Refactor get_string_constant function into string_ptr context method

LlvmGenerator.py

@@ -178,6 +178,18 @@ class Context():
         struct = decl_struct(['nCount', 'arr'], [ctx.i32, arr_ty], name)
         return struct.ty
 
+    def string_ptr(self, str):
+        ''' Returns a pointer to a global string with the given value '''
+        if str in self.strings:
+            return self.strings[str].gep([self.zero, self.zero])
+
+        str_val = core.Constant.stringz(str)
+        var_name = '.str%s' % len(self.strings)
+        var_ptr = self.module.add_global_variable(str_val.type, var_name)
+        var_ptr.initializer = str_val
+        self.strings[str] = var_ptr
+        return var_ptr.gep([self.zero, self.zero])
+
 
 class StructType():
     def __init__(self, name, field_names, field_types):
@@ -488,25 +500,20 @@ def generate_write(params):
         expr_val = expression(param)
 
         if basic_ty.kind in ['IntegerType', 'Integer32Type']:
-            fmt_val = get_string_cons('% d')
-            fmt_ptr = ctx.builder.gep(fmt_val, [ctx.zero, ctx.zero])
-            ctx.builder.call(ctx.funcs['printf'], [fmt_ptr, expr_val])
+            fmt_str_ptr = ctx.string_ptr('% d')
+            ctx.builder.call(ctx.funcs['printf'], [fmt_str_ptr, expr_val])
         elif basic_ty.kind == 'RealType':
-            fmt_val = get_string_cons('% .14E')
-            fmt_ptr = ctx.builder.gep(fmt_val, [ctx.zero, ctx.zero])
-            ctx.builder.call(ctx.funcs['printf'], [fmt_ptr, expr_val])
+            fmt_str_ptr = ctx.string_ptr('% .14E')
+            ctx.builder.call(ctx.funcs['printf'], [fmt_str_ptr, expr_val])
         elif basic_ty.kind == 'BooleanType':
-            true_str_val = get_string_cons('TRUE')
-            true_str_ptr = ctx.builder.gep(true_str_val, [ctx.zero, ctx.zero])
-            false_str_val = get_string_cons('FALSE')
-            false_str_ptr = ctx.builder.gep(false_str_val, [ctx.zero, ctx.zero])
+            true_str_ptr = ctx.string_ptr('TRUE')
+            false_str_ptr = ctx.string_ptr('FALSE')
             str_ptr = ctx.builder.select(expr_val, true_str_ptr, false_str_ptr)
             ctx.builder.call(ctx.funcs['printf'], [str_ptr])
         elif basic_ty.kind in ['StringType', 'OctetStringType']:
-            fmt_val = get_string_cons('%s')
-            fmt_ptr = ctx.builder.gep(fmt_val, [ctx.zero, ctx.zero])
+            fmt_str_ptr = ctx.string_ptr('%s')
             arr_ptr = ctx.builder.gep(expr_val, [ctx.zero, ctx.one])
-            ctx.builder.call(ctx.funcs['printf'], [fmt_ptr, arr_ptr])
+            ctx.builder.call(ctx.funcs['printf'], [fmt_str_ptr, arr_ptr])
         else:
             raise NotImplementedError
 
@@ -515,9 +522,7 @@ def generate_writeln(params):
     ''' Generate the code for the writeln operator '''
     generate_write(params)
 
-    zero = core.Constant.int(ctx.i32, 0)
-    str_cons = get_string_cons('\n')
-    str_ptr = ctx.builder.gep(str_cons, [zero, zero])
+    str_ptr = ctx.string_ptr('\n')
     ctx.builder.call(ctx.funcs['printf'], [str_ptr])
 
 
@@ -1065,8 +1070,7 @@ def _empty_string(primary):
 @expression.register(ogAST.PrimStringLiteral)
 def _string_literal(primary):
     ''' Generate code for a string (Octet String) '''
-    str_val = get_string_cons(str(primary.value[1:-1]))
-    str_ptr = ctx.builder.gep(str_val, [ctx.zero, ctx.zero])
+    str_ptr = ctx.string_ptr(str(primary.value[1:-1]))
 
     # Allocate anonymous OctetString struct
     str_len = len(str(primary.value[1:-1])) + 1
@@ -1386,19 +1390,6 @@ def _inner_procedure(proc):
     func.verify()
 
 
-def get_string_cons(str):
-    ''' Returns a reference to a global string constant with the given value '''
-    if str in ctx.strings:
-        return ctx.strings[str]
-
-    str_val = core.Constant.stringz(str)
-    gvar_name = '.str%s' % len(ctx.strings)
-    gvar_val = ctx.module.add_global_variable(str_val.type, gvar_name)
-    gvar_val.initializer = str_val
-    ctx.strings[str] = gvar_val
-    return gvar_val
-
-
 def decl_func(name, return_ty, param_tys, extern=False):
     ''' Declare a function '''
     func_ty = core.Type.function(return_ty, param_tys)