Typechecking for int, long types

Refactored files to /analyze folder

1 files changed, 0 insertions, 657 deletions

diff --git a/src/cljcc/analyzer.clj b/src/cljcc/analyzer.clj
deleted file mode 100644
index fbdc131..0000000
--- a/src/cljcc/analyzer.clj
+++ /dev/null
@@ -1,657 +0,0 @@
-(ns cljcc.analyzer
-  (:require [cljcc.lexer :as l]
-            [cljcc.util :as u]
-            [cljcc.parser :as p]
-            [cljcc.exception :as exc]))
-
-(defn- unique-identifier
-  ([] (unique-identifier "analyzer"))
-  ([identifier] (u/create-identifier! identifier)))
-
-(defn- copy-identifier-map
-  "Returns a copy of the identifier map.
-
-  Sets :at-top-level false, as it's going inside a scope. ( Could be fn definition, compound statement ).
-  Sets :from-current-scope as false for every symbol. Used when going into a inner scope."
-  [ident->symbol]
-  (let [set-from-current-scope-as-false (fn [i->s]
-                                          (zipmap (keys i->s)
-                                                  (map (fn [s]
-                                                         (assoc s :from-current-scope false))
-                                                       (vals i->s))))]
-    (-> ident->symbol
-        (dissoc :at-top-level)
-        set-from-current-scope-as-false
-        (assoc :at-top-level false))))
-
-(declare resolve-block)
-
-(defn- resolve-exp [e ident->symbol]
-  (condp = (:exp-type e)
-    :constant-exp e
-    :variable-exp (if (contains? ident->symbol (:identifier e))
-                    (p/variable-exp-node (:name (get ident->symbol (:identifier e))))
-                    (exc/analyzer-error "Undeclared variable seen." {:variable e}))
-    :assignment-exp (let [left (:left e)
-                          right (:right e)
-                          op (:assignment-operator e)
-                          left-var? (= :variable-exp (:exp-type left))]
-                      (if left-var?
-                        (p/assignment-exp-node (resolve-exp left ident->symbol)
-                                               (resolve-exp right ident->symbol)
-                                               op)
-                        (exc/analyzer-error "Invalid lvalue in assignment expression." {:lvalue e})))
-    :binary-exp (p/binary-exp-node (resolve-exp (:left e) ident->symbol)
-                                   (resolve-exp (:right e) ident->symbol)
-                                   (:binary-operator e))
-    :unary-exp (p/unary-exp-node (:unary-operator e) (resolve-exp (:value e) ident->symbol))
-    :conditional-exp (p/conditional-exp-node (resolve-exp (:left e) ident->symbol)
-                                             (resolve-exp (:middle e) ident->symbol)
-                                             (resolve-exp (:right e) ident->symbol))
-    :cast-exp (p/cast-exp-node (:target-type e)
-                               (resolve-exp (:value e)))
-    :function-call-exp (let [fn-name (:identifier e)
-                             args (:arguments e)]
-                         (if (contains? ident->symbol fn-name)
-                           (p/function-call-exp-node (:new-name (get ident->symbol fn-name))
-                                                     (map #(resolve-exp % ident->symbol) args))
-                           (throw (ex-info "Undeclared function !" {:function-name fn-name}))))
-    (exc/analyzer-error "Invalid expression." {:exp e})))
-
-(defn- resolve-optional-exp [e identifier-map]
-  (if (nil? e)
-    e
-    (resolve-exp e identifier-map)))
-
-(defn- resolve-file-scope-variable-declaration
-  "Adds file scope variable declaration to scope.
-
-  Directly adds variable declaration to map as it is top level."
-  [{:keys [identifier] :as declaration} ident->symbol]
-  {:declaration declaration
-   :ident->symbol (assoc ident->symbol identifier {:new-name identifier
-                                                   :name identifier
-                                                   :from-current-scope true
-                                                   :has-linkage true})})
-
-(defn- resolve-local-variable-declaration
-  "Add local variable declaration.
-
-  Validates for variables declared with same name.
-  Validates for variables declared from different scope, but with conflicting storage class."
