diff options
| -rw-r--r-- | src/cljcc/exception.clj | 12 | ||||
| -rw-r--r-- | src/cljcc/lexer.clj | 21 | ||||
| -rw-r--r-- | src/cljcc/parser.clj | 123 |
3 files changed, 102 insertions, 54 deletions
diff --git a/src/cljcc/exception.clj b/src/cljcc/exception.clj index 20d936b..6eec308 100644 --- a/src/cljcc/exception.clj +++ b/src/cljcc/exception.clj @@ -1,7 +1,9 @@ (ns cljcc.exception) -(defn lex-error [{line :line col :col msg :msg}] - (let [err-msg (if (empty? msg) - (format "Lexer error. Invalid token at line: %s, col: %s." line col) - (format "Lexer error. Invalid token at line: %s, col: %s. %s" line col msg))] - (throw (ex-info err-msg {})))) +(defn lex-error [{line :line col :col :as data}] + (throw (ex-info + (format "Invalid token at line: %s, col: %s." line col) + (merge {:error/type :lexer} data)))) + +(defn parser-error [msg data] + (throw (ex-info msg (merge {:error/type :parser} data)))) diff --git a/src/cljcc/lexer.clj b/src/cljcc/lexer.clj index f074ab2..f1b0a2a 100644 --- a/src/cljcc/lexer.clj +++ b/src/cljcc/lexer.clj @@ -1,8 +1,8 @@ (ns cljcc.lexer (:require [cljcc.util :refer [newline? whitespace? read-number digit? letter-digit? letter?]] - [cljcc.token :as t] - [clojure.pprint :as pp])) + [cljcc.exception :as exc] + [cljcc.token :as t])) (defn- lexer-ctx [] {:tokens [] @@ -63,15 +63,18 @@ (recur (apply str rst) npos (-> ctx (update :col #(+ % cnt)) (update :tokens #(conj % token))))) - :else (throw (ex-info "Lexer error. Invalid token." {:line line :col col}))))) + :else (exc/lex-error {:line line :col col})))) (comment - "int main(void) { - return 2; - }" + (lex "int main(void) {return int a = 2; a <<= 2;}") - (pp/pprint - (lex "int main(void) {return int a = 2; a <<= 2;}")) - ()) + (lex " + extern int a; + + int main(void) { + return 42};") + + + ()) diff --git a/src/cljcc/parser.clj b/src/cljcc/parser.clj index 3addc4c..84e681c 100644 --- a/src/cljcc/parser.clj +++ b/src/cljcc/parser.clj @@ -2,17 +2,21 @@ (:require [cljcc.lexer :as l] [cljcc.token :as t] - [clojure.pprint :as pp])) + [cljcc.exception :as exc])) (declare parse parse-exp parse-statement parse-block expect parse-declaration parse-variable-declaration) -(defn- parse-repeatedly [tokens parse-f end-kind] - (loop [tokens tokens - res []] +(defn- parse-repeatedly + "Repeatedly runs given parse function on input until end-kind encountered. + + `parse-f` must return result in form [node remaining-tokens]." + [tokens parse-f end-kind] + (loop [res [] + tokens tokens] (if (= end-kind (:kind (first tokens))) [res tokens] (let [[node rst] (parse-f tokens)] - (recur rst (conj res node)))))) + (recur (conj res node) rst))))) (defn- parse-optional-expression [[{kind :kind} :as tokens] parse-f end-kind] (if (= kind end-kind) @@ -250,14 +254,18 @@ [(do-while-statement-node e s) tokens])) (defn- parse-for-init-statement [[{kind :kind} :as tokens]] - (if (= kind :kw-int) - (parse-variable-declaration tokens) + (if (contains? #{:kw-int :kw-static :kw-extern} kind) + (parse-declaration tokens) (parse-optional-expression tokens parse-exp :semicolon))) (defn- parse-for-statement [tokens] (let [[_ tokens] (expect :kw-for tokens) [_ tokens] (expect :left-paren tokens) [for-init-node tokens] (parse-for-init-statement tokens) + _ (when (= :function (:declaration-type for-init-node)) + (exc/parser-error "Function declaration used in initializer node." for-init-node)) + _ (when-not (nil? (:storage-class for-init-node)) + (exc/parser-error "For initializer cannot contain storage class specifier." for-init-node)) [cond-exp tokens] (parse-optional-expression tokens parse-exp :semicolon) [post-exp tokens] (parse-optional-expression tokens parse-exp :right-paren) [stmt tokens] (parse-statement tokens)] @@ -295,27 +303,37 @@ (= kind :left-curly) (parse-compound-statement tokens) :else (parse-expression-statement tokens))) +(defn parameter-node [token] + {:parameter-name (:literal token) + :identifier (:literal token) + :parameter-type (:kind token)}) + +(defn specifier-node [{:keys [kind] :as token}] + (let [specifier-type (condp = kind + :kw-int :int + :kw-static :static + :kw-extern :extern + (throw (ex-info "Parser Error. Invalid specifier." {:specifier-token token})))] + {:type :specifier + :specifier-type specifier-type})) + (defn variable-declaration-node - ([identifier] - {:type :declaration - :declaration-type :variable - :identifier identifier}) - ([identifier v] + ([identifier storage-class] + (variable-declaration-node identifier storage-class nil)) + ([identifier storage-class v] {:type :declaration + :storage-class storage-class :declaration-type :variable :identifier identifier :initial v})) (defn function-declaration-node - ([return-type identifier