[Mesa-dev] [PATCH v2 18/18] mesa: Remove gl_extensions::dummy

[Nanley Chery]

From: Nanley Chery <nanley.g.chery at intel.com>

This variable existed to enable 0 as a valid error value for
name_to_offset(). Since o(extension_sentinel) is also a valid
error value, save space and replace this mysterious variable
with a less mysterious one (extension_sentinel).

v2. Reword git comment and update function comment (Emil)

Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>
---
 src/mesa/main/extensions.c | 11 ++++++-----
 src/mesa/main/mtypes.h     |  3 +--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index 3814633..b81bcc5 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -72,7 +72,7 @@ const struct mesa_extension _mesa_extension_table[] = {
 /**
  * Given an extension name, lookup up the corresponding member of struct
  * gl_extensions and return that member's offset (in bytes).  If the name is
- * not found in the \c _mesa_extension_table, return 0.
+ * not found in the \c _mesa_extension_table, return o(extension_sentinel).
  *
  * \param name Name of extension.
  * \return Offset of member in struct gl_extensions.
@@ -81,16 +81,17 @@ static size_t
 name_to_offset(const char* name)
 {
    unsigned i;
+   const size_t error_value = o(extension_sentinel);
 
    if (name == 0)
-      return 0;
+      return error_value;
 
    for (i = 0; i < ARRAY_SIZE(_mesa_extension_table); ++i) {
       if (strcmp(name, _mesa_extension_table[i].name) == 0)
 	 return _mesa_extension_table[i].offset;
    }
 
-   return 0;
+   return error_value;
 }
 
 /**
@@ -211,7 +212,7 @@ set_extension(struct gl_extensions *ext, const char *name, GLboolean state)
    size_t offset;
 
    offset = name_to_offset(name);
-   if (offset != 0 && (offset != o(dummy_true) || state != GL_FALSE)) {
+   if (offset != o(extension_sentinel) && (offset != o(dummy_true) || state != GL_FALSE)) {
       ((GLboolean *) ext)[offset] = state;
    }
 
@@ -323,7 +324,7 @@ _mesa_one_time_init_extension_overrides(void)
       }
 
       offset = set_extension(&_mesa_extension_override_enables, ext, enable);
-      if (offset != 0 && (offset != o(dummy_true) || enable != GL_FALSE)) {
+      if (offset != o(extension_sentinel) && (offset != o(dummy_true) || enable != GL_FALSE)) {
          ((GLboolean *) &_mesa_extension_override_disables)[offset] = !enable;
          recognized = true;
       } else {
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 3a7759c..bfb85af 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3630,9 +3630,8 @@ struct gl_constants
  */
 struct gl_extensions
 {
-   GLboolean dummy;  /* don't remove this! */
    GLboolean dummy_true;  /* Set true by _mesa_init_extensions(). */
-   GLboolean dummy_false; /* Set false by _mesa_init_extensions(). */
+   GLboolean dummy_false; /* Set false by zeroed initialization. */
    GLboolean ANGLE_texture_compression_dxt;
    GLboolean ARB_ES2_compatibility;
    GLboolean ARB_ES3_compatibility;
-- 
2.6.2