-  [{:keys [identifier initial storage-class] :as declaration} ident->symbol]
-  (let [prev-entry (get ident->symbol identifier)
-        extern? (= storage-class :extern)
-        _ (when (and prev-entry (:from-current-scope prev-entry))
-            (when (not (and (:has-linkage prev-entry) extern?))
-              (exc/analyzer-error "Conflicting local declaration." {:declaration declaration})))]
-    (if extern?
-      {:declaration declaration
-       :ident->symbol (assoc ident->symbol identifier {:new-name identifier
-                                                       :name identifier
-                                                       :from-current-scope true
-                                                       :has-linkage true})}
-      (let [unique-name (unique-identifier identifier)
-            updated-symbols (assoc ident->symbol identifier {:new-name unique-name
-                                                             :name unique-name
-                                                             :from-current-scope true
-                                                             :has-linkage false})
-            init-value (when initial (resolve-exp initial updated-symbols))]
-        {:declaration (p/variable-declaration-node unique-name storage-class init-value)
-         :ident->symbol updated-symbols}))))
-
-(defn- resolve-variable-declaration
-  "Resolves variable declarations.
-
-  Ensures variable not declared twice in the current scope."
-  [decl {:keys [at-top-level] :as ident->symbol}]
-  (if at-top-level
-    (resolve-file-scope-variable-declaration decl ident->symbol)
-    (resolve-local-variable-declaration decl ident->symbol)))
-
-(defn- resolve-parameter [{:keys [identifier] :as param} ident->symbol]
-  (if (and (contains? ident->symbol identifier)
-           (:from-current-scope (get ident->symbol identifier)))
-    (exc/analyzer-error "Parameter name duplicated." {:parameter param})
-    (let [unique-name (unique-identifier identifier)
-          storage-class nil
-          updated-identifier-map (assoc ident->symbol identifier {:name unique-name
-                                                                  :from-current-scope true
-                                                                  :has-linkage false})]
-      {:parameter (p/variable-declaration-node unique-name storage-class)
-       :ident->symbol updated-identifier-map})))
-
-(defn- resolve-parameters [params ident->symbol]
-  (reduce (fn [acc p]
-            (let [{:keys [parameter ident->symbol]} (resolve-parameter p (:ident->symbol acc))]
-              {:parameters (conj (:parameters acc) parameter)
-               :ident->symbol ident->symbol}))
-          {:parameters [] :ident->symbol ident->symbol}
-          params))
-
-(defn- resolve-function-declaration
-  "Resolve function declaration.
-
-  Ensures functions not declared twice in current scope with incorrect linkage."
-  [{:keys [identifier storage-class parameters return-type body] :as d} ident->symbol]
-  (let [prev-entry (get ident->symbol identifier)
-        already-declared-var? (and (contains?  ident->symbol identifier)
-                                   (:from-current-scope (get ident->symbol identifier))
-                                   (not (:has-linkage prev-entry)))
-        illegally-redeclared? (and (contains? ident->symbol identifier)
-                                   (:from-current-scope prev-entry)
-                                   (not (:has-linkage prev-entry)))
-        static? (= :static storage-class)
-        inside-function-definition? (not (:at-top-level ident->symbol))
-        _ (when already-declared-var?
-            (exc/analyzer-error "Variable already declared in same scope." {:declaration d}))
-        _ (when illegally-redeclared?
-            (exc/analyzer-error "Function duplicate declaration." {:declaration d}))
-        updated-identifier-map (assoc ident->symbol identifier {:new-name identifier
-                                                                :name identifier
-                                                                :from-current-scope true
-                                                                :has-linkage true})
-        inner-map (copy-identifier-map updated-identifier-map)
-        {new-params :parameters, inner-map :ident->symbol} (resolve-parameters parameters inner-map)
-        _ (when (and body inside-function-definition?)
-            (exc/analyzer-error "Nested function definition not allowed." {:declaration d
-                                                                           :ident->symbol ident->symbol}))
-        _ (when (and inside-function-definition? static?)
-            (exc/analyzer-error "Nested static function declarations cannot exist." {:declaration d}))
-        new-body (when body (resolve-block body inner-map))]
-    {:declaration (p/function-declaration-node return-type storage-class identifier new-params (:block new-body))
-     :ident->symbol updated-identifier-map}))
-
-(defn- resolve-declaration [{:keys [declaration-type] :as d} ident->symbol]
-  (condp = declaration-type
-    :variable (resolve-variable-declaration d ident->symbol)
-    :function (resolve-function-declaration d ident->symbol)
-    (throw (ex-info "Analyzer Error. Invalid declaration type." {:declaration d}))))
-
-(defn- resolve-for-init [for-init ident->symbol]
-  (if (= (:type for-init) :declaration)
-    (resolve-declaration for-init ident->symbol)
-    (resolve-optional-exp for-init ident->symbol)))
-
-(defmulti resolve-statement
-  "Resolves statements in a given scope.
-
-  Scope here refers to the ident->symbol map, which holds declarations
-  visisble to statement at this time.
-
-  Dispatches based on the type of statement.
-
-  Returns statement after recursively resolving all expressions and statements.
-  "
-  (fn [statement _ident->symbol]
-    (:statement-type statement)))
-
-(defmethod resolve-statement :default [statement _]
-  (exc/analyzer-error "Invalid statement." {:statement statement}))
-
-(defmethod resolve-statement :return [{:keys [value]} ident->symbol]
-  (p/return-statement-node (resolve-exp value ident->symbol)))
-
-(defmethod resolve-statement :break [statement _]
-  statement)
-
-(defmethod resolve-statement :continue [statement _]
-  statement)
-
-(defmethod resolve-statement :empty [statement _]
-  statement)
-
-(defmethod resolve-statement :expression [{:keys [value]} ident->symbol]
-  (p/expression-statement-node (resolve-exp value ident->symbol)))
-
-(defmethod resolve-statement :if [{:keys [condition then-statement else-statement]} ident->symbol]
-  (if else-statement
-    (p/if-statement-node (resolve-exp condition ident->symbol)
-                         (resolve-statement then-statement ident->symbol)
-                         (resolve-statement else-statement ident->symbol))
-    (p/if-statement-node (resolve-exp condition ident->symbol)
-                         (resolve-statement then-statement ident->symbol))))
-
-(defmethod resolve-statement :while [{:keys [condition body]} ident->symbol]
-  (p/while-statement-node (resolve-exp condition ident->symbol)
-                          (resolve-statement body ident->symbol)))
-
-(defmethod resolve-statement :do-while [{:keys [condition body]} ident->symbol]
-  (p/do-while-statement-node (resolve-exp condition ident->symbol)
-                             (resolve-statement body ident->symbol)))
-
-(defmethod resolve-statement :for [{:keys [init condition post body]} ident->symbol]
-  (let [for-scope-identifier-map (copy-identifier-map ident->symbol)
-        resolved-for-init (resolve-for-init init for-scope-identifier-map)
-        for-scope-identifier-map (if (:declaration resolved-for-init) ; updates symbol map if for initializer is declaration
-                                   (:ident->symbol resolved-for-init)
-                                   for-scope-identifier-map)
-        resolved-for-init (if (:declaration resolved-for-init) ; getting the underlying declaration, if it is
-                            (:declaration resolved-for-init)
-                            resolved-for-init)
-        condition (resolve-optional-exp condition for-scope-identifier-map)
-        post (resolve-optional-exp post for-scope-identifier-map)
-        body (resolve-statement body for-scope-identifier-map)]
-    (p/for-statement-node resolved-for-init condition post body)))
-
-(defmethod resolve-statement :compound [{:keys [block]} ident->symbol]
-  (p/compound-statement-node (:block (resolve-block block (copy-identifier-map ident->symbol)))))
-
-(defn- resolve-block-item [{:keys [type] :as item} ident->symbol]
-  (condp = type
-    :declaration (let [v (resolve-declaration item ident->symbol)]
-                   {:block-item (:declaration v)
-                    :ident->symbol (:ident->symbol v)})
-    :statement {:block-item (resolve-statement item ident->symbol)
-                :ident->symbol ident->symbol}
-    (exc/analyzer-error "Invalid statement/declaration type." item)))
-
-(defn- resolve-block
-  "Resolves a block with a given symbol table.
-
-  ident->symbol holds identifier to symbol mapping.
-  Symbol contains the type information, generated variable name etc.
