PNaCl driver: Add libgcc to mixed native/bitcode links

pnacl/driver/driver_env.py

Index: pnacl/driver/driver_env.py
diff --git a/pnacl/driver/driver_env.py b/pnacl/driver/driver_env.py
index 043fefe95191c94af6e9d22f4ce0043c4e06bb30..3cae697f1f3ac0a9c7b9fddb8f43387b31af7b44 100755
--- a/pnacl/driver/driver_env.py
+++ b/pnacl/driver/driver_env.py
@@ -50,6 +50,14 @@ INITIAL_ENV = {
   'BASE_LIB_X8664'  : '${BASE}/lib-bc-x86-64',
   'BASE_LIB_ARM'    : '${BASE}/lib-bc-arm',
 
+  'LIBS_NATIVE_ARCH' : '${LIBS_NATIVE_%ARCH%}',
+  'LIBS_NATIVE_ARM' : '${BASE_LIB_NATIVE}arm',
+  'LIBS_NATIVE_ARM_NONSFI' : '${BASE_LIB_NATIVE}arm-nonsfi',
+  'LIBS_NATIVE_X8632' : '${BASE_LIB_NATIVE}x86-32',
+  'LIBS_NATIVE_X8632_NONSFI' : '${BASE_LIB_NATIVE}x86-32-nonsfi',
+  'LIBS_NATIVE_X8664' : '${BASE_LIB_NATIVE}x86-64',
+  'LIBS_NATIVE_MIPS32' : '${BASE_LIB_NATIVE}mips32',
+
   'BASE_LLVM_BIN'   : '${BASE_LLVM}/bin',
   'TRANSLATOR_BIN'  :
     '${BASE_TOOLCHAIN}/pnacl_translator/${STANDARD_ARCH}/bin',
@@ -207,6 +215,23 @@ def FindFirst(s, pos, strset):
   pos = min(m)
   return (m[pos], pos)
 
+# Find the first instance of a terminating character, skipping over nested
+# brace expressions.
+def FindTerm(s, pos, terminators):
+  depth = 0
+  end = pos
+  for c in s[pos:]:
+    if c == '{':
+      depth += 1
+    elif depth > 0 and c == '}':
+      depth -= 1
+    else:
+      for t in terminators:
+        if s.find(t, end) == end:
+          return end
+    end += 1
+  return end
+
 class Environment(object):
   functions = {}
 
@@ -467,12 +492,22 @@ class Environment(object):
       (is_cond_true,i) = self.eval_bool_expr(s, pos, ['?']+terminators)
       assert(i < len(s) and s[i] == '?')
 
-      (if_true_expr, j) = self.eval_expr(s, i+1, [' : ']+terminators)
+      if is_cond_true:
+        (if_true_expr, j) = self.eval_expr(s, i+1, [' : ']+terminators)
+      else:
+        # Don't evaluate the expr (it won't be used), just find its end.
+        assert terminators[0] == '}'
+        j = FindTerm(s, i+1, [' : '] + terminators)
       if j == len(s):
         return ('', j) # Error one level up
 
       if s[j:j+3] == ' : ':
-        (if_false_expr,j) = self.eval_expr(s, j+3, terminators)
+        if not is_cond_true:
+          (if_false_expr,j) = self.eval_expr(s, j+3, terminators)
+        else:
+          # Don't evaluate the expr (it won't be used), just find its end.
+          assert terminators[0] == '}'
+          j = FindTerm(s, j + 3, terminators)
         if j == len(s):
           # This is an error condition one level up.
           return ('', j)