pa1.2: use flex and bason to implement expr parser

nemu/src/isa/riscv64

@@ -0,0 +1 @@
+riscv32

nemu/src/monitor/sdb/.gitignore

@@ -0,0 +1,2 @@
+addrexp_lex.h
+addrexp.h

nemu/src/monitor/sdb/addrexp.l

@@ -0,0 +1,13 @@
+%{
+    #include <addrexp.h>
+%}
+%option noyywrap
+
+%%
+
+0[xX][0-9a-fA-F]+ { yylval = strtol(yytext, NULL, 16); return HEX_NUMBER; }
+[0-9]+            { yylval = atoi(yytext); return NUMBER; }
+[+\-*/()]         { return *yytext; }
+[ \t]             {  }
+.                 { printf("Unexpected character: %s\n", yytext); }
+%%

nemu/src/monitor/sdb/addrexp.y

@@ -0,0 +1,36 @@
+%{
+    #include <stdio.h>
+    #include <stdlib.h>
+    #include <stdint.h>
+    extern int yylex(void);
+    void yyerror(uint32_t *result, const char *s) {
+        fprintf(stderr, "Error: %s\n", s);
+    }
+%}
+
+%token NUMBER HEX_NUMBER
+%start input
+%define api.value.type { uint32_t }
+%parse-param { uint32_t *result }
+%left '+' '-'
+%left '*' '/'
+
+%%
+input
+    : expression { *result = $1; }
+    ;
+
+expression
+    : expression '+' expression { $$ = $1 + $3; }
+    | expression '-' expression { $$ = $1 - $3; }
+    | expression '*' expression { $$ = $1 * $3; } 
+    | expression '/' expression { $$ = $1 / $3; }
+    | '-' number { $$ = -$2; }
+    | '(' expression ')' { $$ = $2; }
+    | number { $$ = $1; }
+
+number
+    : NUMBER 
+    | HEX_NUMBER 
+
+%%

nemu/src/monitor/sdb/expr.c

@@ -21,24 +21,18 @@
 #include <regex.h>
 
 enum {
-  TK_NOTYPE = 256, TK_EQ,
-
-  /* TODO: Add more token types */
-
+  TK_NOTYPE = 256, TK_EQ, TK_NUMBER,
+  LEX_GROUP_OPERATOR, LEX_GROUP_DIGIT
 };
 
 static struct rule {
   const char *regex;
   int token_type;
 } rules[] = {
-
-  /* TODO: Add more rules.
-   * Pay attention to the precedence level of different rules.
-   */
-
-  {" +", TK_NOTYPE},    // spaces
-  {"\\+", '+'},         // plus
-  {"==", TK_EQ},        // equal
+  {"[ \t]+", TK_NOTYPE},
+  {"==", TK_EQ},
+  {"[0-9]+", LEX_GROUP_DIGIT},
+  {"[\\+-*/()", LEX_GROUP_OPERATOR},
 };
 
 #define NR_REGEX ARRLEN(rules)
@@ -95,6 +89,16 @@ static bool make_token(char *e) {
          */
 
         switch (rules[i].token_type) {
+          case LEX_GROUP_OPERATOR:
+            tokens[nr_token].type = *substr_start;
+            tokens[nr_token].str[0] = '\0';
+            nr_token++;
+            break;
+          case LEX_GROUP_DIGIT:
+            tokens[nr_token].type = TK_NUMBER;
+            nr_token++;
+            break;
+          case TK_NOTYPE: break;
           default: TODO();
         }
 

nemu/src/monitor/sdb/filelist.mk

@@ -0,0 +1,3 @@
+SRCS-y += src/monitor/sdb/addrexp.tag.c src/monitor/sdb/addrexp.yy.c
+INC_PATH += src/monitor/sdb
+LFLAGS += -DYY_NO_UNPUT -DYY_NO_INPUT

nemu/src/monitor/sdb/sdb.c

@@ -23,6 +23,8 @@
 #include <readline/history.h>
 #include <readline/readline.h>
 #include <stdint.h>
+#include <addrexp.h>
+#include <addrexp_lex.h>
 
 static int is_batch_mode = false;
 
@@ -107,7 +109,7 @@ static word_t parse_uint(const char *arg, bool *success) {
   char *endptr;
   uintmax_t n = strtoumax(arg, &endptr, base);
   if (errno == ERANGE || n > WORD_T_MAX) {
-    printf("%s is exceed the limit of uint\n", arg);
+    printf("%s exceed the limit of uint\n", arg);
     *success = false;
     return 0;
   } else if (arg == endptr) {
@@ -129,10 +131,14 @@ static paddr_t parse_expr(const char *arg, bool *success) {
     *success = false;
     return 0;
   } else {
-    bool res = false;
+    // bool res = false;
     // FIXME: We cannot use `parse_uint` here, it accept `-1234` as input
-    paddr_t addr = parse_uint(arg, &res);
-    *success = res;
+    // paddr_t addr = parse_uint(arg, &res);
+    // *success = res;
+    paddr_t addr;
+    yy_scan_string(arg);
+    *success = !yyparse(&addr);
+    yylex_destroy();
     return addr;
   }
 }
@@ -199,7 +205,7 @@ static int cmd_x(char *args) {
   return 0;
 
 wrong_usage:
-  printf("Invalid argument for command si: %s\n", args);
+  printf("Invalid argument for command x: %s\n", args);
   printf("Usage: x [N: uint] [EXPR: <expr>]\n");
   return 0;
 }
@@ -324,8 +330,8 @@ void sdb_mainloop() {
 }
 
 void init_sdb() {
-  /* Compile the regular expressions. */
-  init_regex();
+  // /* Compile the regular expressions. */
+  // init_regex();
 
   /* Initialize the watchpoint pool. */
   init_wp_pool();