-
-  | key            | description |
-  |----------------|-------------|
-  |`:at-top-level` | Is current level top or not ( default true)|"
-  ([block]
-   (resolve-block block {:at-top-level true}))
-  ([block ident->symbol]
-   (reduce (fn [acc block-item]
-             (let [v (resolve-block-item block-item (:ident->symbol acc))]
-               {:block (conj (:block acc) (:block-item v))
-                :ident->symbol (:ident->symbol v)}))
-           {:block []
-            :ident->symbol ident->symbol}
-           block)))
-
-(defn- annotate-label [m l]
-  (assoc m :label l))
-
-(defn- label-statement
-  ([s]
-   (label-statement s nil))
-  ([s current-label]
-   (let [s-type (:statement-type s)]
-     (cond
-       (= s-type :break) (if (nil? current-label)
-                           (throw (ex-info "break statement outside of loop" {}))
-                           (p/break-statement-node current-label))
-       (= s-type :continue) (if (nil? current-label)
-                              (throw (ex-info "continue statement outside of loop" {}))
-                              (p/continue-statement-node current-label))
-       (= s-type :while) (let [new-label (unique-identifier "while_label")
-                               l-body (label-statement (:body s) new-label)
-                               l-while  (p/while-statement-node (:condition s) l-body)]
-                           (annotate-label l-while new-label))
-       (= s-type :do-while) (let [new-label (unique-identifier "do_while_label")
-                                  l-body (label-statement (:body s) new-label)
-                                  l-do-while (p/do-while-statement-node (:condition s) l-body)]
-                              (annotate-label l-do-while new-label))
-       (= s-type :for) (let [new-label (unique-identifier "for_label")
-                             l-body (label-statement (:body s) new-label)
-                             l-for (p/for-statement-node (:init s) (:condition s) (:post s) l-body)]
-                         (annotate-label l-for new-label))
-       (= s-type :if) (if (:else-statement s)
-                        (p/if-statement-node (:condition s)
-                                             (label-statement (:then-statement s) current-label)
-                                             (label-statement (:else-statement s) current-label))
-                        (p/if-statement-node (:condition s)
-                                             (label-statement (:then-statement s) current-label)))
-       (= s-type :compound) (let [update-block-f (fn [item]
-                                                   (if (= (:type item) :statement)
-                                                     (label-statement item current-label)
-                                                     item))
-                                  new-block (map update-block-f (:block s))]
-                              (p/compound-statement-node new-block))
-       (= s-type :return) s
-       (= s-type :expression) s
-       (= s-type :empty) s
-       :else (throw (ex-info "invalid statement reached during loop labelling." {}))))))
-
-(defn- resolve-loop-label [body]
-  (let [f (fn [item]
-            (if (= :statement (:type item))
-              (label-statement item)
-              item))
-        new-body (map f body)]
-    new-body))
-
-(defn- validate-loop-labels [{block :block}]
-  (map (fn [b]
-         (assoc b :body (resolve-loop-label (:body b)))) block))
-
-(defn- typecheck-exp
-  "Returns the expression itself, after typechecking all subexpressions."
-  [{:keys [exp-type] :as e} ident->symbol]
-  (condp = exp-type
-    :constant-exp e
-    :variable-exp (let [identifier (:identifier e)
-                        var? (= :variable (:type (get ident->symbol identifier)))
-                        _ (when (not var?)
-                            (exc/analyzer-error "Function name used as variable." {:exp e :ident->symbol ident->symbol}))]
-                    e)
-    :assignment-exp (do
-                      (typecheck-exp (:left e) ident->symbol)
-                      (typecheck-exp (:right e) ident->symbol)
-                      e)
-    :binary-exp (do
-                  (typecheck-exp (:left e) ident->symbol)
-                  (typecheck-exp (:right e) ident->symbol)
-                  e)
-    :unary-exp (do
-                 (typecheck-exp (:value e) ident->symbol)
-                 e)
-    :conditional-exp (do
-                       (typecheck-exp (:left e) ident->symbol)
-                       (typecheck-exp (:right e) ident->symbol)
-                       (typecheck-exp (:middle e) ident->symbol)
-                       e)
-    :function-call-exp (let [symbol (ident->symbol (:identifier e))
-                             _ (when (not= :function (:type symbol))
-                                 (throw (ex-info "Analyzer Error. Variable used as function name." {:exp e})))
-                             _ (when (not= (count (:arguments e)) (:param-count symbol))
-                                 (throw (ex-info "Analyzer Error. Function called with the wrong number of arguments." {:exp e})))
-                             _ (map #(typecheck-exp % ident->symbol) (:arguments e))]
-                         e)
-    (throw (ex-info "Analyzer error. Invalid expression type passed to typechecker." {:exp e}))))
-
-(defn- fun-attrs [defined? global?]
