Regression from Nim 1.6 to Nim 2.0/devel with generic object and templates

[tersec]

Description

proc log2trunc(x: uint64): int =
  if x == 0: int(0) else: int(0)
template maxChunkIdx(T: typedesc): int64 = 0'i64
template layer(vIdx: int64): int = log2trunc(0'u64)
type HashList[T] = object
  indices: array[int(layer(maxChunkIdx(T))), int]

This compiles on Nim 1.6, but not on either Nim 2.0 or devel.

Nim Version

Nim Compiler Version 1.6.15 [Linux: amd64]
Compiled at 2023-08-16
Copyright (c) 2006-2023 by Andreas Rumpf

git hash: a2521b1dc7efc775b6cf9a299b51eee44fbd3e81
active boot switches: -d:release

Nim Compiler Version 2.0.1 [Linux: amd64]
Compiled at 2023-08-16
Copyright (c) 2006-2023 by Andreas Rumpf

git hash: 037f536e7ee25c4baf23dff8a4525825c506442c
active boot switches: -d:release

Nim Compiler Version 2.1.1 [Linux: amd64]
Compiled at 2023-08-16
Copyright (c) 2006-2023 by Andreas Rumpf

git hash: ade75a148332e670244a719202f7f0337d2e469a
active boot switches: -d:release

Current Output

a.nim(6, 27) Error: type mismatch
Expression: layer(maxChunkIdx(T))
  [1] maxChunkIdx(T): typeof(maxChunkIdx(T))

Expected one of (first mismatch at [position]):
[1] template layer(vIdx: int64): int

Expected Output

No response

Possible Solution

No response

Additional Information

No response

[ringabout]

!nim c

proc log2trunc(x: uint64): int =
  if x == 0: int(0) else: int(0)
template maxChunkIdx(T: typedesc): int64 = 0'i64
template layer(vIdx: int64): int = log2trunc(0'u64)
type HashList[T] = object
  indices: array[int(layer(maxChunkIdx(T))), int]

[github-actions]

@ringabout (member)

devel 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --warnings:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim
/home/runner/work/Nim/Nim/temp.nim(6, 27) Error: type mismatch
Expression: layer(maxChunkIdx(T))
  [1] maxChunkIdx(T): typeof(maxChunkIdx(T))

Expected one of (first mismatch at [position]):
[1] template layer(vIdx: int64): int

Stats

• Started 2023-08-17T01:15:17
• Finished 2023-08-17T01:15:17
• Duration

IR

Compiled filesize 0 bytes (0 bytes)

AST

nnkStmtList.newTree(
  nnkProcDef.newTree(
    newIdentNode("log2trunc"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int"),
      nnkIdentDefs.newTree(
        newIdentNode("x"),
        newIdentNode("uint64"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      nnkIfStmt.newTree(
        nnkElifBranch.newTree(
          nnkInfix.newTree(
            newIdentNode("=="),
            newIdentNode("x"),
            newLit(0)
          ),
          nnkStmtList.newTree(
            nnkCall.newTree(
              newIdentNode("int"),
              newLit(0)
            )
          )
        ),
        nnkElse.newTree(
          nnkStmtList.newTree(
            nnkCall.newTree(
              newIdentNode("int"),
              newLit(0)
            )
          )
        )
      )
    )
  ),
  nnkTemplateDef.newTree(
    newIdentNode("maxChunkIdx"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int64"),
      nnkIdentDefs.newTree(
        newIdentNode("T"),
        newIdentNode("typedesc"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      newLit(0)
    )
  ),
  nnkTemplateDef.newTree(
    newIdentNode("layer"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int"),
      nnkIdentDefs.newTree(
        newIdentNode("vIdx"),
        newIdentNode("int64"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      nnkCall.newTree(
        newIdentNode("log2trunc"),
        nnkUInt64Lit.newTree(
        )
      )
    )
  ),
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("HashList"),
      nnkGenericParams.newTree(
        nnkIdentDefs.newTree(
          newIdentNode("T"),
          newEmptyNode(),
          newEmptyNode()
        )
      ),
      nnkObjectTy.newTree(
        newEmptyNode(),
        newEmptyNode(),
        nnkRecList.newTree(
          nnkIdentDefs.newTree(
            newIdentNode("indices"),
            nnkBracketExpr.newTree(
              newIdentNode("array"),
              nnkCall.newTree(
                newIdentNode("int"),
                nnkCall.newTree(
                  newIdentNode("layer"),
                  nnkCall.newTree(
                    newIdentNode("maxChunkIdx"),
                    newIdentNode("T")
                  )
                )
              ),
              newIdentNode("int")
            ),
            newEmptyNode()
          )
        )
      )
    )
  )
)

stable 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --warnings:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim
/home/runner/work/Nim/Nim/temp.nim(6, 27) Error: type mismatch
Expression: layer(maxChunkIdx(T))
  [1] maxChunkIdx(T): typeof(maxChunkIdx(T))

