OSL files fail to compile when shader ends with a comment #77603

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Michael Macha · 2020-06-08T07:40:23+02:00

Michael Macha commented

2020-06-08 07:40:23 +02:00

System Information
Operating system: Linux Mint 19.10
Graphics card: Nvidia GTX 950, 4 GB VRAM

Blender Version
Broken: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: 211b6c29f7, type: Release
Worked: unknown

OSL permits comments virtually anywhere in the file, by specification; yet when I trail a '//' at the end of my file, Blender fails to compile the shader.

Attempt this basic OSL file, after switching the default startup model to Cycles, selecting the CPU, and turning on OSL.

shader shade(output color cOut = color(1, 0, 0)) {
}

It should simply have one output node with the default color red, and should compile fine. (Adding a material to the cube and connecting the output to color should turn it red.) Now, try this, verbatim.

shader shade(output color cOut = color(1, 0, 0)) {
}
//some random comment

and, attempt to recompile. Blender fails, with the terminal message:

ERROR: /tmp/tmp0ary5am_.osl:3: error: preprocessor exception caught: boost::wave::lexing_exception
Error: OSL script compilation failed, see console for errors

The workaround is easy enough; I just leave my notes somewhere more amicable to Cycles' lexer when taking them in comments. (Placing them at the beginning, instead of the end, as an example.) However, it seems the lexer is failing here, and does not expect to encounter a comment at the end of the file, which feels like a mistake.

**System Information** Operating system: Linux Mint 19.10 Graphics card: Nvidia GTX 950, 4 GB VRAM **Blender Version** Broken: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: 211b6c29f771, type: Release Worked: unknown OSL permits comments virtually anywhere in the file, by specification; yet when I trail a '//' at the end of my file, Blender fails to compile the shader. Attempt this basic OSL file, after switching the default startup model to Cycles, selecting the CPU, and turning on OSL. ``` shader shade(output color cOut = color(1, 0, 0)) { } ``` It should simply have one output node with the default color red, and should compile fine. (Adding a material to the cube and connecting the output to color should turn it red.) Now, try this, verbatim. ``` shader shade(output color cOut = color(1, 0, 0)) { } //some random comment ``` and, attempt to recompile. Blender fails, with the terminal message: ``` ERROR: /tmp/tmp0ary5am_.osl:3: error: preprocessor exception caught: boost::wave::lexing_exception Error: OSL script compilation failed, see console for errors ``` The workaround is easy enough; I just leave my notes somewhere more amicable to Cycles' lexer when taking them in comments. (Placing them at the beginning, instead of the end, as an example.) However, it seems the lexer is failing here, and does not expect to encounter a comment at the end of the file, which feels like a mistake.

Michael Macha commented

2020-06-08 07:40:23 +02:00

Added subscriber: @Michael_Macha