[AST] Fix printing tag decl groups in decl contexts

For example, given:

  struct T1 {
    struct T2 *p0;
  };

-ast-print produced:

  struct T1 {
    struct T2;
    struct T2 *p0;
  };

Compiling that produces a warning that the first struct T2 declaration
does not declare anything.

Details:

A tag decl group is one or more decls that share a type specifier that
is a tag decl (that is, a struct/union/class/enum decl).  Within
functions, the parser builds such a tag decl group as part of a
DeclStmt.  However, in decl contexts, such as file scope or a member
list, the parser does not group together the members of a tag decl
group.  Previously, detection of tag decl groups during printing was
implemented but only if the tag decl was unnamed.  Otherwise, as in
the above example, the members of the group did not print together and
so sometimes introduced warnings.

This patch extends detection of tag decl groups in decl contexts to
any tag decl that is recorded in the AST as not free-standing.

Reviewed by: rsmith

Differential Revision: https://reviews.llvm.org/D45465

llvm-svn: 332314

1 files changed, 63 insertions, 26 deletions

diff --git a/clang/test/Misc/ast-print-record-decl.c b/clang/test/Misc/ast-print-record-decl.c
index e1068d8408e..c28c0aba791 100644
--- a/clang/test/Misc/ast-print-record-decl.c
+++ b/clang/test/Misc/ast-print-record-decl.c
@@ -7,8 +7,8 @@
 //   RUN: | FileCheck --check-prefixes=CHECK,LLVM %s
 //
 //   RUN: %clang_cc1 -verify -ast-print -DKW=struct -DBASES= %s > %t.c
-//   RUN: FileCheck --check-prefixes=CHECK,PRINT -DKW=struct -DBASES= %s \
-//   RUN:           --input-file %t.c
+//   RUN: FileCheck --check-prefixes=CHECK,PRINT,PRINT-C -DKW=struct -DBASES= \
+//   RUN:           %s --input-file %t.c
 //
 //   Now check compiling and printing of the printed file.
 //
@@ -19,7 +19,8 @@
 //   RUN: | FileCheck --check-prefixes=CHECK,LLVM %s
 //
 //   RUN: %clang_cc1 -verify -ast-print %t.c \
-//   RUN: | FileCheck --check-prefixes=CHECK,PRINT -DKW=struct -DBASES= %s
+//   RUN: | FileCheck --check-prefixes=CHECK,PRINT,PRINT-C -DKW=struct \
+//   RUN:             -DBASES= %s
 
 // Repeat for union:
 //
@@ -30,8 +31,8 @@
 //   RUN: | FileCheck --check-prefixes=CHECK,LLVM %s
 //
 //   RUN: %clang_cc1 -verify -ast-print -DKW=union -DBASES= %s > %t.c
-//   RUN: FileCheck --check-prefixes=CHECK,PRINT -DKW=union -DBASES= %s \
-//   RUN:           --input-file %t.c
+//   RUN: FileCheck --check-prefixes=CHECK,PRINT,PRINT-C -DKW=union -DBASES= \
+//   RUN:           %s --input-file %t.c
 //
 //   Now check compiling and printing of the printed file.
 //
@@ -42,7 +43,8 @@
 //   RUN: | FileCheck --check-prefixes=CHECK,LLVM %s
 //
 //   RUN: %clang_cc1 -verify -ast-print %t.c \
-//   RUN: | FileCheck --check-prefixes=CHECK,PRINT -DKW=union -DBASES= %s
+//   RUN: | FileCheck --check-prefixes=CHECK,PRINT,PRINT-C -DKW=union \
+//   RUN:             -DBASES= %s
 
 // Repeat for C++ (BASES helps ensure we're printing as C++ not as C):
 //
@@ -54,7 +56,7 @@
 //
 //   RUN: %clang_cc1 -verify -ast-print -DKW=struct -DBASES=' : B' -xc++ %s \
 //   RUN: > %t.cpp
-//   RUN: FileCheck --check-prefixes=CHECK,PRINT,CXX -DKW=struct \
+//   RUN: FileCheck --check-prefixes=CHECK,PRINT,PRINT-CXX -DKW=struct \
 //   RUN:           -DBASES=' : B' %s --input-file %t.cpp
 //
 //   Now check compiling and printing of the printed file.
@@ -66,7 +68,7 @@
 //   RUN: | FileCheck --check-prefixes=CHECK,LLVM %s
 //
 //   RUN: %clang_cc1 -verify -ast-print %t.cpp \
-//   RUN: | FileCheck --check-prefixes=CHECK,PRINT,CXX -DKW=struct \
+//   RUN: | FileCheck --check-prefixes=CHECK,PRINT,PRINT-CXX -DKW=struct \
 //   RUN:             -DBASES=' : B' %s
 
