Fix for Ecc failing on empty files

Sources/Ecc/Main.cpp

@@ -1,4 +1,4 @@
-/* Copyright (c) 2002-2012 Croteam Ltd. 
+/* Copyright (c) 2002-2012 Croteam Ltd.
 This program is free software; you can redistribute it and/or modify
 it under the terms of version 2 of the GNU General Public License as published by
 the Free Software Foundation
@@ -63,7 +63,7 @@ char *LineDirective(int i)
   return strdup(str);
 }
 
-SType SType::operator+(const SType &other) 
+SType SType::operator+(const SType &other)
 {
   SType sum;
   sum.strString = stradd(strString, other.strString);
@@ -116,7 +116,7 @@ FILE *FOpen(const char *strFileName, char *strMode)
 /*
  * Print a header to an output file.
  */
-static void PrintHeader(FILE *f) 
+static void PrintHeader(FILE *f)
 {
   fprintf(f, "/*\n");
   fprintf(f, " * This file is generated by Entity Class Compiler, (c) CroTeam 1997-98\n");
@@ -174,13 +174,13 @@ void ReplaceFileRL(const char *strOld, const char *strNew)
     {
       continue;
     }
-    
+
     // process each charachter
     for(int ich=0;ich<ctch;ich++)
     {
       char *pchOld = &strOldBuff[iOldch];
       char *pchNew = &strNewBuff[ich];
-      
+
       if((*pchNew == '{') || (*pchNew == '}') || *pchNew == ';')
       {
         if((!bComment) && (!bQuotes) && (*(pchNew+1) != 13))
@@ -193,7 +193,7 @@ void ReplaceFileRL(const char *strOld, const char *strNew)
       }
       if(*pchNew == '"')
       {
-        // if this is quote 
+        // if this is quote
         if((ich>0) && (*(pchNew-1)=='\\')) { }
         else bQuotes = !bQuotes;
       }
@@ -227,8 +227,106 @@ void ReplaceFile(const char *strOld, const char *strNew)
   remove(strOld);
   rename(strNew, strOld);
 }
+
+enum ESStatus
+{
+    /* Appears to be non-empty, ready to parse. */
+    Good,
+    /* Appears to be empty, ignore it. */
+    Empty,
+    /* Error occured during status check. */
+    Error,
+};
+
+/* Determine whether or not our target ES file is indeed valid input. */
+ESStatus GetESStatus(char *filename)
+{
+    ESStatus result = ESStatus::Good;
+
+    // Read a temporary buffer of the entire file contents
+    fseek(_fInput, 0, SEEK_END);
+    size_t length = ftell(_fInput);
+    char* temporaryBuffer = (char*)malloc(length);
+    fseek(_fInput, 0, SEEK_SET);
+    fread(temporaryBuffer, length, 1, _fInput);
+    fclose(_fInput);
+
+    // First, let's remove line comments
+    char *commentBegin = NULL;
+    while (commentBegin = strstr(temporaryBuffer, "//"))
+    {
+        size_t commentLength = length;
+
+        char* lineEnding = strstr(commentBegin, "\n");
+        if (lineEnding)
+            commentLength = (size_t)(lineEnding) - (size_t)commentBegin;
+
+        memset(commentBegin, 0x20, commentLength);
+    }
+
+    // Then block comments
+    commentBegin = NULL;
+    while (commentBegin = strstr(temporaryBuffer, "/*"))
+    {
+        size_t commentLength = length;
+
+        char* commentEnd = strstr(commentBegin, "*/");
+        if (commentEnd)
+            commentLength = (size_t)(commentEnd + 3) - (size_t)commentBegin;
+        else
+        {
+            result = ESStatus::Error;
+            break;
+        }
+
+        memset(commentBegin, 0x20, commentLength);
+    }
+
+    // If we return here, it was because of unbalanced block comments
+    if (result != ESStatus::Good)
+    {
+        free(temporaryBuffer);
+        return result;
+    }
+
+    // Now we just loop through the buffer until we find something that's not 0x20 or \n
+    result = ESStatus::Empty;
+    for (size_t iteration = 0; iteration < length; iteration++)
+        if (temporaryBuffer[iteration] != 0x20 && temporaryBuffer[iteration] != '\n')
+        {
+            size_t checkLength = length;
+            char* checkStart = &temporaryBuffer[iteration];
+
+            char* lineEnding = strstr(checkStart, "\n");
+            if (lineEnding)
+                checkLength = (size_t)(lineEnding) - (size_t)checkStart;
+
+            // Loop through and use isdigit to check all the digits
+            checkStart[checkLength + 1] = 0x00;
+
+            for (int digit = 0; digit < strlen(checkStart); digit++)
+                if (checkStart[digit] != 0x20 && checkStart[digit] != '\n' && isdigit(checkStart[digit]))
+                    result = ESStatus::Good;
+                else if (checkStart[digit] != 0x20 && checkStart[digit] != '\n')
+                {
+                    // If this occurs, then the first non-whitespace line we read wasn't a number.
+                    result = ESStatus::Error;
+                    break;
+                }
+
+            break;
+        }
+
+
+    free(temporaryBuffer);
+    if (result == ESStatus::Good)
+        _fInput = FOpen(filename, "r");
+
+    return result;
+}
+
 /* Replace a file with a new file if they are different.
- * Used to keep .h files from constantly changing when you change the implementation. 
+ * Used to keep .h files from constantly changing when you change the implementation.
  */
 void ReplaceIfChanged(const char *strOld, const char *strNew)
 {
@@ -240,7 +338,7 @@ void ReplaceIfChanged(const char *strOld, const char *strNew)
     while (!feof(fOld)) {
       char strOldLine[4096] = "#l";
       char strNewLine[4096] = "#l";
-  
+
       // skip #line directives
       while(strNewLine[0]=='#' && strNewLine[1]=='l' && !feof(fNew)) {
         fgets(strNewLine, sizeof(strNewLine)-1, fNew);
@@ -283,6 +381,18 @@ int main(int argc, char *argv[])
   }
   // open the input file
   _fInput = FOpen(argv[1], "r");
+
+  // Make sure we're loading a valid ES file
+  ESStatus status = GetESStatus(argv[1]);
+
+  switch (status)
+  {
+      case ESStatus::Empty:
+          return EXIT_SUCCESS;
+      case ESStatus::Error:
+          return EXIT_FAILURE;
+  }
+
   //printf("%s\n", argv[1]);
   // open all the output files
   char *strImplementation    = ChangeFileNameExtension(argv[1], ".cpp_tmp");
@@ -333,7 +443,7 @@ int main(int argc, char *argv[])
     ReplaceFile(strImplementationOld, strImplementation);
     ReplaceIfChanged(strDeclarationOld, strDeclaration);
     ReplaceIfChanged(strTablesOld, strTables);
- 
+
     return EXIT_SUCCESS;
   // if there were errors
   } else {

Sources/Ecc/StdH.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2002-2012 Croteam Ltd. 
+/* Copyright (c) 2002-2012 Croteam Ltd.
 This program is free software; you can redistribute it and/or modify
 it under the terms of version 2 of the GNU General Public License as published by
 the Free Software Foundation
@@ -13,6 +13,7 @@ You should have received a copy of the GNU General Public License along
 with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
 
+#include <ctype.h>
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -27,4 +28,3 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <unistd.h>
 #define _fullpath(x, y, z) realpath(y, x)
 #endif
-