Ticket #12662: 0001-Declare-certain-variables-as-volaile-to-silence-long.patch

build/jam/ArchitectureRules

@@ -612 +612 @@
     EnableWerror src add-ons translators jpeg ; # gcc2
     EnableWerror src add-ons translators jpeg2000 ;
     EnableWerror src add-ons translators pcx ;
-#   EnableWerror src add-ons translators png ; # gcc2
+    EnableWerror src add-ons translators png ; # gcc2
     EnableWerror src add-ons translators ppm ;
     EnableWerror src add-ons translators raw ;
     EnableWerror src add-ons translators rtf ;

src/add-ons/translators/png/PNGTranslator.cpp

@@ -193 +193 @@
 // Returns:
 // ---------------------------------------------------------------
 PNGTranslator::PNGTranslator()
-    : BaseTranslator(B_TRANSLATE("PNG images"), 
+    : BaseTranslator(B_TRANSLATE("PNG images"),
         B_TRANSLATE("PNG image translator"),
         PNG_TRANSLATOR_VERSION,
         sInputFormats, kNumInputFormats,
@@ -299 +299 @@
     if (identify_png_header(inSource, NULL) != B_OK)
         return B_NO_TRANSLATOR;
 
-    status_t result = B_ERROR;
+    volatile status_t result = B_ERROR;
         // if a libpng errors before this is set
         // to a different value, the above is what
         // will be returned from this function
@@ -307 +307 @@
     bool bheaderonly = false, bdataonly = false;
 
     // for storing decoded PNG row data
-    uint8 **prows = NULL, *prow = NULL;
-    png_uint_32 nalloc = 0;
+    uint8 ** volatile prows = NULL, * volatile prow = NULL;
+    volatile png_uint_32 nalloc = 0;
 
     png_structp ppng = NULL;
     png_infop pinfo = NULL;
@@ -424 +424 @@
                 break;
             }
             for (png_uint_32 i = 0; i < height; i++) {
-                png_read_row(ppng, prow, NULL);
-                outDestination->Write(prow, width * kbytes);
+                // prow was declared volatile to silence warning about
+                // being clobbered by longjmp
+                png_read_row(ppng, const_cast<uint8*>(prow), NULL);
+                outDestination->Write(const_cast<uint8*>(prow),
+                                        width * kbytes);
             }
             result = B_OK;
                 // Set OK status here, because, in the event of
@@ -440 +443 @@
 
         } else {
             // interlaced PNG image
-            prows = new uint8 *[height];
+            // prows = new uint8 *[height];
+            prows = static_cast<uint8 ** volatile>(new uint8 *[height]);
             if (!prows) {
                 result = B_NO_MEMORY;
                 break;
@@ -455 +459 @@
             if (nalloc < height)
                 result = B_NO_MEMORY;
             else {
-                png_read_image(ppng, prows);
+                png_read_image(ppng, const_cast<uint8**>(prows));
 
                 for (png_uint_32 i = 0; i < height; i++)
-                    outDestination->Write(prows[i], width * kbytes);
+                    outDestination->Write(const_cast<uint8*>(prows[i]),
+                                            width * kbytes);
                 result = B_OK;
                     // Set OK status here, because, in the event of
                     // an error, png_read_end() will longjmp to error
@@ -717 +722 @@
     if (result != B_OK)
         return result;
 
-    const color_map *pmap = NULL;
+    const color_map * volatile pmap = NULL;
     if (bitsHeader.colors == B_CMAP8) {
         pmap = system_colors();
         if (!pmap)
@@ -728 +733 @@
     width = static_cast<png_uint_32>(bitsHeader.bounds.Width() + 1);
     height = static_cast<png_uint_32>(bitsHeader.bounds.Height() + 1);
 
-    int32 pngBytesPerPixel = 0;
-    int bit_depth, color_type, interlace_type;
+    volatile int32 pngBytesPerPixel = 0;
+    int bit_depth, interlace_type;
+    volatile int color_type;
     bit_depth = 8;
     switch (bitsHeader.colors) {
         case B_RGBA32:
@@ -768 +774 @@
     }
     interlace_type = fSettings->SetGetInt32(PNG_SETTING_INTERLACE);
 
-    int32 bitsBytesPerPixel = 0;
+    volatile int32 bitsBytesPerPixel = 0;
     switch (bitsHeader.colors) {
         case B_RGBA32:
         case B_RGBA32_BIG:
@@ -804 +810 @@
             return B_NO_TRANSLATOR;
     };
 
-    uint8 *pbitsrow = NULL, *prow = NULL;
+    uint8 * volatile pbitsrow = NULL, * volatile prow = NULL;
         // row buffers
     // image buffer for writing whole png image at once
-    uint8 **prows = NULL;
-    png_uint_32 nalloc = 0;
+    uint8 ** volatile prows = NULL;
+    volatile png_uint_32 nalloc = 0;
 
     png_structp ppng = NULL;
     png_infop pinfo = NULL;
@@ -886 +892 @@
             for (png_uint_32 i = 0; i < height; i++) {
                 inSource->Read(pbitsrow, bitsHeader.rowBytes);
 
+                // We're casting away pmap's virtualness, not its constness
                 pix_bits_to_png(pbitsrow, prow, bitsHeader.colors, width,
-                    pmap, bitsBytesPerPixel);
+                    const_cast<color_map*>(pmap), bitsBytesPerPixel);
 
                 png_write_row(ppng, prow);
             }
@@ -985 +992 @@
 PNGTranslator::NewConfigView(TranslatorSettings *settings)
 {
     return new PNGView(BRect(0, 0, PNG_VIEW_WIDTH, PNG_VIEW_HEIGHT),
-        B_TRANSLATE("PNGTranslator Settings"), B_FOLLOW_ALL, 
+        B_TRANSLATE("PNGTranslator Settings"), B_FOLLOW_ALL,
         B_WILL_DRAW, settings);
 }