 // END.
@@ -155,25 +157,33 @@ void defSelfRef() {
   // expected-note@+1 2 {{'T' has been explicitly marked deprecated here}}
   KW __attribute__((deprecated(""))) T *p0;
 
-  // PRINT-NEXT: [[KW]] __attribute__((aligned(16))) T[[BASES]] {
-  // PRINT-NEXT:   int i;
-  // PRINT-NEXT:   [[KW]] T *p2;
-  // PRINT-NEXT: } *p1;
-  KW __attribute__((aligned(16))) T BASES { // expected-warning {{'T' is deprecated}}
+  // PRINT-NEXT:  [[KW]] __attribute__((aligned(64))) T[[BASES]] {
+  // PRINT-NEXT:    int i;
+  // PRINT-NEXT:    [[KW]] T *p2;
+  // PRINT-NEXT:    [[KW]] __attribute__((may_alias)) T *p3;
+  // PRINT-NEXT:    [[KW]] T *p4;
+  // PRINT-NEXT:  } *p1;
+  KW __attribute__((aligned(64))) T BASES { // expected-warning {{'T' is deprecated}}
     int i;
     KW T *p2;
+    // FIXME: For C++, T at p3 loses aligned and deprecated, perhaps because
+    // that RecordDecl isn't in the same redecl list.  Perhaps the redecl lists
+    // are split here but not in C due to the different scoping rules in C++
+    // classes.
+    KW __attribute__((may_alias)) T *p3;
+    KW T *p4;
   } *p1;
 
-  // LLVM: store i64 16
+  // LLVM: store i64 64
   long s0 = sizeof *p0;
-  // LLVM-NEXT: store i64 16
+  // LLVM-NEXT: store i64 64
   long s1 = sizeof *p1;
-  // LLVM-NEXT: store i64 16
+  // LLVM-NEXT: store i64 64
   long s2 = sizeof *p0->p2;
-  // LLVM-NEXT: store i64 16
-  long s3 = sizeof *p1->p2;
-  // LLVM-NEXT: store i64 16
-  long s4 = sizeof *p1->p2->p2;
+  // LLVM-NEXT: store i64 64
+  long s3 = sizeof *p1->p3;
+  // LLVM-NEXT: store i64 64
+  long s4 = sizeof *p1->p4->p2;
 }
 
 // CHECK-LABEL: declsOnly
@@ -224,14 +234,41 @@ void inInit() {
 }
 
 #ifdef __cplusplus
-// CXX-LABEL: inMemberPtr
+// PRINT-CXX-LABEL: inMemberPtr
 void inMemberPtr() {
-  // CXX-NEXT: [[KW]] T1 {
-  // CXX-NEXT:   int i;
-  // CXX-NEXT: };
+  // PRINT-CXX-NEXT: [[KW]] T1 {
+  // PRINT-CXX-NEXT:   int i;
+  // PRINT-CXX-NEXT: };
   KW T1 { int i; };
-  // CXX-NEXT: [[KW]] T2 {
-  // CXX-NEXT: } T1::*p;
+  // PRINT-CXX-NEXT: [[KW]] T2 {
+  // PRINT-CXX-NEXT: } T1::*p;
   KW T2 {} T1::*p;
 }
 #endif
+
+// Check that tag decl groups stay together in decl contexts.
+
+// PRINT-LABEL: DeclGroupAtFileScope {
+// PRINT-NEXT:    int i;
+// PRINT-NEXT:  } *DeclGroupAtFileScopePtr;
+KW DeclGroupAtFileScope { int i; } *DeclGroupAtFileScopePtr;
+
+// PRINT-LABEL: DeclGroupInMemberList {
+KW DeclGroupInMemberList {
+  // PRINT-NEXT:  struct  T1 {
+  // PRINT-NEXT:    int i;
+  // PRINT-NEXT:  } t1;
+  struct T1 { int i; } t1;
+  // PRINT-NEXT:  union T2 {
+  // PRINT-NEXT:    int i;
+  // PRINT-NEXT:  } *t20, t21[2];
+  union T2 { int i; } *t20, t21[2];
+  // PRINT-NEXT:  enum T3 {
+  // PRINT-NEXT:    T30
+  // PRINT-NEXT:  } t30;
+  enum T3 { T30 } t30;
+  // PRINT-NEXT: };
+};
+
+// A tag decl group in the tag decl's own member list is exercised in
+// defSelfRef above.