Splicing a tuple into an indexed literal causes subsequent form to compile incorrectly

[ianthehenry]

Interesting bug where it seems like a splice is persisting after the expression it occurs in. This program:

(defn main [&]
  (def a [1 2 3])
  (def b [;a])
  (pp a))

Raises with error: <function pp> called with 4 arguments, expected 1. Commenting out the line with the splice causes it to work as expected.

Tested on Janet 1.32.1-cc5beda0 macos/aarch64/clang.

The following variations do not have the bug:

(defn main [&]
  (def a [1 2 3])
  (def b (tuple ;a))
  (pp a))

(defn main [&]
  (def a [1 2 3])
  (def b [;[1 2 3]])
  (pp a))

(defn main [&]
  (def a @[1 2 3])
  (def b [;a])
  (pp a))

Though this one also fails:

(defn main [&]
  (def a [1 2 3])
  (def b @[;a])
  (pp a))

[sogaiu]

Confirmed in Janet 1.32.1-56f33f51 linux/x64/gcc and Janet 1.32.1-9593c930 linux/x64/gcc.

[sogaiu]

Fails in:

• 5a39a04a
• 77189b6e
• fcca9bba

Works ok in:

• dbb21874
• 358f5a03

May be it's https://github.com/janet-lang/janet/commit/fcca9bbab3d64ed51259745dec2dfaffcc20c3d1, as the commit before it, dbb21874, seems to be ok.

[bakpakin]

Pushed a fix in a9176a77e6a93a5e10b5c069e9b1c88d4b25e40e - the issue seems to be that certain bytecode instructions were being aggressively optimized out despite have side effects (clearing the call stack), making the next function call get extra arguments.

[sogaiu]

All of the reported examples work fine here now :+1: