[Modules] Fix creating fake definition data for lambdas.
During reading C++ definition data for lambda we can access
CXXRecordDecl representing lambda before we finished reading the
definition data. This can happen by reading a captured variable which is
VarDecl, then reading its decl context which is CXXMethodDecl `operator()`,
then trying to merge redeclarable methods and accessing
enclosing CXXRecordDecl. The call stack looks roughly like
VisitCXXRecordDecl
ReadCXXRecordDefinition
VisitVarDecl
VisitCXXMethodDecl
mergeRedeclarable
getPrimaryContextForMerging
If we add fake definition data at this point, later we'll hit the assertion
Assertion failed: (!DD.IsLambda && !MergeDD.IsLambda && "faked up lambda definition?"), function MergeDefinitionData, file clang/lib/Serialization/ASTReaderDecl.cpp, line 1675.
The fix is to assign definition data before reading it. Fixes PR32556.
rdar://problem/37461072
Reviewers: rsmith, bruno
Reviewed By: rsmith
Subscribers: cfe-commits, jkorous-apple, aprantl
Differential Revision: https://reviews.llvm.org/D43494
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@328153 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 733748c..360265b 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1784,29 +1784,31 @@
else
DD = new (C) struct CXXRecordDecl::DefinitionData(D);
+ CXXRecordDecl *Canon = D->getCanonicalDecl();
+ // Set decl definition data before reading it, so that during deserialization
+ // when we read CXXRecordDecl, it already has definition data and we don't
+ // set fake one.
+ if (!Canon->DefinitionData)
+ Canon->DefinitionData = DD;
+ D->DefinitionData = Canon->DefinitionData;
ReadCXXDefinitionData(*DD, D);
- // We might already have a definition for this record. This can happen either
- // because we're reading an update record, or because we've already done some
- // merging. Either way, just merge into it.
- CXXRecordDecl *Canon = D->getCanonicalDecl();
- if (Canon->DefinitionData) {
+ // We might already have a different definition for this record. This can
+ // happen either because we're reading an update record, or because we've
+ // already done some merging. Either way, just merge into it.
+ if (Canon->DefinitionData != DD) {
MergeDefinitionData(Canon, std::move(*DD));
- D->DefinitionData = Canon->DefinitionData;
return;
}
// Mark this declaration as being a definition.
D->IsCompleteDefinition = true;
- D->DefinitionData = DD;
// If this is not the first declaration or is an update record, we can have
// other redeclarations already. Make a note that we need to propagate the
// DefinitionData pointer onto them.
- if (Update || Canon != D) {
- Canon->DefinitionData = D->DefinitionData;
+ if (Update || Canon != D)
Reader.PendingDefinitions.insert(D);
- }
}
ASTDeclReader::RedeclarableResult
diff --git a/test/Modules/Inputs/self-referencing-lambda/a.h b/test/Modules/Inputs/self-referencing-lambda/a.h
new file mode 100644
index 0000000..756fe18
--- /dev/null
+++ b/test/Modules/Inputs/self-referencing-lambda/a.h
@@ -0,0 +1,4 @@
+void f() {
+ int x = 0;
+ auto q = [xm = x]{};
+}
diff --git a/test/Modules/Inputs/self-referencing-lambda/module.modulemap b/test/Modules/Inputs/self-referencing-lambda/module.modulemap
new file mode 100644
index 0000000..812ca9d
--- /dev/null
+++ b/test/Modules/Inputs/self-referencing-lambda/module.modulemap
@@ -0,0 +1,4 @@
+module "a.h" {
+ header "a.h"
+ export *
+}
diff --git a/test/Modules/self-referencing-lambda.cpp b/test/Modules/self-referencing-lambda.cpp
new file mode 100644
index 0000000..ea9553f
--- /dev/null
+++ b/test/Modules/self-referencing-lambda.cpp
@@ -0,0 +1,5 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I %S/Inputs/self-referencing-lambda %s -verify -emit-obj -o %t2.o
+// expected-no-diagnostics
+
+#include "a.h"
