[Modules] Cope better with top-level declarations loaded after being declared in the current translation unit <rdar://problem/13189985>.
These two related tweaks to keep the information associated with a
given identifier correct when the identifier has been given some
top-level information (say, a top-level declaration) and more
information is then loaded from a module. The first ensures that an
identifier that was "interesting" before being loaded from an AST is
considered to be different from its on-disk counterpart. Otherwise, we
lose such changes when writing the current translation unit as a
module.
Second, teach the code that injects AST-loaded names into the
identifier chain for name lookup to keep the most recent declaration,
so that we don't end up confusing our declaration chains by having a
different declaration in there.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174895 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/IdentifierResolver.cpp b/lib/Sema/IdentifierResolver.cpp
index 6f5ddca..d44c1fb 100644
--- a/lib/Sema/IdentifierResolver.cpp
+++ b/lib/Sema/IdentifierResolver.cpp
@@ -302,6 +302,14 @@
// If the declarations are redeclarations of each other, keep the newest one.
if (Existing->getCanonicalDecl() == New->getCanonicalDecl()) {
+ // If either of these is the most recent declaration, use it.
+ Decl *MostRecent = Existing->getMostRecentDecl();
+ if (Existing == MostRecent)
+ return DMK_Ignore;
+
+ if (New == MostRecent)
+ return DMK_Replace;
+
// If the existing declaration is somewhere in the previous declaration
// chain of the new declaration, then prefer the new declaration.
for (Decl::redecl_iterator RD = New->redecls_begin(),
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index a00d406..53fa21f 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -457,6 +457,16 @@
return StringRef((const char*) d, n-1);
}
+/// \brief Whether the given identifier is "interesting".
+static bool isInterestingIdentifier(IdentifierInfo &II) {
+ return II.isPoisoned() ||
+ II.isExtensionToken() ||
+ II.getObjCOrBuiltinID() ||
+ II.hasRevertedTokenIDToIdentifier() ||
+ II.hadMacroDefinition() ||
+ II.getFETokenInfo<void>();
+}
+
IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
const unsigned char* d,
unsigned DataLen) {
@@ -477,8 +487,13 @@
KnownII = II;
}
Reader.SetIdentifierInfo(ID, II);
- II->setIsFromAST();
- Reader.markIdentifierUpToDate(II);
+ if (!II->isFromAST()) {
+ bool WasInteresting = isInterestingIdentifier(*II);
+ II->setIsFromAST();
+ if (WasInteresting)
+ II->setChangedSinceDeserialization();
+ }
+ Reader.markIdentifierUpToDate(II);
return II;
}
@@ -506,7 +521,12 @@
KnownII = II;
}
Reader.markIdentifierUpToDate(II);
- II->setIsFromAST();
+ if (!II->isFromAST()) {
+ bool WasInteresting = isInterestingIdentifier(*II);
+ II->setIsFromAST();
+ if (WasInteresting)
+ II->setChangedSinceDeserialization();
+ }
// Set or check the various bits in the IdentifierInfo structure.
// Token IDs are read-only.
diff --git a/test/Modules/Inputs/module.map b/test/Modules/Inputs/module.map
index 2e6ef08..eeb8d15 100644
--- a/test/Modules/Inputs/module.map
+++ b/test/Modules/Inputs/module.map
@@ -86,6 +86,10 @@
export *
}
module redecl_merge_bottom {
+ explicit module prefix {
+ header "redecl-merge-bottom-prefix.h"
+ }
+
header "redecl-merge-bottom.h"
export *
}
diff --git a/test/Modules/Inputs/redecl-merge-bottom-prefix.h b/test/Modules/Inputs/redecl-merge-bottom-prefix.h
new file mode 100644
index 0000000..6501e1b
--- /dev/null
+++ b/test/Modules/Inputs/redecl-merge-bottom-prefix.h
@@ -0,0 +1,4 @@
+// A class that is declared in the 'bottom' module, then loaded from
+// one of the modules it depends on. It needs to be visible when this
+// module is loaded.
+@class DeclaredThenLoaded;
diff --git a/test/Modules/Inputs/redecl-merge-bottom.h b/test/Modules/Inputs/redecl-merge-bottom.h
index 28ea20c..b8fb179 100644
--- a/test/Modules/Inputs/redecl-merge-bottom.h
+++ b/test/Modules/Inputs/redecl-merge-bottom.h
@@ -18,3 +18,8 @@
void refers_to_C4(C4*);
+@interface UnrelatedToDeclaredThenLoaded
+- declaredThenLoadedMethod;
+@end
+
+@class DeclaredThenLoaded;
diff --git a/test/Modules/Inputs/redecl-merge-left.h b/test/Modules/Inputs/redecl-merge-left.h
index 973d594..cf07165 100644
--- a/test/Modules/Inputs/redecl-merge-left.h
+++ b/test/Modules/Inputs/redecl-merge-left.h
@@ -82,3 +82,11 @@
// top level.
typedef void funcptr_with_id(int id);
+// A class that is declared in the 'bottom' module, then loaded from
+// one of the modules it depends on.
+@interface DeclaredThenLoaded
+- declaredThenLoadedMethod;
+@end
+
+@class DeclaredThenLoaded;
+
diff --git a/test/Modules/redecl-merge2.m b/test/Modules/redecl-merge2.m
new file mode 100644
index 0000000..3431ecc
--- /dev/null
+++ b/test/Modules/redecl-merge2.m
@@ -0,0 +1,8 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -I %S/Inputs %s -verify -Wno-objc-root-class
+// expected-no-diagnostics
+
+@import redecl_merge_bottom.prefix;
+
+DeclaredThenLoaded *dtl;
+
