(add) balde: add --disable-elide-loops and --help

nim.cfg

@@ -2,7 +2,6 @@
 
 # Bali-specific flags
 # --define:baliUseStdBase64 # Instead of simdutf's SIMD accelerated base64 encoder/decoder, use the (slower) ones in the Nim standard library.
-# --define:baliEmitterDontElideLoops # Don't try eliding loops whenever possible
 
 # Enable SIMD support
 --passC: "-march=znver3 -mtune=znver3 -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -mpclmul -mavx -mavx2"

src/balde.nim

@@ -52,7 +52,14 @@ proc die(msg: varargs[string]) {.inline, noReturn.} =
 proc allocRuntime*(ctx: Input, file: string, ast: AST, repl: bool = false): Runtime =
   let test262 = ctx.enabled("test262")
   var runtime = newRuntime(
-    file, ast, InterpreterOpts(test262: test262, dumpBytecode: ctx.enabled("dump-bytecode"), repl: repl)
+    file, ast, InterpreterOpts(
+      test262: test262,
+      dumpBytecode: ctx.enabled("dump-bytecode", "D"),
+      repl: repl,
+      codegen: CodegenOpts(
+        elideLoops: not ctx.enabled("disable-loop-elision")
+      )
+    )
   )
   let expStr = ctx.flag("enable-experiments")
 
@@ -107,7 +114,7 @@ proc execFile(ctx: Input, file: string) {.inline.} =
         die "failed to open file:", exc.msg
         ""
 
-  if ctx.enabled("dump-tokens"):
+  if ctx.enabled("dump-tokens", "T"):
     let excludeWs = ctx.enabled("no-whitespace")
     let tok = newTokenizer(source)
     while not tok.eof:
@@ -280,6 +287,31 @@ You can also just type in JavaScript expressions to evaluate them."""
   when promptHistory:
     discard noise.historySave(file)
 
+proc showHelp {.noReturn.} =
+  let name = getAppFilename().splitPath().tail
+  echo """
+Usage: $1 [options] [script]
+
+  The Bali Debugger provides a command line interface to the Bali JavaScript engine.
+  If no files are provided for execution, then Balde starts a read-eval-print-loop (REPL)
+  session.
+
+Version: $2
+
+Options:
+  --help, -h                              Show this message.
+  --verbose, -v                           Show additional debug logs, useful for debugging the engine.
+  --dump-bytecode, -D                     Dump bytecode for the next evaluation.
+  --dump-tokens, -T                       Dump tokens for the provided file.
+  --dump-ast                              Dump the abstract syntax tree for the JavaScript file.
+  --dump-no-eval                          Dump the abstract syntax tree for the JavaScript file, bypassing the IR generation phase entirely.
+  --disable-loop-elision                  Don't attempt to elide loops in the IR generation phase.
+  --enable-experiments:<a>;<b>; ... <z>   Enable certain experimental features that aren't stable yet.
+""" % [
+  name, Version
+  ]
+  quit(0)
+
 proc main() {.inline.} =
   enableLogging()
 
@@ -291,6 +323,9 @@ proc main() {.inline.} =
   if input.enabled("verbose", "v"):
     setLogFilter(lvlAll)
 
+  if input.enabled("help", "h"):
+    showHelp()
+
   if input.command.len < 1:
     if not input.enabled("verbose", "v"):
       setLogFilter(lvlError)

src/bali/runtime/interpreter.nim

@@ -590,13 +590,12 @@ proc generateIR*(
     runtime.ir.copyAtom(runtime.index(stmt.cpImmutSourceIdent, defaultParams(fn)), dest)
   of WhileStmt:
     debug "emitter: generate IR for while loop"
-    when not defined(baliEmitterDontElideLoops):
-      if stmt.whStmtOnlyMutatesItsState(stmt.whBranch.getValueCaptures()):
-        debug "emitter: while loop only mutates its own state - eliding it away"
-        if runtime.optimizeAwayStateMutatorLoop(fn, stmt):
-          return  # we can fully skip creating all of the expensive comparison checks! :D
-        else:
-          warn "emitter: failed to elide state mutator loop :("
+    if runtime.opts.codegen.elideLoops and stmt.whStmtOnlyMutatesItsState(stmt.whBranch.getValueCaptures()):
+      debug "emitter: while loop only mutates its own state - eliding it away"
+      if runtime.optimizeAwayStateMutatorLoop(fn, stmt):
+        return  # we can fully skip creating all of the expensive comparison checks! :D
+      else:
+        debug "emitter: failed to elide state mutator loop :("
 
     runtime.expand(fn, stmt)
 

src/bali/runtime/types.nim

@@ -50,11 +50,15 @@ type
   ExperimentOpts* = object
     dateRoutines*: bool
 
+  CodegenOpts* = object
+    elideLoops*: bool = true
+
   InterpreterOpts* = object
     test262*: bool = false
     repl*: bool = false
     dumpBytecode*: bool = false
-
+
+    codegen*: CodegenOpts
     experiments*: ExperimentOpts
 
   JSType* = object

src/bali/stdlib/types/std_string.nim

@@ -111,8 +111,6 @@ proc generateStdIr*(runtime: Runtime) =
         res &= nextString
 
       # 5. Return R.
-      echo runtime.argumentcount
-      echo res
       ret res
   )
 

tests/data/string-concat-001.js

@@ -10,6 +10,7 @@ var i = 0
 while (i < 4)
 {
 	let val = vals[i]
-	console.log(x.concat(val))
+	let cat = x.concat(val)
+	console.log(cat)
 	i++
 }