From 0bcdfea9041f7d7a2c7ed642e53b2a5bc43a37a5 Mon Sep 17 00:00:00 2001
From: Ben Langmuir <blangmuir@apple.com>
Date: Fri, 11 Dec 2015 22:05:13 +0000
Subject: [PATCH] Reapply "[Modules] Fix regression when an
elaborated-type-specifier mentions a hidden tag"
Now not trying to use a C++ lookup mechanism in C (d'oh). Unqualified
lookup is actually fine for this case in C.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@255377 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/Sema/SemaDecl.cpp | 7 +++++++
test/Modules/Inputs/elaborated-type-structs.h | 3 +++
test/Modules/Inputs/module.map | 7 +++++++
...borated-type-specifier-from-hidden-module.m | 18 ++++++++++++++++++
4 files changed, 35 insertions(+)
create mode 100644 test/Modules/Inputs/elaborated-type-structs.h
create mode 100644 test/Modules/elaborated-type-specifier-from-hidden-module.m
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 6a61ac0e44c..f9c1a014260 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -12136,9 +12136,16 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
// In C++, we need to do a redeclaration lookup to properly
// diagnose some problems.
+ // FIXME: redeclaration lookup is also used (with and without C++) to find a
+ // hidden declaration so that we don't get ambiguity errors when using a
+ // type declared by an elaborated-type-specifier. In C that is not correct
+ // and we should instead merge compatible types found by lookup.
if (getLangOpts().CPlusPlus) {
Previous.setRedeclarationKind(ForRedeclaration);
LookupQualifiedName(Previous, SearchDC);
+ } else {
+ Previous.setRedeclarationKind(ForRedeclaration);
+ LookupName(Previous, S);
}
}
diff --git a/test/Modules/Inputs/elaborated-type-structs.h b/test/Modules/Inputs/elaborated-type-structs.h
new file mode 100644
index 00000000000..da3940998fd
--- /dev/null
+++ b/test/Modules/Inputs/elaborated-type-structs.h
@@ -0,0 +1,3 @@
+struct S1;
+struct S2 { int x; };
+struct S3 { int x; };
diff --git a/test/Modules/Inputs/module.map b/test/Modules/Inputs/module.map
index 226d45fdf44..632517dd363 100644
--- a/test/Modules/Inputs/module.map
+++ b/test/Modules/Inputs/module.map
@@ -386,3 +386,10 @@ module TypedefTag {
header "typedef-tag-hidden.h"
}
}
+
+module ElaboratedTypeStructs {
+ module Empty {}
+ module Structs {
+ header "elaborated-type-structs.h"
+ }
+}
diff --git a/test/Modules/elaborated-type-specifier-from-hidden-module.m b/test/Modules/elaborated-type-specifier-from-hidden-module.m
new file mode 100644
index 00000000000..0ca1c24bba0
--- /dev/null
+++ b/test/Modules/elaborated-type-specifier-from-hidden-module.m
@@ -0,0 +1,18 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I %S/Inputs %s -verify
+
+@import ElaboratedTypeStructs.Empty; // The structs are now hidden.
+struct S1 *x;
+struct S2 *y;
+// FIXME: compatible definition should not be an error.
+struct S2 { int x; }; // expected-error {{redefinition}}
+struct S3 *z;
+// Incompatible definition.
+struct S3 { float y; }; // expected-error {{redefinition}}
+// expected-note@elaborated-type-structs.h:* 2 {{previous definition is here}}
+
+@import ElaboratedTypeStructs.Structs;
+
+void useS1(struct S1 *x);
+void useS2(struct S2 *x);
+void useS2(struct S2 *x);
--
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