target-def.h (TARGET_CXX_EXPORT_CLASS_DATA): Remove.

	* target-def.h (TARGET_CXX_EXPORT_CLASS_DATA): Remove.
	(TARGET_CXX_DETERMINE_CLASS_VISIBILITY): New macro.
	(TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT): Likewise.
	(TARGET_CXX): Adjust accordingly.
	* target.h (struct gcc_target): Remove epxort_class_data.  Add
	determine_class_data_visibility and class_data_always_comdat.
	* doc/tm.texi (TARGET_CXX_EXPORT_CLASS_DATA): Remove.
	(TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY): Document.
	(TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT): Likewise.
	* config/arm/arm.c (arm_cxx_export_class_data): Remove.
	(arm_cxx_determine_class_data_visibility): New.
	(arm_cxx_class_data_always_comdat): Likewise.
	(TARGET_CXX_EXPORT_CLASS_DATA): Remove.
	(TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY): Define.
	(TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT): Likewise.
	* config/arm/arm.h (TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P): Define.
	* config/arm/symbian.h (TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P):
	Define.

	* decl2.c (determine_visibility): Don't use export_class_data.
	(import_export_decl): Honor TARGET_CXX_CLASS_DATA_ALWAYS_WEAK and
	TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY.

	* testsuite/g++.dg/ext/visibility/arm2.C: New test.
	* testsuite/g++.dg/ext/visibility/arm3.C: Likewise.
	* testsuite/g++.dg/ext/visibility/symbian2.C: Likewise.

From-SVN: r98010

3 files changed, 37 insertions, 9 deletions

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 5091f8e..b713bff 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -172,7 +172,8 @@ static tree arm_get_cookie_size (tree);
 static bool arm_cookie_has_size (void);
 static bool arm_cxx_cdtor_returns_this (void);
 static bool arm_cxx_key_method_may_be_inline (void);
-static bool arm_cxx_export_class_data (void);
+static void arm_cxx_determine_class_data_visibility (tree);
+static bool arm_cxx_class_data_always_comdat (void);
 static void arm_init_libfuncs (void);
 static unsigned HOST_WIDE_INT arm_shift_truncation_mask (enum machine_mode);
 
@@ -307,8 +308,12 @@ static unsigned HOST_WIDE_INT arm_shift_truncation_mask (enum machine_mode);
 #undef TARGET_CXX_KEY_METHOD_MAY_BE_INLINE
 #define TARGET_CXX_KEY_METHOD_MAY_BE_INLINE arm_cxx_key_method_may_be_inline
 
-#undef TARGET_CXX_EXPORT_CLASS_DATA
-#define TARGET_CXX_EXPORT_CLASS_DATA arm_cxx_export_class_data
+#undef TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY
+#define TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY \
+  arm_cxx_determine_class_data_visibility
+
+#undef TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT
+#define TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT arm_cxx_class_data_always_comdat
 
 struct gcc_target targetm = TARGET_INITIALIZER;
 
@@ -14318,15 +14323,28 @@ arm_cxx_key_method_may_be_inline (void)
   return !TARGET_AAPCS_BASED;
 }
 
-/* The EABI says that the virtual table, etc., for a class must be
-   exported if it has a key method.  The EABI does not specific the
-   behavior if there is no key method, but there is no harm in
-   exporting the class data in that case too.  */
+static void
+arm_cxx_determine_class_data_visibility (tree decl)
+{
+  if (!TARGET_AAPCS_BASED)
+    return;
 
+  /* In general, \S 3.2.5.5 of the ARM EABI requires that class data
+     is exported.  However, on systems without dynamic vague linkage,
+     \S 3.2.5.6 says that COMDAT class data has hidden linkage.  */
+  if (!TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P && DECL_COMDAT (decl))
+    DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
+  else
+    DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
+  DECL_VISIBILITY_SPECIFIED (decl) = 1;
+}
+  
 static bool
-arm_cxx_export_class_data (void)
+arm_cxx_class_data_always_comdat (void)
 {
-  return TARGET_AAPCS_BASED;
+  /* \S 3.2.5.4 of the ARM C++ ABI says that class data only have
+     vague linkage if the class has no key function.  */
+  return !TARGET_AAPCS_BASED;
 }
 
 void
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 59ad92a..5955a52 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -2108,6 +2108,12 @@ typedef struct
 #define ASM_OUTPUT_LABELREF(FILE, NAME)		\
    arm_asm_output_labelref (FILE, NAME)
 
+/* True if the operating system can merge entities with vague linkage
+   (e.g., symbols in COMDAT group) during dynamic linking.  */
+#ifndef TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P
+#define TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P true
+#endif
+
 /* Set the short-call flag for any function compiled in the current
    compilation unit.  We skip this for functions with the section
    attribute when long-calls are in effect as this tells the compiler
diff --git a/gcc/config/arm/symbian.h b/gcc/config/arm/symbian.h
index 2a588ed..5ea3fa7 100644
--- a/gcc/config/arm/symbian.h
+++ b/gcc/config/arm/symbian.h
@@ -87,3 +87,7 @@
       builtin_define ("__symbian__");		\
     }						\
   while (false)
+
+
+/* SymbianOS cannot merge entities with vague linkage at runtime.  */
+#define TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P false