diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Macros.scala | 62 |
1 files changed, 35 insertions, 27 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala index 27920dbd74..afefc39b0e 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala @@ -600,39 +600,47 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { } /** Expands a term macro used in apply role as `M(2)(3)` in `val x = M(2)(3)`. + * @param outerPt Expected type that comes from enclosing context (something that's traditionally called `pt`). + * @param innerPt Expected type that comes from the signature of a macro def, possibly wildcarded to help type inference. * @see MacroExpander */ - def macroExpandApply(typer: Typer, expandee: Tree, mode: Mode, pt: Type): Tree = { - object expander extends TermMacroExpander(APPLY_ROLE, typer, expandee, mode, pt) { - override def onSuccess(expanded0: Tree) = { - def approximate(tp: Type) = { + def macroExpandApply(typer: Typer, expandee: Tree, mode: Mode, outerPt: Type): Tree = { + object expander extends TermMacroExpander(APPLY_ROLE, typer, expandee, mode, outerPt) { + lazy val innerPt = { + val tp = if (isNullaryInvocation(expandee)) expandee.tpe.finalResultType else expandee.tpe + if (isBlackbox(expandee)) tp + else { // approximation is necessary for whitebox macros to guide type inference // read more in the comments for onDelayed below - if (isBlackbox(expandee)) tp + val undetparams = tp collect { case tp if tp.typeSymbol.isTypeParameter => tp.typeSymbol } + deriveTypeWithWildcards(undetparams)(tp) + } + } + override def onSuccess(expanded0: Tree) = { + // prematurely annotate the tree with a macro expansion attachment + // so that adapt called indirectly by typer.typed knows that it needs to apply the existential fixup + linkExpandeeAndExpanded(expandee, expanded0) + + def typecheck(label: String, tree: Tree, pt: Type): Tree = { + if (tree.isErrorTyped) tree else { - val undetparams = tp collect { case tp if tp.typeSymbol.isTypeParameter => tp.typeSymbol } - deriveTypeWithWildcards(undetparams)(tp) + if (macroDebugVerbose) println(s"$label (against pt = $pt): $tree") + // `macroExpandApply` is called from `adapt`, where implicit conversions are disabled + // therefore we need to re-enable the conversions back temporarily + val result = typer.context.withImplicitsEnabled(typer.typed(tree, mode, pt)) + if (result.isErrorTyped && macroDebugVerbose) println(s"$label has failed: ${typer.context.reportBuffer.errors}") + result } } - val macroPt = approximate(if (isNullaryInvocation(expandee)) expandee.tpe.finalResultType else expandee.tpe) - val expanded = if (isBlackbox(expandee)) atPos(enclosingMacroPosition.focus)(Typed(expanded0, TypeTree(macroPt))) else expanded0 - // prematurely annotate the tree with a macro expansion attachment - // so that adapt called indirectly by typer.typed knows that it needs to apply the existential fixup - linkExpandeeAndExpanded(expandee, expanded) - - // `macroExpandApply` is called from `adapt`, where implicit conversions are disabled - // therefore we need to re-enable the conversions back temporarily - if (macroDebugVerbose) println(s"typecheck #1 (against macroPt = $macroPt): $expanded") - val expanded1 = typer.context.withImplicitsEnabled(typer.typed(expanded, mode, macroPt)) - if (expanded1.isErrorTyped) { - if (macroDebugVerbose) println(s"typecheck #1 has failed: ${typer.context.reportBuffer.errors}") - expanded1 + if (isBlackbox(expandee)) { + val expanded1 = atPos(enclosingMacroPosition.focus)(Typed(expanded0, TypeTree(innerPt))) + val expanded2 = typecheck("blackbox typecheck #1", expanded1, innerPt) + typecheck("blackbox typecheck #2", expanded1, outerPt) } else { - if (macroDebugVerbose) println(s"typecheck #2 (against pt = $pt): $expanded1") - val expanded2 = typer.context.withImplicitsEnabled(super.onSuccess(expanded1)) - if (macroDebugVerbose && expanded2.isErrorTyped) println(s"typecheck #2 has failed: ${typer.context.reportBuffer.errors}") - expanded2 + val expanded1 = expanded0 + val expanded2 = typecheck("whitebox typecheck #1", expanded1, innerPt) + typecheck("whitebox typecheck #2", expanded2, outerPt) } } override def onDelayed(delayed: Tree) = { @@ -686,11 +694,11 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { // Thanks to that the materializer can take a look at what's going on and react accordingly. val shouldInstantiate = typer.context.undetparams.nonEmpty && !mode.inPolyMode if (shouldInstantiate) { - if (isBlackbox(expandee)) typer.instantiatePossiblyExpectingUnit(delayed, mode, pt) + if (isBlackbox(expandee)) typer.instantiatePossiblyExpectingUnit(delayed, mode, outerPt) else { forced += delayed - typer.infer.inferExprInstance(delayed, typer.context.extractUndetparams(), pt, keepNothings = false) - macroExpandApply(typer, delayed, mode, pt) + typer.infer.inferExprInstance(delayed, typer.context.extractUndetparams(), outerPt, keepNothings = false) + macroExpandApply(typer, delayed, mode, outerPt) } } else delayed } |