-  {:type :fun
-   :defined? defined?
-   :global? global?})
-
-(defn- static-attrs [initial-value global?]
-  {:type :static
-   :initial-value initial-value
-   :global? global?})
-
-(defn- local-attrs []
-  {:type :local})
-
-(defn- variable-symbol [variable-type attrs]
-  {:type :variable
-   :variable-type variable-type
-   :attrs attrs})
-
-(defn- function-symbol [param-count attrs]
-  {:type :function
-   :param-count param-count
-   :attrs attrs})
-
-(defn- add-parameters [params ident->symbol]
-  (if (zero? (count params))
-    ident->symbol
-    (apply assoc
-           ident->symbol
-           (flatten (map (fn [p] [(:identifier p) (variable-symbol :int (local-attrs))]) params)))))
-
-(declare typecheck-block)
-
-(defn- validate-fn-decl-and-return-updated-attrs
-  [cur-decl old-decl]
-  (let [param-count (count (:parameters cur-decl))
-        old-param-count (:param-count old-decl)
-        has-body? (seq (:body cur-decl))
-        _ (when (not= param-count old-param-count)
-            (exc/analyzer-error "Incompatible function declarations." {:declaration1 old-decl
-                                                                       :declaration2 cur-decl}))
-        defined? (:defined? (:attrs old-decl))
-        _ (when (and defined? has-body?)
-            (exc/analyzer-error "Function is defined more than once." {:declaration cur-decl}))
-        old-global? (:global? (:attrs old-decl))
-        _ (when (and old-global? (= :static (:storage-class cur-decl)))
-            (exc/analyzer-error "Static function definition follows non static." {:declaration cur-decl}))]
-    {:defined? defined?
-     :global? old-global?}))
-
-(defn- typecheck-function-declaration
-  [{:keys [identifier parameters body storage-class] :as decl} ident->symbol]
-  (let [param-count (count parameters)
-        body? (seq body)
-        old-decl (get ident->symbol identifier)
-        {defined? :defined?
-         global? :global?} (if old-decl
-                             (validate-fn-decl-and-return-updated-attrs decl old-decl)
-                             {:defined? false
-                              :global? (not= :static storage-class)})
-        attrs (fun-attrs (or defined? (boolean body?)) global?)
-        updated-symbol-map (assoc ident->symbol identifier
-                                  (function-symbol param-count attrs))]
-    (if body?
-      (let [with-parameter-symbols (add-parameters parameters updated-symbol-map)
-            with-body-symbols (typecheck-block body (assoc with-parameter-symbols
-                                                           :at-top-level false))]
-        {:declaration decl
-         :ident->symbol (assoc (:ident->symbol with-body-symbols) :at-top-level true)})
-      {:declaration decl
-       :ident->symbol updated-symbol-map})))
-
-(defn- get-initial-value [decl]
-  (cond
-    (= :constant-exp (:exp-type (:initial decl))) {:type :initial
-                                                   :value (:value (:initial decl))}
-    (nil? (:initial decl))    (if (= :extern (:storage-class decl))
-                                {:type :no-initializer}
-                                {:type :tentative})
-    :else (exc/analyzer-error "Non-constant initializer!" decl)))
-
-(defn- validate-file-scope-decl-return-attrs [cur-decl old-decl]
-  (let [_ (when (not= :variable (:type old-decl))
-            (exc/analyzer-error "Function redeclared as variable." {:declaration1 old-decl
-                                                                    :declaration2 cur-decl}))
-        global? (not= :static (:storage-class cur-decl))
-        global? (cond
-                  (= :extern (:storage-class cur-decl)) (:global? (:attrs old-decl))
-                  (not= global? (:global? (:attrs old-decl))) (exc/analyzer-error "Conflicting variable linkage." {:declaration1 old-decl
-                                                                                                                   :declaration2 cur-decl})
-                  :else global?)
