mesa: Prepare for the MESA_FORMAT_* enum to be sparse.

To redefine MESA_FORMAT in terms of PIPE_FORMAT enums, we need to fix
places where we iterated up to MESA_FORMAT_COUNT.  I use
_mesa_get_format_name(f) == NULL as the signal that it's not an enum
value with a MESA_FORMAT.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/mesa/drivers/dri/i965/brw_surface_formats.c

@@ -217,6 +217,8 @@ intel_screen_init_surface_formats(struct intel_screen *screen)
       gen += 5;
 
    for (format = MESA_FORMAT_NONE + 1; format < MESA_FORMAT_COUNT; format++) {
+      if (!_mesa_get_format_name(format))
+         continue;
       enum isl_format texture, render;
       bool is_integer = _mesa_is_format_integer_color(format);
 

src/mesa/main/format_info.py

@@ -182,7 +182,7 @@ bf_map = {
 }
 
 for fmat in formats:
-   print('   {')
+   print('   [{0}] = {{'.format(fmat.name))
    print('      .Name = {0},'.format(fmat.name))
    print('      .StrName = "{0}",'.format(fmat.name))
    print('      .Layout = {0},'.format('MESA_FORMAT_LAYOUT_' + fmat.layout.upper()))

src/mesa/main/formats.c

@@ -85,6 +85,13 @@ _mesa_get_format_info(mesa_format format)
 {
    const struct mesa_format_info *info = &format_info[format];
    STATIC_ASSERT(ARRAY_SIZE(format_info) == MESA_FORMAT_COUNT);
+
+   /* The MESA_FORMAT_* enums are sparse, don't return a format info
+    * for empty entries.
+    */
+   if (info->Name == MESA_FORMAT_NONE && format != MESA_FORMAT_NONE)
+      return NULL;
+
    assert(info->Name == format);
    return info;
 }
@@ -95,6 +102,8 @@ const char *
 _mesa_get_format_name(mesa_format format)
 {
    const struct mesa_format_info *info = _mesa_get_format_info(format);
+   if (!info)
+      return NULL;
    return info->StrName;
 }
 
@@ -465,7 +474,7 @@ format_array_format_table_init(void)
 
    for (f = 1; f < MESA_FORMAT_COUNT; ++f) {
       info = _mesa_get_format_info(f);
-      if (!info->ArrayFormat)
+      if (!info || !info->ArrayFormat)
          continue;
 
 #if UTIL_ARCH_LITTLE_ENDIAN
@@ -1409,15 +1418,17 @@ _mesa_uncompressed_format_to_type_and_comps(mesa_format format,
    case MESA_FORMAT_COUNT:
       assert(0);
       return;
-   default:
+   default: {
+      const char *name = _mesa_get_format_name(format);
       /* Warn if any formats are not handled */
       _mesa_problem(NULL, "bad format %s in _mesa_uncompressed_format_to_type_and_comps",
-                    _mesa_get_format_name(format));
+                    name ? name : "???");
       assert(format == MESA_FORMAT_NONE ||
              _mesa_is_format_compressed(format));
       *datatype = 0;
       *comps = 1;
    }
+   }
 }
 
 /**

src/mesa/main/tests/mesa_formats.cpp

@@ -45,6 +45,9 @@ TEST(MesaFormatsTest, FormatTypeAndComps)
       mesa_format f = (mesa_format) fi;
       SCOPED_TRACE(_mesa_get_format_name(f));
 
+      if (!_mesa_get_format_name(f))
+         continue;
+
       /* This function will emit a problem/warning if the format is
        * not handled.
        */
@@ -68,6 +71,9 @@ TEST(MesaFormatsTest, FormatSanity)
    for (int fi = 0; fi < MESA_FORMAT_COUNT; ++fi) {
       mesa_format f = (mesa_format) fi;
       SCOPED_TRACE(_mesa_get_format_name(f));
+      if (!_mesa_get_format_name(f))
+         continue;
+
       GLenum datatype = _mesa_get_format_datatype(f);
       GLint r = _mesa_get_format_bits(f, GL_RED_BITS);
       GLint g = _mesa_get_format_bits(f, GL_GREEN_BITS);

src/mesa/state_tracker/st_format.c

@@ -2435,6 +2435,9 @@ st_choose_matching_format(struct st_context *st, unsigned bind,
    mesa_format mesa_format;
 
    for (mesa_format = 1; mesa_format < MESA_FORMAT_COUNT; mesa_format++) {
+      if (!_mesa_get_format_name(mesa_format))
+         continue;
+
       if (_mesa_is_format_srgb(mesa_format)) {
          continue;
       }

src/mesa/state_tracker/tests/st_format.c

@@ -66,6 +66,9 @@ int main(int argc, char **argv)
 
    /* test all Mesa formats */
    for (i = 1; i < MESA_FORMAT_COUNT; i++) {
+      if (!_mesa_get_format_name(i))
+         continue;
+
       enum pipe_format pf;
 
       assert(!st_compressed_format_fallback(st, i));