dri: Add KHR_no_error DRI extension

This basic extension allows usage of the __DRI_CTX_FLAG_NO_ERROR flag.
This includes support code for classic Mesa drivers to switch on the
no-error mode if the flag is set.

v2: Move to common DRI code.

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

include/GL/internal/dri_interface.h

@@ -1049,6 +1049,12 @@ struct __DRIdri2LoaderExtensionRec {
  */
 #define __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS	0x00000004
 
+/**
+ * \requires __DRI2_NO_ERROR.
+ *
+ */
+#define __DRI_CTX_FLAG_NO_ERROR			0x00000008
+
 /**
  * \name Context reset strategies.
  */
@@ -1611,6 +1617,19 @@ struct __DRIrobustnessExtensionRec {
    __DRIextension base;
 };
 
+/**
+ * No-error context driver extension.
+ *
+ * Existence of this extension means the driver can accept the
+ * __DRI_CTX_FLAG_NO_ERROR flag.
+ */
+#define __DRI2_NO_ERROR "DRI_NoError"
+#define __DRI2_NO_ERROR_VERSION 1
+
+typedef struct __DRInoErrorExtensionRec {
+   __DRIextension base;
+} __DRInoErrorExtension;
+
 /**
  * DRI config options extension.
  *

src/gallium/state_trackers/dri/dri2.c

@@ -1995,6 +1995,7 @@ static const __DRIextension *dri_screen_extensions[] = {
    &dri2ThrottleExtension.base,
    &dri2FenceExtension.base,
    &dri2InteropExtension.base,
+   &dri2NoErrorExtension.base,
    NULL
 };
 
@@ -2008,6 +2009,7 @@ static const __DRIextension *dri_robust_screen_extensions[] = {
    &dri2FenceExtension.base,
    &dri2InteropExtension.base,
    &dri2Robustness.base,
+   &dri2NoErrorExtension.base,
    NULL
 };
 

src/gallium/state_trackers/dri/dri_context.c

@@ -57,7 +57,8 @@ dri_create_context(gl_api api, const struct gl_config * visual,
    struct st_context_attribs attribs;
    enum st_context_error ctx_err = 0;
    unsigned allowed_flags = __DRI_CTX_FLAG_DEBUG |
-                            __DRI_CTX_FLAG_FORWARD_COMPATIBLE;
+                            __DRI_CTX_FLAG_FORWARD_COMPATIBLE |
+                            __DRI_CTX_FLAG_NO_ERROR;
    const __DRIbackgroundCallableExtension *backgroundCallable =
       screen->sPriv->dri2.backgroundCallable;
 

src/gallium/state_trackers/dri/drisw.c

@@ -371,6 +371,7 @@ static const __DRIextension *drisw_screen_extensions[] = {
    &dri2RendererQueryExtension.base,
    &dri2ConfigQueryExtension.base,
    &dri2FenceExtension.base,
+   &dri2NoErrorExtension.base,
    NULL
 };
 

src/mesa/drivers/dri/common/dri_util.c

@@ -403,7 +403,8 @@ driCreateContextAttribs(__DRIscreen *screen, int api,
     if (mesa_api != API_OPENGL_COMPAT
         && mesa_api != API_OPENGL_CORE
         && (flags & ~(__DRI_CTX_FLAG_DEBUG |
-	              __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS))) {
+	              __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS |
+	              __DRI_CTX_FLAG_NO_ERROR))) {
 	*error = __DRI_CTX_ERROR_BAD_FLAG;
 	return NULL;
     }
@@ -425,7 +426,8 @@ driCreateContextAttribs(__DRIscreen *screen, int api,
 
     const uint32_t allowed_flags = (__DRI_CTX_FLAG_DEBUG
                                     | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
-                                    | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS);
+                                    | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS
+                                    | __DRI_CTX_FLAG_NO_ERROR);
     if (flags & ~allowed_flags) {
 	*error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 	return NULL;
@@ -467,6 +469,8 @@ driContextSetFlags(struct gl_context *ctx, uint32_t flags)
        _mesa_set_debug_state_int(ctx, GL_DEBUG_OUTPUT, GL_TRUE);
         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
     }
+    if ((flags & __DRI_CTX_FLAG_NO_ERROR) != 0)
+        ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_NO_ERROR_BIT_KHR;
 }
 
 static __DRIcontext *
@@ -935,3 +939,7 @@ const __DRIcopySubBufferExtension driCopySubBufferExtension = {
 
    .copySubBuffer               = driCopySubBuffer,
 };
+
+const __DRInoErrorExtension dri2NoErrorExtension = {
+   .base = { __DRI2_NO_ERROR, 1 },
+};

src/mesa/drivers/dri/common/dri_util.h

@@ -293,4 +293,6 @@ driContextSetFlags(struct gl_context *ctx, uint32_t flags);
 
 extern const __DRIimageDriverExtension driImageDriverExtension;
 
+extern const __DRInoErrorExtension dri2NoErrorExtension;
+
 #endif /* _DRI_UTIL_H_ */

src/mesa/drivers/dri/i915/intel_screen.c

@@ -802,6 +802,7 @@ static const __DRIextension *intelScreenExtensions[] = {
     &intelImageExtension.base,
     &intelRendererQueryExtension.base,
     &dri2ConfigQueryExtension.base,
+    &dri2NoErrorExtension.base,
     NULL
 };
 

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

@@ -1274,6 +1274,7 @@ static const __DRIextension *screenExtensions[] = {
     &intelImageExtension.base,
     &intelRendererQueryExtension.base,
     &dri2ConfigQueryExtension.base,
+    &dri2NoErrorExtension.base,
     NULL
 };
 
@@ -1285,6 +1286,7 @@ static const __DRIextension *intelRobustScreenExtensions[] = {
     &intelRendererQueryExtension.base,
     &dri2ConfigQueryExtension.base,
     &dri2Robustness.base,
+    &dri2NoErrorExtension.base,
     NULL
 };
 

src/mesa/drivers/dri/nouveau/nouveau_screen.c

@@ -324,6 +324,7 @@ static const __DRIextension *nouveau_screen_extensions[] = {
     &nouveau_texbuffer_extension.base,
     &nouveau_renderer_query_extension.base,
     &dri2ConfigQueryExtension.base,
+    &dri2NoErrorExtension.base,
     NULL
 };
 

src/mesa/drivers/dri/radeon/radeon_screen.c

@@ -544,6 +544,7 @@ static const __DRIextension *radeon_screen_extensions[] = {
     &radeonFlushExtension.base,
     &radeonImageExtension.base,
     &radeonRendererQueryExtension.base,
+    &dri2NoErrorExtension.base,
     NULL
 };
 

src/mesa/drivers/dri/swrast/swrast.c

@@ -208,6 +208,7 @@ static const __DRI2rendererQueryExtension swrast_query_renderer_extension = {
 static const __DRIextension *dri_screen_extensions[] = {
     &swrastTexBufferExtension.base,
     &swrast_query_renderer_extension.base,
+    &dri2NoErrorExtension.base,
     NULL
 };