-        initial-value (get-initial-value cur-decl)
-        initial-value (cond
-                        (=
-                         :initial
-                         (get-in old-decl [:attrs :initial-value :type])) (if (= (:type initial-value) :initial)
-                                                                            (exc/analyzer-error "Conflivting file scope variable definition." {:declarartion1 old-decl
-                                                                                                                                               :declaration2 cur-decl})
-                                                                            (get-in old-decl [:attrs :initial-value]))
-                        (and
-                         (= :tentative (get-in old-decl [:attrs :initial-value :type]))
-                         (not= :initial (:type initial-value))) {:type :tentative}
-                        :else initial-value)]
-    {:global? global?
-     :initial-value initial-value}))
-
-(defn- typecheck-file-scope-variable-declaration
-  [{:keys [identifier storage-class] :as d} ident->symbol]
-  (let [old-decl (get ident->symbol identifier)
-        global? (not= :static storage-class)
-        initial-value (get-initial-value d)
-        {global? :global?
-         initial-value :initial-value} (if old-decl
-                                         (validate-file-scope-decl-return-attrs d old-decl)
-                                         {:global? global?
-                                          :initial-value initial-value})]
-    {:declaration d
-     :ident->symbol (assoc ident->symbol
-                           identifier
-                           (variable-symbol :int (static-attrs initial-value global?)))}))
-
-(defn- typecheck-local-scope-variable-declaration
-  [{:keys [identifier storage-class initial] :as d} ident->symbol]
-  (cond
-    (= :extern storage-class) (let [_ (when (not (nil? initial))
-                                        (exc/analyzer-error "Initializer on local extern variable declaration." d))
-                                    old-decl (get ident->symbol identifier)
-                                    _ (when (and old-decl (not= :variable (:type old-decl)))
-                                        (exc/analyzer-error "Function redeclared as variable." {:declaration1 old-decl
-                                                                                                :declaration2 d}))
-                                    updated-symbols (if old-decl
-                                                      ident->symbol
-                                                      (assoc ident->symbol
-                                                             identifier
-                                                             (variable-symbol :int (static-attrs {:type :no-initializer} true))))]
-                                {:declaration d
-                                 :ident->symbol updated-symbols})
-    (= :static storage-class) (let [initial-value (cond
-                                                    (= :constant-exp (:exp-type initial)) {:type :initial
-                                                                                           :value (:value initial)}
-                                                    (nil? initial) {:type :initial
-                                                                    :value 0}
-                                                    :else (exc/analyzer-error "Non-constant initializer on local static variable." d))]
-                                {:declaration d
-                                 :ident->symbol (assoc ident->symbol
-                                                       identifier
-                                                       (variable-symbol :int (static-attrs initial-value false)))})
-    :else (let [updated-symbols (assoc ident->symbol identifier (variable-symbol :int (local-attrs)))
-                _ (when initial (typecheck-exp initial updated-symbols))]
-            {:declaration d
-             :ident->symbol updated-symbols})))
-
-(defn- typecheck-declaration [{:keys [declaration-type] :as d} ident->symbol]
-  (let [at-top-level? (:at-top-level ident->symbol)]
-    (condp = declaration-type
-      :variable (if at-top-level?