params] - {:type :declaration - :return-type return-type - :declaration-type :function - :identifier identifier - :parameters params}) - ([return-type identifier params body] + ([return-type storage-class identifier params] + (function-declaration-node return-type storage-class identifier params nil)) + ([return-type storage-class identifier params body] {:type :declaration :return-type return-type + :storage-class storage-class :declaration-type :function :identifier identifier :parameters params @@ -336,46 +354,58 @@ [ident-token tokens])) [rest-params tokens] (parse-repeatedly tokens parse-comma-f :right-paren) [_ tokens] (expect :right-paren tokens) - map-param-f (fn [p] - {:parameter-name (:literal p) - :identifier (:literal p) - :parameter-type (:kind p)}) - params (map map-param-f (into [ident-token] (vec rest-params)))] + params (map parameter-node (into [ident-token] (vec rest-params)))] [params tokens])))) -(defn- parse-function-declaration [tokens] - (let [[{ret-kind :kind} tokens] (expect :kw-int tokens) - [{fn-name :literal} tokens] (expect :identifier tokens) +(defn- parse-function-declaration [return-type storage-class tokens] + (let [[{fn-name :literal} tokens] (expect :identifier tokens) [_ tokens] (expect :left-paren tokens) [params tokens] (parse-param-list tokens) semicolon? (= :semicolon (:kind (first tokens)))] (if semicolon? (let [[_ tokens] (expect :semicolon tokens)] - [(function-declaration-node (keyword->type ret-kind) fn-name params) tokens]) + [(function-declaration-node return-type storage-class fn-name params) tokens]) (let [[body tokens] (parse-block tokens)] - [(function-declaration-node (keyword->type ret-kind) fn-name params body) tokens])))) + [(function-declaration-node return-type storage-class fn-name params body) tokens])))) -(defn- parse-variable-declaration [tokens] - (let [[_ tokens] (expect :kw-int tokens) - [ident-token tokens] (expect :identifier tokens) +(defn- parse-variable-declaration [_variable-type storage-class tokens] + (let [[ident-token tokens] (expect :identifier tokens) [{kind :kind} :as tokens] tokens] (cond (= kind :semicolon) (let [[_ tokens] (expect :semicolon tokens)] - [(variable-declaration-node (:literal ident-token)) tokens]) + [(variable-declaration-node (:literal ident-token) storage-class) tokens]) (= kind :assignment) (let [[_ tokens] (expect :assignment tokens) [exp-node tokens] (parse-exp tokens) [_ tokens] (expect :semicolon tokens)] - [(variable-declaration-node (:literal ident-token) exp-node) tokens]) + [(variable-declaration-node (:literal ident-token) storage-class exp-node) tokens]) :else (throw (ex-info "Parser error. Not able to parse variable declaration." {}))))) +(defn- parse-specifier [[{:keys [kind] :as token} & rst]] + (if-not (contains? #{:kw-int :kw-static :kw-extern} kind) + (exc/parser-error "Invalid token for specifier" {:token token}) + [(specifier-node token) rst])) + +(defn- parse-type-and-storage-class [specifiers] + (let [{types true, storage-classes false} (group-by #(= :int (:specifier-type %)) specifiers) + type-specifier (if (not= 1 (count types)) + (exc/parser-error "Invalid type specifier." {:types types}) + (:specifier-type (first types))) + storage-class (if (> (count storage-classes) 1) + (exc/parser-error "Invalid storage class." {:storage-classes storage-classes}) + (:specifier-type (first storage-classes)))] + {:type-specifier type-specifier + :storage-class storage-class})) + (defn- parse-declaration [tokens] - (let [fn? (= :left-paren (:kind (nth tokens 2)))] + (let [[specifiers tokens] (parse-repeatedly tokens parse-specifier :identifier) + {type-specifier :type-specifier, storage-class :storage-class} (parse-type-and-storage-class specifiers) + fn? (= :left-paren (:kind (nth tokens 1)))] (if fn? - (parse-function-declaration tokens) - (parse-variable-declaration tokens)))) + (parse-function-declaration type-specifier storage-class tokens) + (parse-variable-declaration type-specifier storage-class tokens)))) (defn- parse-block-item [[token :as tokens]] - (if (= :kw-int (:kind token)) + (if (contains? #{:kw-int :kw-static :kw-extern} (:kind token)) (parse-declaration tokens) (parse-statement tokens))) @@ -386,9 +416,9 @@ [block-items tokens])) (defn- parse-program [tokens] - (let [[fn-declaratrions tokens] (parse-repeatedly tokens parse-function-declaration :eof) + (let [[declarations tokens] (parse-repeatedly tokens parse-declaration :eof) _ (expect :eof tokens)] - fn-declaratrions)) + declarations)) (defn parse [tokens] (-> tokens @@ -402,4 +432,17 @@ (comment + (parse-from-src " +int main(void) { + + int x = 0; + + for (static int i = 0; i < 10; i = i + 1) { + x = x + 1; + } + + return x; +} +") + ()) |