Segmentation fault upon compilation with recursive typeclass definitions

[tersec]

Description

Simple version:

type
  A = A | B
  B = A | B
discard 0 is A

But it scales to where it's nontrivial to spot the cycles on observation, even with all the typeclasses right there:

type
  A = K | C
  B = J | A
  C = H | R
  D = T | S
  E = W | O
  F = M | S
  G = X | B
  H = P | Q
  I = W | G
  J = I | E
  K = U | O
  L = X | D
  M = B | N
  N = R | L
  O = L | Q
  P = V | F
  Q = A | N
  R = H | E
  S = J | M
  T = I | P
  U = F | T
  V = D | C
  W = K | G
  X = V | U
discard 0 is M

Adding concrete terminal types doesn't work around it:

type
  S = A | C
  N = W | F
  L = object
  C = object
  E = V | K
  X = Y | M
  W = object
  P = object
  V = B | H
  F = object
  B = U | E
  D = S | J
  M = object
  A = object
  H = object
  U = X | D
  Y = L | T
  J = object
  T = object
  K = N | P
discard 0 is E

Nim Version

Nim Compiler Version 2.0.10 [Linux: amd64]
Compiled at 2024-08-01
Copyright (c) 2006-2023 by Andreas Rumpf

git hash: 92e505577e8b6b9214b6fcdd7fe1b0e9a244023b
active boot switches: -d:release

Nim Compiler Version 2.1.9 [Linux: amd64]
Compiled at 2024-08-01
Copyright (c) 2006-2024 by Andreas Rumpf

git hash: cb156648d69fd0c21ee5d041a98ddc69294eaa96
active boot switches: -d:release

Current Output

.....................................................................Segmentation fault

Expected Output

No Segmentation fault

Possible Solution

No response

Additional Information

No response

[juancarlospaco]

!nim c

type
  A = A | B
  B = A | B
discard 0 is A

[github-actions]

🐧 Linux bisect by @juancarlospaco (collaborator)

devel 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:28:50
• Finished 2024-08-01T10:28:51
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

stable 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:28:54
• Finished 2024-08-01T10:28:55
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

2.0.4 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:28:57
• Finished 2024-08-01T10:28:58
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

2.0.0 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:29:01
• Finished 2024-08-01T10:29:01
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

1.6.20 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:29:04
• Finished 2024-08-01T10:29:04
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

1.4.8 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:29:07
• Finished 2024-08-01T10:29:07
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

1.2.18 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:29:09
• Finished 2024-08-01T10:29:09
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

1.0.10 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

IR

Compiled filesize 0 (0 bytes)

Stats

• Started 2024-08-01T10:29:12
• Finished 2024-08-01T10:29:12
• Duration

AST

nnkStmtList.newTree(
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("A"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    ),
    nnkTypeDef.newTree(
      newIdentNode("B"),
      newEmptyNode(),
      nnkInfix.newTree(
        newIdentNode("|"),
        newIdentNode("A"),
        newIdentNode("B")
      )
    )
  ),
  nnkDiscardStmt.newTree(
    nnkInfix.newTree(
      newIdentNode("is"),
      newLit(0),
      newIdentNode("A")
    )
  )
)

Stats

• GCC 11.4.0
• Clang 14.0.0
• NodeJS 20.4
• Created 2024-08-01T10:28:24Z
• Comments 1
• Commands nim c --run -d:nimDebug -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim

🤖 Bug found in 25 minutes bisecting 8 commits at 0 commits per second