[libpng17] Corrected Android builds and corrected libpng.vers with symbol

prefixing. This adds an API to set optimization options externally,
providing an alternative and general solution for the non-portable
run-time tests used by the ARM Neon code.  It also makes those tests
compile and link on Android.  The order of settings vs options in
pnglibconf.h is reversed to allow settings to depend on options and
options can now set (or override) the defaults for settings.

1 files changed, 32 insertions, 16 deletions

diff --git a/arm/arm_init.c b/arm/arm_init.c
index 78750d6a4..1e7b9981c 100644
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@@ -16,16 +16,7 @@
 
 #include "../pngpriv.h"
 
-#if defined(PNG_FILTER_OPTIMIZATIONS) && defined(__arm__) && \
-   defined(__ARM_NEON__)
-/* __arm__ is defined by GCC, MSVC defines _M_ARM to the ARM version number,
- * Andoid intends to define __ANDROID__, however there are bugs in their
- * toolchain; use -D__ANDROID__ to work round this.
- *
- * __ARM_NEON__ is used to ensure that the compiler has the appropriate ARM
- * NEON support
- */
-
+#ifdef PNG_ARM_NEON_SUPPORTED
 #ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
 #include <signal.h> /* for sig_atomic_t */
 
@@ -45,7 +36,8 @@ png_have_neon(png_structp png_ptr)
     * implemented as below, therefore it is better to cache the result (these
     * function calls may be slow!)
     */
-   return andoid_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
+   PNG_UNUSED(png_ptr)
+   return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
       (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
 }
 #elif defined(__linux__)
@@ -161,15 +153,39 @@ png_have_neon(png_structp png_ptr)
 void
 png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
 {
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+   switch ((pp->options >> PNG_ARM_NEON) & 3)
+   {
+      case PNG_OPTION_UNSET:
+         /* Allow the run-time check to execute if it has been enabled -
+          * thus both API and CHECK can be turned on.  If it isn't supported
+          * this case will fall through to the 'default' below, which just
+          * returns.
+          */
+#endif /* PNG_ARM_NEON_API_SUPPORTED */
 #ifdef PNG_ARM_NEON_CHECK_SUPPORTED
-   static volatile sig_atomic_t no_neon = -1; /* not checked */
+         {
+            static volatile sig_atomic_t no_neon = -1; /* not checked */
 
-   if (no_neon < 0)
-      no_neon = !png_have_neon(pp);
+            if (no_neon < 0)
+               no_neon = !png_have_neon(pp);
 
-   if (no_neon)
-      return;
+            if (no_neon)
+               return;
+         }
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+         break;
+#endif
 #endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+      case PNG_OPTION_ON:
+         /* Option turned on */
+         break;
+
+      default: /* OFF or INVALID */
+         return;
+   }
+#endif
 
    /* IMPORTANT: any new external functions used here must be declared using
     * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the