LibJS: More properly implement scoping rules in bytecode codegen

Now we emit CreateVariable and SetVariable with the appropriate initialization/environment modes, much closer to the spec. This makes a whole lot of things like let/const variables, function and variable hoisting and some other things work :^)
Author: https://github.com/alimpfard Commit: 1bbfaf8627 Pull-request: https://github.com/SerenityOS/serenity/pull/12468 Reviewed-by: https://github.com/linusg ✅
2025-09-02 15:46:33 +00:00 · 2022-02-12 19:48:45 +03:30 · 2022-02-12 19:48:45 +03:30 · 1bbfaf8627 · 2024-07-17 18:55:09 +09:00
commit 1bbfaf8627
parent c7e6b65fd2
12 changed files with 503 additions and 38 deletions
--- a/Userland/Libraries/LibJS/Bytecode/Instruction.h
+++ b/Userland/Libraries/LibJS/Bytecode/Instruction.h
@ -20,6 +20,8 @@
    O(ConcatString)                  \
    O(ContinuePendingUnwind)         \
    O(CopyObjectExcludingProperties) \
+    O(CreateEnvironment)             \
+    O(CreateVariable)                \
    O(Decrement)                     \
    O(Div)                           \
    O(EnterUnwindContext)            \
@ -42,6 +44,7 @@
    O(JumpConditional)               \
    O(JumpNullish)                   \
    O(JumpUndefined)                 \
+    O(LeaveEnvironment)              \
    O(LeaveUnwindContext)            \
    O(LeftShift)                     \
    O(LessThan)                      \