[clang] aca191c - Re-land 7a527f17776be78ec44b88e82b39afb65fc148e4 with fixes.

[Aaron Ballman via cfe-commits]

Author: Vaibhav Garg
Date: 2020-08-21T14:40:09-04:00
New Revision: aca191cce1c4dbab28a65cfe4caa6348e698a2b3

URL: https://github.com/llvm/llvm-project/commit/aca191cce1c4dbab28a65cfe4caa6348e698a2b3
DIFF: https://github.com/llvm/llvm-project/commit/aca191cce1c4dbab28a65cfe4caa6348e698a2b3.diff

LOG: Re-land 7a527f17776be78ec44b88e82b39afb65fc148e4 with fixes.

The original commit was reverted in 58c305f466d1f78adb10e7295b9bc9fc192a6e09
due to broken bots. This commit corrects the triple and command line paths.

Added: 
    clang/test/Modules/Inputs/inherit-attribute/a.h
    clang/test/Modules/Inputs/inherit-attribute/b.h
    clang/test/Modules/Inputs/inherit-attribute/c.h
    clang/test/Modules/Inputs/inherit-attribute/module.modulemap
    clang/test/Modules/inherit-attribute.cpp

Modified: 
    clang/lib/Serialization/ASTReaderDecl.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index d76182847e9d..c7a009d1e50d 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -281,6 +281,9 @@ namespace clang {
     static Decl *getMostRecentDeclImpl(...);
     static Decl *getMostRecentDecl(Decl *D);
 
+    static void mergeInheritableAttributes(ASTReader &Reader, Decl *D,
+                                           Decl *Previous);
+
     template <typename DeclT>
     static void attachPreviousDeclImpl(ASTReader &Reader,
                                        Redeclarable<DeclT> *D, Decl *Previous,
@@ -3511,6 +3514,19 @@ Decl *ASTReader::getMostRecentExistingDecl(Decl *D) {
   return ASTDeclReader::getMostRecentDecl(D->getCanonicalDecl());
 }
 
+void ASTDeclReader::mergeInheritableAttributes(ASTReader &Reader, Decl *D,
+                                               Decl *Previous) {
+  InheritableAttr *NewAttr = nullptr;
+  ASTContext &Context = Reader.getContext();
+  const auto *IA = Previous->getAttr<MSInheritanceAttr>();
+
+  if (IA && !D->hasAttr<MSInheritanceAttr>()) {
+    NewAttr = cast<InheritableAttr>(IA->clone(Context));
+    NewAttr->setInherited(true);
+    D->addAttr(NewAttr);
+  }
+}
+
 template<typename DeclT>
 void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
                                            Redeclarable<DeclT> *D,
@@ -3669,6 +3685,12 @@ void ASTDeclReader::attachPreviousDecl(ASTReader &Reader, Decl *D,
   if (auto *TD = dyn_cast<TemplateDecl>(D))
     inheritDefaultTemplateArguments(Reader.getContext(),
                                     cast<TemplateDecl>(Previous), TD);
+
+  // If any of the declaration in the chain contains an Inheritable attribute,
+  // it needs to be added to all the declarations in the redeclarable chain.
+  // FIXME: Only the logic of merging MSInheritableAttr is present, it should
+  // be extended for all inheritable attributes.
+  mergeInheritableAttributes(Reader, D, Previous);
 }
 
 template<typename DeclT>

diff  --git a/clang/test/Modules/Inputs/inherit-attribute/a.h b/clang/test/Modules/Inputs/inherit-attribute/a.h
new file mode 100644
index 000000000000..04aabe9e8c61
--- /dev/null
+++ b/clang/test/Modules/Inputs/inherit-attribute/a.h
@@ -0,0 +1,10 @@
+#ifndef FOO
+#define FOO
+
+class Foo {
+public:
+  void step(int v);
+  Foo();
+};
+
+#endif

diff  --git a/clang/test/Modules/Inputs/inherit-attribute/b.h b/clang/test/Modules/Inputs/inherit-attribute/b.h
new file mode 100644
index 000000000000..9cd1f55b9d33
--- /dev/null
+++ b/clang/test/Modules/Inputs/inherit-attribute/b.h
@@ -0,0 +1,5 @@
+#include "a.h"
+
+void bar() {
+  &Foo::step;
+}

diff  --git a/clang/test/Modules/Inputs/inherit-attribute/c.h b/clang/test/Modules/Inputs/inherit-attribute/c.h
new file mode 100644
index 000000000000..2243de1baf9a
--- /dev/null
+++ b/clang/test/Modules/Inputs/inherit-attribute/c.h
@@ -0,0 +1 @@
+#include "a.h"

diff  --git a/clang/test/Modules/Inputs/inherit-attribute/module.modulemap b/clang/test/Modules/Inputs/inherit-attribute/module.modulemap
new file mode 100644
index 000000000000..16481e2745dd
--- /dev/null
+++ b/clang/test/Modules/Inputs/inherit-attribute/module.modulemap
@@ -0,0 +1,3 @@
+module "b" { header "b.h" }
+
+module "c" { header "c.h" }

diff  --git a/clang/test/Modules/inherit-attribute.cpp b/clang/test/Modules/inherit-attribute.cpp
new file mode 100644
index 000000000000..980b30ef4975
--- /dev/null
+++ b/clang/test/Modules/inherit-attribute.cpp
@@ -0,0 +1,20 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -triple x86_64-pc-windows-msvc -I%S/Inputs/inherit-attribute -fmodules-cache-path=%t \
+// RUN: -fimplicit-module-maps -fmodules-local-submodule-visibility %s -ast-dump-all \
+// RUN: | FileCheck %s
+
+#include "b.h"
+#include "c.h"
+
+class Foo;
+
+Foo f;
+
+// CHECK:   CXXRecordDecl {{.*}} imported in b {{.*}} Foo
+// CHECK:   MSInheritanceAttr {{[^()]*$}}
+
+// CHECK:   CXXRecordDecl {{.*}} prev {{.*}} imported in c {{.*}} Foo
+// CHECK:   MSInheritanceAttr {{.*}} Inherited {{[^()]*$}}
+
+// CHECK:   CXXRecordDecl {{.*}} <line:9:1, col:7> col:7 referenced class Foo
+// CHECK:   MSInheritanceAttr {{.*}} Inherited {{[^()]*$}}