[Mesa-dev] [PATCH 3/4] mesa/main: fix gl_buffer_index enum comparison

[Rob Herring]

For clang, enums are unsigned by default and gives the following warning:

external/mesa3d/src/mesa/main/buffers.c:764:21: warning: comparison of constant -1 with expression of type 'gl_buffer_index' is always false [-Wtautological-constant-out-of-range-compare]
      if (srcBuffer == -1) {
          ~~~~~~~~~ ^  ~~

Replace -1 with an enum value to fix this.

Signed-off-by: Rob Herring <robh at kernel.org>
---
 src/mesa/main/buffers.c | 6 +++---
 src/mesa/main/mtypes.h  | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
index 7d17ae92de23..c5846e85c21d 100644
--- a/src/mesa/main/buffers.c
+++ b/src/mesa/main/buffers.c
@@ -752,16 +752,16 @@ read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
 
    if (buffer == GL_NONE) {
       /* This is legal--it means that no buffer should be bound for reading. */
-      srcBuffer = -1;
+      srcBuffer = BUFFER_NONE;
    }
    else {
       /* general case / window-system framebuffer */
       if (_mesa_is_gles3(ctx) && !is_legal_es3_readbuffer_enum(buffer))
-         srcBuffer = -1;
+         srcBuffer = BUFFER_NONE;
       else
          srcBuffer = read_buffer_enum_to_index(ctx, buffer);
 
-      if (srcBuffer == -1) {
+      if (srcBuffer == BUFFER_NONE) {
          _mesa_error(ctx, GL_INVALID_ENUM,
                      "%s(invalid buffer %s)", caller,
                      _mesa_enum_to_string(buffer));
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 29e4c67846a5..6b6937473054 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -144,7 +144,8 @@ typedef enum
    BUFFER_COLOR5,
    BUFFER_COLOR6,
    BUFFER_COLOR7,
-   BUFFER_COUNT
+   BUFFER_COUNT,
+   BUFFER_NONE = -1,
 } gl_buffer_index;
 
 /**
-- 
2.11.0