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| author | metagn <metagngn@gmail.com> | 2024-09-03 06:45:08 +0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-09-03 05:45:08 +0200 |
| commit | d27061f6dabf99255dd677595bed1d9a97ec135e (patch) | |
| tree | 9503991fe2f17960b187be32790928527f3076c0 | |
| parent | 71de7fca9e97d149a150ff6bc08875ba458b178b (diff) | |
| download | Nim-d27061f6dabf99255dd677595bed1d9a97ec135e.tar.gz | |
fix segfault with gensym node instantiation (#24050)
fixes #24048 Generic lambdas get instantiated via `replaceTypesInBody` which calls `replaceTypeVarsN` on the body of the lambda. This body can contain sym nodes of gensym symbols generated by macros, which have `nil` type. But a piece of code in `replaceTypeVarsN` checks whether the type of a symbol is equal to `void` without checking if it's `nil` first, which causes a segfault. Now it also checks that the type of the symbol isn't `nil` for it to be `void`.
| -rw-r--r-- | compiler/semtypinst.nim | 3 | ||||
| -rw-r--r-- | tests/generics/tgensyminst.nim | 29 |
2 files changed, 31 insertions, 1 deletions
diff --git a/compiler/semtypinst.nim b/compiler/semtypinst.nim index 47fdc162d..c2599c6f7 100644 --- a/compiler/semtypinst.nim +++ b/compiler/semtypinst.nim @@ -290,7 +290,8 @@ proc replaceTypeVarsN(cl: var TReplTypeVars, n: PNode; start=0; expectedType: PT replaceTypeVarsS(cl, n.sym, result.typ) else: replaceTypeVarsS(cl, n.sym, replaceTypeVarsT(cl, n.sym.typ)) - if result.sym.typ.kind == tyVoid: + # sym type can be nil if was gensym created by macro, see #24048 + if result.sym.typ != nil and result.sym.typ.kind == tyVoid: # don't add the 'void' field result = newNodeI(nkRecList, n.info) of nkRecWhen: diff --git a/tests/generics/tgensyminst.nim b/tests/generics/tgensyminst.nim new file mode 100644 index 000000000..3f30188d8 --- /dev/null +++ b/tests/generics/tgensyminst.nim @@ -0,0 +1,29 @@ +# issue #24048 + +import macros + +proc map(fn: proc(val: int): void) = fn(1) + +# This works fine, and is the exact same function call as what's +# generated by the macro `aBug`. +map proc(val: auto): void = + let variable = 123 + +macro aBug() = + # 1. let sym = ident("variable") + let sym = genSym(nskLet, "variable") + let letStmt = newLetStmt(sym, newLit(123)) + + let lambda = newProc( + params = @[ + ident("void"), + newIdentDefs(ident("val"), ident("auto")), + # 2. newIdentDefs(ident("val"), ident("int")), + ], + body = newStmtList(letStmt), + procType = nnkLambda + ) + + result = newCall(bindSym("map"), lambda) + +aBug() |