Expected one of (first mismatch at [position]):
[1] template layer(vIdx: int64): int

Stats

• Started 2023-08-17T01:15:19
• Finished 2023-08-17T01:15:19
• Duration

IR

Compiled filesize 0 bytes (0 bytes)

AST

nnkStmtList.newTree(
  nnkProcDef.newTree(
    newIdentNode("log2trunc"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int"),
      nnkIdentDefs.newTree(
        newIdentNode("x"),
        newIdentNode("uint64"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      nnkIfStmt.newTree(
        nnkElifBranch.newTree(
          nnkInfix.newTree(
            newIdentNode("=="),
            newIdentNode("x"),
            newLit(0)
          ),
          nnkStmtList.newTree(
            nnkCall.newTree(
              newIdentNode("int"),
              newLit(0)
            )
          )
        ),
        nnkElse.newTree(
          nnkStmtList.newTree(
            nnkCall.newTree(
              newIdentNode("int"),
              newLit(0)
            )
          )
        )
      )
    )
  ),
  nnkTemplateDef.newTree(
    newIdentNode("maxChunkIdx"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int64"),
      nnkIdentDefs.newTree(
        newIdentNode("T"),
        newIdentNode("typedesc"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      newLit(0)
    )
  ),
  nnkTemplateDef.newTree(
    newIdentNode("layer"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int"),
      nnkIdentDefs.newTree(
        newIdentNode("vIdx"),
        newIdentNode("int64"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      nnkCall.newTree(
        newIdentNode("log2trunc"),
        nnkUInt64Lit.newTree(
        )
      )
    )
  ),
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("HashList"),
      nnkGenericParams.newTree(
        nnkIdentDefs.newTree(
          newIdentNode("T"),
          newEmptyNode(),
          newEmptyNode()
        )
      ),
      nnkObjectTy.newTree(
        newEmptyNode(),
        newEmptyNode(),
        nnkRecList.newTree(
          nnkIdentDefs.newTree(
            newIdentNode("indices"),
            nnkBracketExpr.newTree(
              newIdentNode("array"),
              nnkCall.newTree(
                newIdentNode("int"),
                nnkCall.newTree(
                  newIdentNode("layer"),
                  nnkCall.newTree(
                    newIdentNode("maxChunkIdx"),
                    newIdentNode("T")
                  )
                )
              ),
              newIdentNode("int")
            ),
            newEmptyNode()
          )
        )
      )
    )
  )
)

2.0.0 👎 FAIL

Output

Error: Command failed: nim c --run  -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --warnings:off --lineTrace:off --nimcache:/home/runner/work/Nim/Nim --out:/home/runner/work/Nim/Nim/temp /home/runner/work/Nim/Nim/temp.nim
/home/runner/work/Nim/Nim/temp.nim(6, 27) Error: type mismatch
Expression: layer(maxChunkIdx(T))
  [1] maxChunkIdx(T): typeof(maxChunkIdx(T))

Expected one of (first mismatch at [position]):
[1] template layer(vIdx: int64): int

Stats

• Started 2023-08-17T01:15:19
• Finished 2023-08-17T01:15:20
• Duration

IR

Compiled filesize 0 bytes (0 bytes)

