fix a few linux compilation warnings

core/src/fxcodec/libjpeg/fpdfapi_jcmainct.c

 #if !defined(_FX_JPEG_TURBO_)
 /*
  * jcmainct.c
  *
  * Copyright (C) 1994-1996, Thomas G. Lane.
  * This file is part of the Independent JPEG Group's software.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains the main buffer controller for compression.
  * The main buffer lies between the pre-processor and the JPEG
@@ skipping 51 matching lines @@
 #endif
 
 
 /*
  * Initialize for a processing pass.
  */
 
 METHODDEF(void)
 start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
 {
-  my_main_ptr main = (my_main_ptr) cinfo->main;
+  my_main_ptr my_main = (my_main_ptr) cinfo->main;
 
   /* Do nothing in raw-data mode. */
   if (cinfo->raw_data_in)
     return;
 
-  main->cur_iMCU_row = 0;       /* initialize counters */
-  main->rowgroup_ctr = 0;
-  main->suspended = FALSE;
-  main->pass_mode = pass_mode;  /* save mode for use by process_data */
+  my_main->cur_iMCU_row = 0;    /* initialize counters */
+  my_main->rowgroup_ctr = 0;
+  my_main->suspended = FALSE;
+  my_main->pass_mode = pass_mode;       /* save mode for use by process_data */
 
   switch (pass_mode) {
   case JBUF_PASS_THRU:
 #ifdef FULL_MAIN_BUFFER_SUPPORTED
-    if (main->whole_image[0] != NULL)
+    if (my_main->whole_image[0] != NULL)
       ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
 #endif
-    main->pub.process_data = process_data_simple_main;
+    my_main->pub.process_data = process_data_simple_main;
     break;
 #ifdef FULL_MAIN_BUFFER_SUPPORTED
   case JBUF_SAVE_SOURCE:
   case JBUF_CRANK_DEST:
   case JBUF_SAVE_AND_PASS:
-    if (main->whole_image[0] == NULL)
+    if (my_main->whole_image[0] == NULL)
       ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
-    main->pub.process_data = process_data_buffer_main;
+    my_main->pub.process_data = process_data_buffer_main;
     break;
 #endif
   default:
     ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
     break;
   }
 }
 
 
 /*
  * Process some data.
  * This routine handles the simple pass-through mode,
  * where we have only a strip buffer.
  */
 
 METHODDEF(void)
 process_data_simple_main (j_compress_ptr cinfo,
                           JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
                           JDIMENSION in_rows_avail)
 {
-  my_main_ptr main = (my_main_ptr) cinfo->main;
+  my_main_ptr my_main = (my_main_ptr) cinfo->main;
 
-  while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
+  while (my_main->cur_iMCU_row < cinfo->total_iMCU_rows) {
     /* Read input data if we haven't filled the main buffer yet */
-    if (main->rowgroup_ctr < DCTSIZE)
+    if (my_main->rowgroup_ctr < DCTSIZE)
       (*cinfo->prep->pre_process_data) (cinfo,
                                         input_buf, in_row_ctr, in_rows_avail,
-                                        main->buffer, &main->rowgroup_ctr,
+                                        my_main->buffer, &my_main->rowgroup_ctr,
                                         (JDIMENSION) DCTSIZE);
 
     /* If we don't have a full iMCU row buffered, return to application for
      * more data.  Note that preprocessor will always pad to fill the iMCU row
      * at the bottom of the image.
      */
-    if (main->rowgroup_ctr != DCTSIZE)
+    if (my_main->rowgroup_ctr != DCTSIZE)
       return;
 
     /* Send the completed row to the compressor */
-    if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
+    if (! (*cinfo->coef->compress_data) (cinfo, my_main->buffer)) {
       /* If compressor did not consume the whole row, then we must need to
        * suspend processing and return to the application.  In this situation
        * we pretend we didn't yet consume the last input row; otherwise, if
        * it happened to be the last row of the image, the application would
        * think we were done.
        */
-      if (! main->suspended) {
+      if (! my_main->suspended) {
         (*in_row_ctr)--;
-        main->suspended = TRUE;
+        my_main->suspended = TRUE;
       }
       return;
     }
     /* We did finish the row.  Undo our little suspension hack if a previous
      * call suspended; then mark the main buffer empty.
      */
-    if (main->suspended) {
+    if (my_main->suspended) {
       (*in_row_ctr)++;
-      main->suspended = FALSE;
+      my_main->suspended = FALSE;
     }
-    main->rowgroup_ctr = 0;
-    main->cur_iMCU_row++;
+    my_main->rowgroup_ctr = 0;
+    my_main->cur_iMCU_row++;
   }
 }
 
 
 #ifdef FULL_MAIN_BUFFER_SUPPORTED
 
 /*
  * Process some data.
  * This routine handles all of the modes that use a full-size buffer.
  */
@@ skipping 70 matching lines @@
 #endif /* FULL_MAIN_BUFFER_SUPPORTED */
 
 
 /*
  * Initialize main buffer controller.
  */
 
 GLOBAL(void)
 jinit_c_main_controller (j_compress_ptr cinfo, boolean need_full_buffer)
 {
-  my_main_ptr main;
+  my_main_ptr my_main;
   int ci;
   jpeg_component_info *compptr;
 
-  main = (my_main_ptr)
+  my_main = (my_main_ptr)
     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
                                 SIZEOF(my_main_controller));
-  cinfo->main = (struct jpeg_c_main_controller *) main;
-  main->pub.start_pass = start_pass_main;
+  cinfo->main = (struct jpeg_c_main_controller *) my_main;
+  my_main->pub.start_pass = start_pass_main;
 
   /* We don't need to create a buffer in raw-data mode. */
   if (cinfo->raw_data_in)
     return;
 
   /* Create the buffer.  It holds downsampled data, so each component
    * may be of a different size.
    */
   if (need_full_buffer) {
 #ifdef FULL_MAIN_BUFFER_SUPPORTED
     /* Allocate a full-image virtual array for each component */
     /* Note we pad the bottom to a multiple of the iMCU height */
     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
          ci++, compptr++) {
-      main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
+      my_main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
         ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
          compptr->width_in_blocks * DCTSIZE,
          (JDIMENSION) jround_up((long) compptr->height_in_blocks,
                                 (long) compptr->v_samp_factor) * DCTSIZE,
          (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
     }
 #else
     ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
 #endif
   } else {
 #ifdef FULL_MAIN_BUFFER_SUPPORTED
-    main->whole_image[0] = NULL; /* flag for no virtual arrays */
+    my_main->whole_image[0] = NULL; /* flag for no virtual arrays */
 #endif
     /* Allocate a strip buffer for each component */
     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
          ci++, compptr++) {
-      main->buffer[ci] = (*cinfo->mem->alloc_sarray)
+      my_main->buffer[ci] = (*cinfo->mem->alloc_sarray)
         ((j_common_ptr) cinfo, JPOOL_IMAGE,
          compptr->width_in_blocks * DCTSIZE,
          (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
     }
   }
 }
 
 #endif //_FX_JPEG_TURBO_