From 5148ded7268b569fd5e720f90b44645c83ac3e9e Mon Sep 17 00:00:00 2001
From: Ben Fuhrmannek
Date: Mon, 16 Aug 2021 15:47:01 +0200
Subject: fincy new scanner/parser for config rules + fixed a few bugs along
 the way + fixed related unittests

---
 src/sp_config_scanner.re | 139 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 src/sp_config_scanner.re

(limited to 'src/sp_config_scanner.re')

diff --git a/src/sp_config_scanner.re b/src/sp_config_scanner.re
new file mode 100644
index 0000000..075c343
--- /dev/null
+++ b/src/sp_config_scanner.re
@@ -0,0 +1,139 @@
+#include "php_snuffleupagus.h"
+
+/*!types:re2c*/
+
+#define cs_error_log(fmt, ...) sp_log_err("config", fmt, ##__VA_ARGS__)
+
+zend_string *sp_get_arg_string(sp_parsed_keyword *kw) {
+  if (!kw || !kw->arg) {
+    return NULL;
+  }
+  zend_string *ret = zend_string_init(kw->arg, kw->arglen, 1);
+  char *pin, *pout;
+  pin = pout = ZSTR_VAL(ret);
+  char *pend = pin + ZSTR_LEN(ret);
+
+  while (pin < pend) {
+    if (*pin == '\\') {
+      pin++;
+    }
+    *pout = *pin;
+    pin++; pout++;
+  }
+
+  if (pin != pout) {
+    size_t len = pout - ZSTR_VAL(ret);
+    ret = zend_string_truncate(ret, len, 1);
+    ZSTR_VAL(ret)[len] = 0;
+  }
+
+  return ret;
+}
+
+zend_string *sp_get_textual_representation(sp_parsed_keyword *parsed_rule) {
+  // a rule is "sp.keyword...keyword(arg);\0"
+  size_t len = 3; // sp + ;
+  sp_parsed_keyword *kw;
+  for (kw = parsed_rule; kw->kw; kw++) {
+    len++; // .
+    len += kw->kwlen;
+    if (kw->argtype == SP_ARGTYPE_EMPTY) {
+      len += 2; // ()
+    } else if (kw->argtype == SP_ARGTYPE_STR) {
+        len += 4;
+        len += kw->arglen;
+    }
+  }
+  zend_string *ret = zend_string_alloc(len, 1);
+  char *ptr = ZSTR_VAL(ret);
+  memcpy(ptr, "sp", 2); ptr += 2;
+  for (kw = parsed_rule; kw->kw; kw++) {
+    *ptr++ = '.';
+    memcpy(ptr, kw->kw, kw->kwlen); ptr += kw->kwlen;
+    if (kw->argtype == SP_ARGTYPE_EMPTY || kw->argtype == SP_ARGTYPE_STR || kw->argtype == SP_ARGTYPE_UNKNOWN) {
+      *ptr++ = '(';
+    }
+    if (kw->argtype == SP_ARGTYPE_STR && kw->arg) {
+      *ptr++ = '"';
+      memcpy(ptr, kw->arg, kw->arglen); ptr += kw->arglen;
+      *ptr++ = '"';
+    }
+    if (kw->argtype == SP_ARGTYPE_EMPTY || kw->argtype == SP_ARGTYPE_STR || kw->argtype == SP_ARGTYPE_UNKNOWN) {
+      *ptr++ = ')';
+    }
+  }
+  *ptr++ = ';';
+  *ptr = 0;
+  return ret;
+}
+
+zend_result sp_config_scan(char *data, zend_result (*process_rule)(sp_parsed_keyword*))
+{
+  const char *YYCURSOR = data;
+  const char *YYMARKER, *t1, *t2, *t3, *t4;
+  /*!stags:re2c format = 'const char *@@;\n'; */
+
+  const int max_keywords = 16;
+  sp_parsed_keyword parsed_rule[max_keywords+1];
+  int kw_i = 0;
+
+  int cond = yycinit;
+  long lineno = 1;
+
+  /*!re2c
+    re2c:define:YYCTYPE = char;
+    // re2c:define:YYCURSOR = data;
+    re2c:yyfill:enable = 0;
+    re2c:flags:tags = 1;
+    re2c:api:style = free-form;
+    re2c:define:YYGETCONDITION = "cond";
+    re2c:define:YYSETCONDITION = "cond = @@;";
+
+    end = "\x00";
+    nl = "\r"?"\n";
+    ws = [ \t];
+    keyword = [a-zA-Z_][a-zA-Z0-9_]*;
+    string = "\"" ("\\\"" | [^"\r\n])* "\"";
+
+    <init> *       { cs_error_log("Parser error on line %d", lineno); return FAILURE; }
+    <init> ws+     { goto yyc_init; }
+    <init> [;#] .* { goto yyc_init; }
+    <init> nl      { lineno++; goto yyc_init; }
+    <init> "sp"    { kw_i = 0;  goto yyc_rule; }
+    <init> end     { return SUCCESS; }
+
+    <rule> ws+     {  goto yyc_rule; }
+    <rule> nl / ( nl | ws )* "." {  lineno++; goto yyc_rule; }
+    <rule> "." @t1 keyword @t2 ( "(" @t3 string? @t4 ")" )?  {
+      if (kw_i == max_keywords) {
+        cs_error_log("Too many keywords in rule (more than %d) on line %d", max_keywords, lineno);
+        return FAILURE;
+      }
+      sp_parsed_keyword kw = {.kw = (char*)t1, .kwlen = t2-t1, .arg = (char*)t3, .arglen = t4-t3, .argtype = SP_ARGTYPE_UNKNOWN, .lineno = lineno};
+      if (t3 && t4) {
+        if (t3 == t4) {
+          kw.argtype = SP_ARGTYPE_EMPTY;
+        } else if (t4-t2 >= 2) {
+          kw.arg = (char*)t3 + 1;
+          kw.arglen = t4 - t3 - 2;
+          kw.argtype = SP_ARGTYPE_STR;
+        }
+      } else {
+        kw.argtype = SP_ARGTYPE_NONE;
+      }
+      parsed_rule[kw_i++] = kw;
+      goto yyc_rule;
+    }
+    <rule> ";"     {
+      end_of_rule:
+      parsed_rule[kw_i++] = (sp_parsed_keyword){0, 0, 0, 0, 0, 0};
+      if (process_rule && process_rule(parsed_rule) != SUCCESS) {
+        return FAILURE;
+      }
+      goto yyc_init;
+    }
+    <rule> *       { goto end_of_rule; }
+
+  */
+  return FAILURE;
+}
\ No newline at end of file
-- 
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