Does not work if target language is C++

[NotoriousRebel]

Hello, I recently wanted to use this for a project I was working on. However, with the first example in the readme it works great when the target language is C but not when it's C++. I do not have a stack trace available as it does not provide one when compiling as C++.

[NotoriousRebel]

For some more detail this is on Windows Version 20H2 and Nim 1.4.2. Also is x86 supported? Doesn't seem to compile if targeting x86.

[krux02]

I just tried the examples with C and C++. No problems on my machine. I however use Linux, not Windows. This library doesn't use ancy fancy trickery that would break x86, so that one should work out of the box.

Can you post the exact code that you used for testing and the generated C++ code? My first guess would be that it is a regression in the Nim compiler.

[krux02]

on my system, the generated c++ code for /tmp/scratch.nim, is stored under /home/arne/.cache/nim/scratch_d/@mscratch.nim.cpp. There should be an equivalent path on your system, too.

[krux02]

Since I don't have Windows, I can't reproduce the problem. Maybe somebody else can. Maybe you can reproduce the problem in an online compiler Nim compiler, so I might be able to address the problem there.

If I don't hear back from you I might close this issue as not reproduceable.

[NotoriousRebel]

@krux02 Apologies for the late response here is the example code with error logs:

Here is the example code I am using:

The files math, vec, and quat are the nim files from the repo in nim-glm/glm folder.

import mat
import vec
import quat
import math

proc lookAtRH[T](eye,center,up:Vec3[T]): Mat4[T] =
    let
        f = normalize(center - eye)
        s = normalize(cross(f, up))
        u = cross(s,f)
    result = mat4[T](1.0)
    result.row0 = vec4( s,0)
    result.row1 = vec4( u,0)
    result.row2 = vec4(-f,0)
    result.arr[3] = vec4(-dot(s,eye), -dot(u,eye), dot(f,eye), 1)
    result[3,0] = -dot(s, eye)
    result[3,1] = -dot(u, eye)
    result[3,2] = dot(f, eye)

proc perspectiveRH[T]( fovy, aspect, zNear, zFar:T): Mat4[T] =
    let tanHalfFovy = tan(fovy / T(2))
    result = mat4[T](0.0)
    result[0,0] = T(1) / (aspect * tanHalfFovy)
    result[1,1] = T(1) / (tanHalfFovy)
    result[2,3] = T(-1)

    result[2,2] = -(zFar + zNear) / (zFar - zNear)
    result[3,2] = -(T(2) * zFar * zNear) / (zFar - zNear)

proc perspective*[T]( fovy, aspect, zNear, zFar:T):Mat4[T]=
    perspectiveRH(fovy, aspect, zNear, zFar)
proc lookAt*[T](eye,center,up:Vec3[T]):Mat4[T]=
    lookAtRH(eye, center, up)

proc Calculate(): int =
    var
        v = vec3(1.0, 5.0, 6.0)
        a = vec3(2.0, 2.0, 5.0)
        v4 = vec4(v, 1.0)
        c = cross(v,a)
        # m = rotate(mat4d(), 5.0, vec3(1.0, 0.0, 0.0))
        # r = v4 * c
    echo "a: "
    echo $a
    var
        eye = vec3(50.0, 50.0, 10.0)
        center = vec3(0.0)
        up = vec3(0.0, 1.0, 0.0)
        viewMatrix = lookAt(eye, center, up)
        # math.PI
        projectionMat = perspective(4/2, 1.0, 0.01, 100.0)

    echo viewMatrix * projectionMat
    # TODO replace result with matrix[1][1]
    result =  1

var res = Calculate()
echo $res

This is how I am compiling it:

nim c -r --d:release --opt:size --cpu:i386 .\calculate.nim

and the error logs:

In file included from C:\Users\john\nimcache\calculate_r\stdlib_dollars.nim.c:11:0:
C:\Users\john\.choosenim\toolchains\nim-1.4.2\lib/nimbase.h:271:35: error: static assertion failed: ""
 #define NIM_STATIC_ASSERT(x, msg) _Static_assert((x), msg)
                                   ^
C:\Users\john\.choosenim\toolchains\nim-1.4.2\lib/nimbase.h:542:1: note: in expansion of macro 'NIM_STATIC_ASSERT'
 NIM_STATIC_ASSERT(sizeof(NI) == sizeof(void*) && NIM_INTBITS == sizeof(NI)*8, "");
 ^~~~~~~~~~~~~~~~~
In file included from C:\Users\john\nimcache\calculate_r\stdlib_assertions.nim.c:11:0:
C:\Users\john\.choosenim\toolchains\nim-1.4.2\lib/nimbase.h:271:35: error: static assertion failed: ""
 #define NIM_STATIC_ASSERT(x, msg) _Static_assert((x), msg)
                                   ^
C:\Users\john\.choosenim\toolchains\nim-1.4.2\lib/nimbase.h:542:1: note: in expansion of macro 'NIM_STATIC_ASSERT'
 NIM_STATIC_ASSERT(sizeof(NI) == sizeof(void*) && NIM_INTBITS == sizeof(NI)*8, "");
 ^~~~~~~~~~~~~~~~~
Error: execution of an external compiler program 'gcc.exe -c  -w -fmax-errors=3 -mno-ms-bitfields -masm=intel -Os -fno-ident   -IC:\Users\john\.choosenim\toolchains\nim-1.4.2\lib -IC:\NimMathTest -o C:\Users\john\nimcache\calculate_r\stdlib_dollars.nim.c.o C:\Users\john\nimcache\calculate_r\stdlib_dollars.nim.c' failed with exit code: 1

When compiling for x64 and the target language is C the program works just fine.

nim cpp -r --d:release --opt:size .\calculate.nim

When the target language is C++ this is the error log (all I see):

Error: execution of an external program failed: 'C:\NimMathTest\calculate.exe'

I will test on Linux sometime this week.

[krux02]

Can you post the content of these three files from your system after you got the problem:

• C:\Users\john\.choosenim\toolchains\nim-1.4.2\lib\nimbase.h
• C:\Users\john\nimcache\calculate_r\stdlib_assertions.nim.c
• C:\Users\john\nimcache\calculate_r\stdlib_dollars.nim.c

I think that should be enough for me to remote diagnose the problem.