Bug 101247

Summary:	Mesa fails to link GLSL programs with unused output blocks
Product:	Mesa	Reporter:	Józef Kucia <joseph.kucia>
Component:	glsl-compiler	Assignee:	mesa-dev
Status:	RESOLVED FIXED	QA Contact:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity:	normal
Priority:	medium
Version:	git
Hardware:	All
OS:	All
See Also:	https://bugs.winehq.org/show_bug.cgi?id=43057
Whiteboard:
i915 platform:		i915 features:

Description Józef Kucia 2017-05-31 11:42:16 UTC

Mesa fails to link GLSL programs with unused output blocks declared in a shader object other than the main one.

piglit: https://lists.freedesktop.org/archives/piglit/2017-May/022302.html

This bugs affects multiple application in Wine when GL core profiles are enabled.

Comment 1 Samuel Pitoiset 2017-05-31 13:02:16 UTC

Thanks for reporting this. I saw your piglit test yesterday. It's a bug yes.

Comment 2 vadym 2018-08-22 11:19:09 UTC

Patch: https://patchwork.freedesktop.org/patch/245518/

Comment 3 vadym 2018-08-27 10:37:00 UTC

Patch merged to master:

commit 4a8444d5bc865119218eca8674e5614535f4829e (HEAD -> new_master, origin/master, origin/HEAD)
Author: vadym.shovkoplias <vadim.shovkoplias@gmail.com>
Date:   Thu Aug 23 13:12:16 2018 +0300

    glsl/linker: Allow unused in blocks which are not declated on previous stage
    
    >From Section 4.3.4 (Inputs) of the GLSL 1.50 spec:
    
        "Only the input variables that are actually read need to be written
         by the previous stage; it is allowed to have superfluous
         declarations of input variables."
    
    Fixes:
        * interstage-multiple-shader-objects.shader_test
    
    v2:
      Update comment in ir.h since the usage of "used" field
      has been extended.
    
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101247
    Signed-off-by: Vadym Shovkoplias <vadym.shovkoplias@globallogic.com>
    Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
    Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

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