->getImportedOwningModule()` is true before calling
`Ctx.DeclMustBeEmitted(D)`.
Differential Revision: https://reviews.llvm.org/D29753
rdar://problem/30173654
------------------------------------------------------------------------
llvm-svn: 296762
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index c691919..707a924 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -2513,8 +2513,8 @@
// An ImportDecl or VarDecl imported from a module will get emitted when
// we import the relevant module.
- if ((isa<ImportDecl>(D) || isa<VarDecl>(D)) && Ctx.DeclMustBeEmitted(D) &&
- D->getImportedOwningModule())
+ if ((isa<ImportDecl>(D) || isa<VarDecl>(D)) && D->getImportedOwningModule() &&
+ Ctx.DeclMustBeEmitted(D))
return false;
if (isa<FileScopeAsmDecl>(D) ||
diff --git a/clang/test/PCH/empty-def-fwd-struct.h b/clang/test/PCH/empty-def-fwd-struct.h
new file mode 100644
index 0000000..dda9827
--- /dev/null
+++ b/clang/test/PCH/empty-def-fwd-struct.h
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -emit-pch -x c++-header %s -std=c++14 -o %t.pch
+// RUN: %clang_cc1 -emit-llvm-only -x c++ /dev/null -std=c++14 -include-pch %t.pch -o %t.o
+struct FVector;
+struct FVector {};
+struct FBox {
+ FVector Min;
+ FBox(int);
+};
+namespace {
+FBox InvalidBoundingBox(0);
+}
+