-                  (typecheck-file-scope-variable-declaration d ident->symbol)
-                  (typecheck-local-scope-variable-declaration d ident->symbol))
-      :function (typecheck-function-declaration d ident->symbol)
-      (throw (ex-info "Analyzer Error. Invalid declaration for typechecker." {:declaration d})))))
-
-(defn- typecheck-optional-expression [e ident->symbol]
-  (if (nil? e)
-    e
-    (typecheck-exp e ident->symbol)))
-
-(defn- typecheck-for-init [for-init ident->symbol]
-  (if (= (:type for-init) :declaration)
-    (typecheck-declaration for-init ident->symbol)
-    (typecheck-optional-expression for-init ident->symbol)))
-
-(defn- typecheck-statement [{:keys [statement-type] :as s} ident->symbol]
-  (condp = statement-type
-    :return (do
-              (typecheck-exp (:value s) ident->symbol)
-              {:statement s
-               :ident->symbol ident->symbol})
-    :expression (do
-                  (typecheck-exp (:value s) ident->symbol)
-                  {:statement s
-                   :ident->symbol ident->symbol})
-    :if (if (:else-statement s)
-          (let
-            [_ (typecheck-exp (:condition s) ident->symbol)
-             {i->s :ident->symbol} (typecheck-statement (:then-statement s) ident->symbol)
-             {i->s :ident->symbol} (typecheck-statement (:else-statement s) i->s)]
-            {:statement s
-             :ident->symbol i->s})
-          (let
-            [_ (typecheck-exp (:condition s) ident->symbol)
-             {i->s :ident->symbol} (typecheck-statement (:then-statement s) ident->symbol)]
-            {:statement s
-             :ident->symbol i->s}))
-    :break {:statement s
-            :ident->symbol ident->symbol}
-    :continue {:statement s
-               :ident->symbol ident->symbol}
-    :while (let
-             [_ (typecheck-exp (:condition s) ident->symbol)
-              {i->s :ident->symbol} (typecheck-statement (:body s) ident->symbol)]
-             {:statement s
-              :ident->symbol i->s})
-    :do-while (let
-                [_ (typecheck-exp (:condition s) ident->symbol)
-                 {i->s :ident->symbol} (typecheck-statement (:body s) ident->symbol)]
-                {:statement s
-                 :ident->symbol i->s})
-    :for (let [f-init (typecheck-for-init (:init s) ident->symbol)
-               updated-symbols (if (:declaration f-init)
-                                 (:ident->symbol f-init)
-                                 ident->symbol)
-               _ (typecheck-optional-expression (:condition s) updated-symbols)
-               _ (typecheck-optional-expression (:post s) updated-symbols)
-               {i->s :ident->symbol} (typecheck-statement (:body s) updated-symbols)]
-           {:statement s
-            :ident->symbol i->s})
-    :compound (let [v (typecheck-block (:block s) ident->symbol)]
-                {:statement s
-                 :ident->symbol (:ident->symbol v)})
-    :empty {:statement s
-            :ident->symbol ident->symbol}
-    (throw (ex-info "Analyzer Error. Invalid statement type in typechecker." {:statement s}))))
-
-(defn- typecheck-item [{:keys [type] :as item} ident->symbol]
-  (condp = type
-    :declaration (let [v (typecheck-declaration item ident->symbol)]
-                   {:block-item (:declaration v)
-                    :ident->symbol (:ident->symbol v)})
-    :statement (let [v (typecheck-statement item ident->symbol)]
-                 {:block-item (:statement v)
-                  :ident->symbol (:ident->symbol v)})
-    (exc/analyzer-error "Invalid statement/declaration." {item item})))
-
-(defn- typecheck-block
-  "Typechecks a block with a given symbol table.
-
-  ident->symbol holds identifier to symbol mapping.
-  Symbol contains the type information, generated variable name etc.
-
-  | key            | description |
-  |----------------|-------------|
-  |`:at-top-level` | Is current level top or not ( default true)|"
-  ([block]
-   (typecheck-block block {:at-top-level true}))
-  ([block ident->symbol]
-   (reduce (fn [acc item]
-             (let [v (typecheck-item item (:ident->symbol acc))]
-               {:block (conj (:block acc) (:block-item v))
-                :ident->symbol (:ident->symbol v)}))
-           {:block []
-            :ident->symbol ident->symbol}
-           block)))
-
-(defn validate [ast]
-  (-> ast
-      resolve-block
-      validate-loop-labels
-      typecheck-block))
-
-(defn- validate-from-src [s]
-  (u/reset-counter!)
-  (-> s
-      l/lex
-      p/parse
-      validate))
-
-(comment
-
-  (validate-from-src
-   "
-int twice(int x){
-    return 2 * x;
-}
-")
-
-  (validate-from-src
-   "
-int static y = 10;
-extern int x = 0;
-
-int main(void) {
-int z = 100;
-return 2;
-}
-")
-
-  (validate-from-src "
-int main(void) {
-    int x = 3;
-    {
-        extern int x;
-    }
-    return x;
-}
-
-static int x = 10;
-")
-
-  ())