I can't think of any complex game codebase I worked on that has shaders all in one file. They all need #include support. When I try to compile our GL shaders (really Vulkan), I get the following failures. Can I use this offline compiler on real .vert and .frag files? I'm trying to figure out why Mali driver puts out VK_DEVICE_LOST on our terrain shaders, and thought seeing the shader analysis might help.
malioc -c Mali-G76 --vulkan --vertex DebugMesh.vert
ERROR: 0X0000: SPIR-V require version 310 or higher. <- fixed below
ERROR: 0:4: X0000: '#include' : required extension not requested: GL_GOOGLE_include_directive
ERROR: 0:4: X0000: '#include' : must be followed by a header name
ERROR: 0ssing entry point: X0000: Each stage requires one entry point <- printing problem
After putting #version 310 es at the top of the file. We don't typically do this, since we need to compile the shaders using spriv-opt for many different versions. There also doesn't seem to be a compile option for this.
ERROR: 0ssing entry point: X0000: Each stage requires one entry point. <- how to specify this ?
Here are the reported extensions, but include support isn't in there.
Vulkan SPIR-V Extensions
Hi Alec, Thanks for the feedback.
Alec said:ERROR: 0X0000: SPIR-V require version 310 or higher. <- fixed below
The 0X* errors are directly reported from the Khronos glslangValidator application, which we use for converting GLSL into SPIR-V.
The extension support needed for include directives is part of glslangValidator, which is why we don't report it directly, as it's not a SPIR-V extension that our compiler would see. I'll see what is needed to get this working (suspect it might be looking in the current working directory, not the source directory, so we might need to add a way to specify and forward include paths to the child process).
We could probably automatically inject the #version specifier if it's missing, and add a warning that we did so. As Pavel mentioned we just concatenate N input files, so you could just create a single utility file containing the version and include preamble you need, and specify this first on the command line.
Alec said:ERROR: 0ssing entry point: X0000: Each stage requires one entry point <- printing problem
Thanks, looks like we're not hiding some of the original log from the glslangValidator, so we're getting to processes writing out to the console. Will raise a bug for this one.
Alec said:ERROR: 0ssing entry point: X0000: Each stage requires one entry point. <- how to specify this ?
Hmm, shaders with a default "main" should work. Do the non-spirv samples we ship in the samples/vulkan/ directory work for you? If it's possible can you share the problem shader (drop me an email, as I assume you can't share here)?
Alec said:Shouldn't the compiler tell me how many varyings a shader uses if that's critical to the 180MB limit on Mali driver? I don't see anything related to that in the output.
At the moment we don't emit this. Agree it would be useful. Will raise an enhancement with the team.
We use shaderc for spriv compilation, and it performs much better than glslangValidator. It injects the version and extension depending on the compile parameters, so we can't have #version at the top of each file. Tried to switch our codebase over to glslangValidator since that supported Vulkan version number, and hit numerous problems with that compiler.
One of the biggest issues was that error formatting isn't clickable coming out of glslangValidator. So now I maintain a shader project that can generate all shader for all platforms and clickthrough to errors/warnings.
It's fine that I can pass the .spv files. The downside is we often transpile to Metal, and spirv-opt strips all commentary from the files. That despite that it has embedded shaders with comments and OpLine directives in the compile source that it could reference to grab the comments.
A bit more investigation here on the Mali Offline Compiler 7.4 (will ship at the end of the month).
Using includes does work for glslang (with the #extension added), but only the current working directory is on the include search path. Any includes relative to the source shader location will only work if the source shader is in the current working directory when the offline compiler is invoked.
We do have all our sources/headers in a single folder. But for now we're using spv for the analysis since it's already spliced together into a single file. Thanks for the followup.