AST

nnkStmtList.newTree(
  nnkProcDef.newTree(
    newIdentNode("log2trunc"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int"),
      nnkIdentDefs.newTree(
        newIdentNode("x"),
        newIdentNode("uint64"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      nnkIfStmt.newTree(
        nnkElifBranch.newTree(
          nnkInfix.newTree(
            newIdentNode("=="),
            newIdentNode("x"),
            newLit(0)
          ),
          nnkStmtList.newTree(
            nnkCall.newTree(
              newIdentNode("int"),
              newLit(0)
            )
          )
        ),
        nnkElse.newTree(
          nnkStmtList.newTree(
            nnkCall.newTree(
              newIdentNode("int"),
              newLit(0)
            )
          )
        )
      )
    )
  ),
  nnkTemplateDef.newTree(
    newIdentNode("maxChunkIdx"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int64"),
      nnkIdentDefs.newTree(
        newIdentNode("T"),
        newIdentNode("typedesc"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      newLit(0)
    )
  ),
  nnkTemplateDef.newTree(
    newIdentNode("layer"),
    newEmptyNode(),
    newEmptyNode(),
    nnkFormalParams.newTree(
      newIdentNode("int"),
      nnkIdentDefs.newTree(
        newIdentNode("vIdx"),
        newIdentNode("int64"),
        newEmptyNode()
      )
    ),
    newEmptyNode(),
    newEmptyNode(),
    nnkStmtList.newTree(
      nnkCall.newTree(
        newIdentNode("log2trunc"),
        nnkUInt64Lit.newTree(
        )
      )
    )
  ),
  nnkTypeSection.newTree(
    nnkTypeDef.newTree(
      newIdentNode("HashList"),
      nnkGenericParams.newTree(
        nnkIdentDefs.newTree(
          newIdentNode("T"),
          newEmptyNode(),
          newEmptyNode()
        )
      ),
      nnkObjectTy.newTree(
        newEmptyNode(),
        newEmptyNode(),
        nnkRecList.newTree(
          nnkIdentDefs.newTree(
            newIdentNode("indices"),
            nnkBracketExpr.newTree(
              newIdentNode("array"),
              nnkCall.newTree(
                newIdentNode("int"),
                nnkCall.newTree(
                  newIdentNode("layer"),
                  nnkCall.newTree(
                    newIdentNode("maxChunkIdx"),
                    newIdentNode("T")
                  )
                )
              ),
              newIdentNode("int")
            ),
            newEmptyNode()
          )
        )
      )
    )
  )
)

1.6.0 👍 $\color{green}\textbf{\large OK}$

Output

Stats

• Started 2023-08-17T01:15:23
• Finished 2023-08-17T01:15:24
• Duration 1 minutes

1.4.0 👍 $\color{green}\textbf{\large OK}$

Output

Stats

• Started 2023-08-17T01:15:27
• Finished 2023-08-17T01:15:28
• Duration

1.2.0 👍 $\color{green}\textbf{\large OK}$

Output

Stats

• Started 2023-08-17T01:15:44
• Finished 2023-08-17T01:15:45
• Duration

1.0.0 👍 $\color{green}\textbf{\large OK}$

Output

Stats

• Started 2023-08-17T01:15:58
• Finished 2023-08-17T01:15:58
• Duration

0.20.2 👍 $\color{green}\textbf{\large OK}$

Output

Stats

• Started 2023-08-17T01:16:13
• Finished 2023-08-17T01:16:13
• Duration

#894a19c6e ➡️ 🐛

Diagnostics

metagn introduced a bug at 2023-06-13 21:05:44 +0300 on commit #894a19c6e with message:

fix calls in generic bodies, delay typecheck when no overloads match (#22029)

* sacrifice "tgenericshardcases" for working statics

* legacy switch for CI, maybe experimental later

* convert to experimental

* apparently untyped needs the experimental switch

* try special case call semcheck

* try fix

* fix compilation

* final cleanup, not experimental, make `when` work

* remove last needed use of untyped

* fix unused warning in test

* remove untyped feature

The bug is in the files:

compiler/semcall.nim
compiler/semexprs.nim
compiler/seminst.nim
compiler/semtypes.nim
compiler/semtypinst.nim
compiler/sigmatch.nim
compiler/types.nim
tests/generics/tgenerics_various.nim
tests/generics/tuninstantiatedgenericcalls.nim
tests/statictypes/tgenericcomputedrange.nim
tests/statictypes/tstaticgenericparam.nim

The bug can be in the commits:

• #44f377eda
• #20dfdba2d
• #894a19c6e
• #606e9941d
• #cca5e5ffb
• #fda8b6f19
• #2e12d3e26

(Diagnostics sometimes off-by-one).

Stats

• GCC 11.4.0
• LibC 2.35
• Valgrind 3.18.1
• NodeJS 17.0
• Linux 5.15.0
• Created 2023-08-17T01:14:30Z
• Comments 1
• Commands nim c --run -d:nimDebugDlOpen -d:ssl -d:nimDisableCertificateValidation --forceBuild:on --colors:off --verbosity:0 --hints:off --warnings: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 47 minutes bisecting 1704 commits at 36 commits per second.

[metagn]

The fix is probably to extend the logic for calls added in #22029 to type conversions (semConv), that is, generate tyFromExpr for tyFromExpr

Might be as simple as changing this: https://github.com/nim-lang/Nim/blob/299394d21a3b7f2af02c8cdede1dcd0cd5948a0e/compiler/semexprs.nim#L376 to if targetType.kind in {tyGenericParam, tyFromExpr}