Explictly track tentative definitions within Sema, then hand those

tentative definitions off to the ASTConsumer at the end of the
translation unit. 

Eliminate CodeGen's internal tracking of tentative definitions, and
instead hook into ASTConsumer::CompleteTentativeDefinition. Also,
tweak the definition-deferal logic for C++, where there are no
tentative definitions.

Fixes <rdar://problem/6808352>, and will make it much easier for
precompiled headers to cope with tentative definitions in the future.

llvm-svn: 69681

3 files changed, 8 insertions, 4 deletions

diff --git a/clang/test/PCH/external-defs.h b/clang/test/PCH/external-defs.h
index 4d233e2a404..bb51a9d64b9 100644
--- a/clang/test/PCH/external-defs.h
+++ b/clang/test/PCH/external-defs.h
@@ -14,5 +14,4 @@ static int z;
 int incomplete_array[];
 int incomplete_array2[];
 
-// FIXME: CodeGen problems prevents this from working (<rdar://problem/6762287>)
-// struct S s;
+struct S s;
diff --git a/clang/test/Sema/init.c b/clang/test/Sema/init.c
index cbf75e1bb1c..7938ec5568d 100644
--- a/clang/test/Sema/init.c
+++ b/clang/test/Sema/init.c
@@ -74,8 +74,7 @@ int sym_fw1a_scr[] = {
 };
 
 // PR3001
-struct s1 s2 = { // expected-error{{tentative definition has type 'struct s1' that is never completed}} \
-  // expected-note{{forward declaration of 'struct s1'}}
+struct s1 s2 = {
     .a = sizeof(struct s3), // expected-error {{invalid application of 'sizeof'}} \
                             // expected-note{{forward declaration of 'struct s3'}}
     .b = bogus // expected-error {{use of undeclared identifier 'bogus'}}
diff --git a/clang/test/Sema/tentative-decls.c b/clang/test/Sema/tentative-decls.c
index 3a830bf4283..85b5ed76bd6 100644
--- a/clang/test/Sema/tentative-decls.c
+++ b/clang/test/Sema/tentative-decls.c
@@ -57,3 +57,9 @@ void func2(void)
   extern double *p;
 }
 
+// <rdar://problem/6808352>
+static int a0[];
+static int b0;
+
+static int a0[] = { 4 };
+static int b0 = 5;