[PATCH] [libcxx] Mark local printf variants as _LIBCPP_HIDDEN to prevent them from becoming part of the DSO.

[Eric Fiselier]

Hi mclow.lists, danalbert,

This patch marks 3 symbols as hidden. The symbols are:

1. ZNSt3__110__sscanf_lEPKcP15__locale_structS1_z
2. _ZNSt3__112__asprintf_lEPPcP15__locale_structPKcz
3. _ZNSt3__112__snprintf_lEPcmP15__locale_structPKcz

I used `_LIBCPP_HIDDEN` as opposed to `_LIBCPP_INLINE_VISIBILITY` because 
varargs functions cannot be inlined.

I used sym_check to ensure that these symbols are not already present in the 
system libraries for OS X 10.10 and FreeBSD 10.1. I don't know of any other 
platforms that require strict ABI compatibility. Playstation perhaps?

@danalbert: Will this change affect android? Can you check to see if these 
symbols have been shipped?

On linux these symbols are spuriously emitted into the DSO depending on the 
optimisation level.

See 
http://ds2.efcs.ca:8080/builders/abi-checker-debug/builds/5/steps/test.libcxx.abi.release/logs/stdio
 for an example of this problem.

http://reviews.llvm.org/D8651

Files:
  include/locale

Index: include/locale
===================================================================
--- include/locale
+++ include/locale
@@ -368,7 +368,7 @@
 #endif
 }
 
-inline
+inline _LIBCPP_HIDDEN
 int __snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, 
...) {
   va_list __va;
   va_start(__va, __format);
@@ -382,7 +382,7 @@
   return __res;
 }
 
-inline
+inline _LIBCPP_HIDDEN
 int __asprintf_l(char **__s, locale_t __l, const char *__format, ...) {
   va_list __va;
   va_start(__va, __format);
@@ -396,7 +396,7 @@
   return __res;
 }
 
-inline
+inline _LIBCPP_HIDDEN
 int __sscanf_l(const char *__s, locale_t __l, const char *__format, ...) {
   va_list __va;
   va_start(__va, __format);

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/

Index: include/locale
===================================================================
--- include/locale
+++ include/locale
@@ -368,7 +368,7 @@
 #endif
 }
 
-inline
+inline _LIBCPP_HIDDEN
 int __snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...) {
   va_list __va;
   va_start(__va, __format);
@@ -382,7 +382,7 @@
   return __res;
 }
 
-inline
+inline _LIBCPP_HIDDEN
 int __asprintf_l(char **__s, locale_t __l, const char *__format, ...) {
   va_list __va;
   va_start(__va, __format);
@@ -396,7 +396,7 @@
   return __res;
 }
 
-inline
+inline _LIBCPP_HIDDEN
 int __sscanf_l(const char *__s, locale_t __l, const char *__format, ...) {
   va_list __va;
   va_start(__va, __format);

_______________________________________________
cfe-commits mailing list
cfe-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits