From: David Chisnall <csdavec@swan.ac.uk>
Date: Fri, 16 Mar 2012 12:15:37 +0000 (+0000)
Subject: Warn on flexible array members when in C89 mode, with -pedantic.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0961a01ebec0e31664bfe464bf4a0ac7b0891a1f;p=clang

Warn on flexible array members when in C89 mode, with -pedantic.
This fixes PR 4307.

Patch by Eitan Adler!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152918 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticParseKinds.td b/include/clang/Basic/DiagnosticParseKinds.td
index 95522189e1..1f03a0777c 100644
--- a/include/clang/Basic/DiagnosticParseKinds.td
+++ b/include/clang/Basic/DiagnosticParseKinds.td
@@ -56,6 +56,8 @@ def ext_c99_variable_decl_in_for_loop : Extension<
   "variable declaration in for loop is a C99-specific feature">, InGroup<C99>;
 def ext_c99_compound_literal : Extension<
   "compound literals are a C99-specific feature">, InGroup<C99>;
+def ext_c99_flexible_array_member : Extension<
+  "Flexible array members are a C99-specific feature">, InGroup<C99>;
 def ext_enumerator_list_comma : Extension<
   "commas at the end of enumerator lists are a %select{C99|C++11}0-specific "
   "feature">;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index ab1a1b4025..574c18c2e3 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -9483,6 +9483,13 @@ void Sema::ActOnFields(Scope* S,
         else if (Fields.size() == 1) 
           Diag(FD->getLocation(), diag::ext_flexible_array_empty_aggregate_gnu)
             << FD->getDeclName() << Record->getTagKind();
+      } else if (!getLangOpts().C99) {
+      if (Record->isUnion())
+        Diag(FD->getLocation(), diag::ext_flexible_array_union_gnu)
+          << FD->getDeclName();
+      else
+        Diag(FD->getLocation(), diag::ext_c99_flexible_array_member)
+          << FD->getDeclName() << Record->getTagKind();
       } else if (NumNamedMembers < 1) {
         Diag(FD->getLocation(), diag::err_flexible_array_empty_struct)
           << FD->getDeclName();
diff --git a/test/Sema/c89.c b/test/Sema/c89.c
index ac8c6e0b7b..25a10481e9 100644
--- a/test/Sema/c89.c
+++ b/test/Sema/c89.c
@@ -90,4 +90,6 @@ void test16() {
   printg("Hello, world!\n"); /* expected-warning {{implicit declaration of function 'printg'}} */
 }
 
+struct x { int x,y[]; }; /* expected-warning {{Flexible array members are a C99-specific feature}} */
+
 void main() {} /* expected-error {{'main' must return 'int'}} */