crypto/tls: force OS X target version to 10.6 for API compatibility

This is a band-aid until we can use weak imports with cgo.

Fixes #3131.

R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/5700083

diff --git a/src/pkg/crypto/tls/root_darwin.go b/src/pkg/crypto/tls/root_darwin.go
index db1b18b3c07dc7af2868de2dabec1a6bc0edb14a..911a9a62e3cc160e77ed52f54eb4d4863b39aedc 100644 (file)
--- a/src/pkg/crypto/tls/root_darwin.go
+++ b/src/pkg/crypto/tls/root_darwin.go
@@ -5,11 +5,9 @@
 package tls
 
 /*
-// Note: We disable -Werror here because the code in this file uses a deprecated API to stay
-// compatible with both Mac OS X 10.6 and 10.7. Using a deprecated function on Darwin generates
-// a warning.
-#cgo CFLAGS: -Wno-error -Wno-deprecated-declarations
+#cgo CFLAGS: -mmacosx-version-min=10.6 -D__MAC_OS_X_VERSION_MAX_ALLOWED=1060
 #cgo LDFLAGS: -framework CoreFoundation -framework Security
+
 #include <CoreFoundation/CoreFoundation.h>
 #include <Security/Security.h>
 
@@ -40,26 +38,12 @@ int FetchPEMRoots(CFDataRef *pemRoots) {
                        continue;
                }
 
-               // SecKeychainImportExport is deprecated in >= OS X 10.7, and has been replaced by
-               // SecItemExport.  If we're built on a host with a Lion SDK, this code gets conditionally
-               // included in the output, also for binaries meant for 10.6.
-               //
-               // To make sure that we run on both Mac OS X 10.6 and 10.7 we use weak linking
-               // and check whether SecItemExport is available before we attempt to call it. On
-               // 10.6, this won't be the case, and we'll fall back to calling SecKeychainItemExport.
-#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
-               if (SecItemExport) {
-                       err = SecItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
-                       if (err != noErr) {
-                               continue;
-                       }
-               } else
-#endif
-               if (data == NULL) {
-                       err = SecKeychainItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
-                       if (err != noErr) {
-                               continue;
-                       }
+               // Note: SecKeychainItemExport is deprecated as of 10.7 in favor of SecItemExport.
+               // Once we support weak imports via cgo we should prefer that, and fall back to this
+               // for older systems.
+               err = SecKeychainItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
+               if (err != noErr) {
+                       continue;
                }
 
                if (data != NULL) {