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nicolasstuckinicolasstucki
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Split macro body checks from interpreter
1 parent cc2c34b commit 6d9f314

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2 files changed

+165
-147
lines changed

2 files changed

+165
-147
lines changed

‎compiler/src/dotty/tools/dotc/transform/Splicer.scala

Lines changed: 151 additions & 137 deletions
Original file line numberDiff line numberDiff line change
@@ -64,15 +64,82 @@ object Splicer {
6464
*/
6565
def checkValidMacroBody(tree: Tree)(implicit ctx: Context): Unit = tree match {
6666
case Quoted(_) => // ok
67-
case _ => (new CheckValidMacroBody).apply(tree)
67+
case _ =>
68+
def checkValidStat(tree: Tree): Unit = tree match {
69+
case tree: ValDef if tree.symbol.is(Synthetic) =>
70+
// Check val from `foo(j = x, i = y)` which it is expanded to
71+
// `val j$1 = x; val i$1 = y; foo(i = y, j = x)`
72+
checkIfValidArgument(tree.rhs)
73+
case _ =>
74+
ctx.error("Macro should not have statements", tree.sourcePos)
75+
}
76+
def checkIfValidArgument(tree: Tree): Unit = tree match {
77+
case Block(Nil, expr) => checkIfValidArgument(expr)
78+
case Typed(expr, _) => checkIfValidArgument(expr)
79+
80+
case Apply(TypeApply(fn, _), quoted :: Nil) if fn.symbol == defn.InternalQuoted_exprQuote =>
81+
// OK
82+
83+
case TypeApply(fn, quoted :: Nil) if fn.symbol == defn.InternalQuoted_typeQuote =>
84+
// OK
85+
86+
case Literal(Constant(value)) =>
87+
// OK
88+
89+
case _ if tree.symbol == defn.QuoteContext_macroContext =>
90+
// OK
91+
92+
case Call(fn, args)
93+
if (fn.symbol.isConstructor && fn.symbol.owner.owner.is(Package)) ||
94+
fn.symbol.is(Module) || fn.symbol.isStatic ||
95+
(fn.qualifier.symbol.is(Module) && fn.qualifier.symbol.isStatic) =>
96+
args.foreach(checkIfValidArgument)
97+
98+
case NamedArg(_, arg) =>
99+
checkIfValidArgument(arg)
100+
101+
case SeqLiteral(elems, _) =>
102+
elems.foreach(checkIfValidArgument)
103+
104+
case tree: Ident if tree.symbol.is(Inline) || tree.symbol.is(Synthetic) =>
105+
// OK
106+
107+
case _ =>
108+
ctx.error(
109+
"""Malformed macro parameter
110+
|
111+
|Parameters may be:
112+
| * Quoted parameters or fields
113+
| * References to inline parameters
114+
| * Literal values of primitive types
115+
|""".stripMargin, tree.sourcePos)
116+
}
117+
def checkIfValidStaticCall(tree: Tree): Unit = tree match {
118+
case Block(stats, expr) =>
119+
stats.foreach(checkValidStat)
120+
checkIfValidStaticCall(expr)
121+
122+
case Typed(expr, _) => checkIfValidStaticCall(expr)
123+
case Call(fn, args)
124+
if (fn.symbol.isConstructor && fn.symbol.owner.owner.is(Package)) ||
125+
fn.symbol.is(Module) || fn.symbol.isStatic ||
126+
(fn.qualifier.symbol.is(Module) && fn.qualifier.symbol.isStatic) =>
127+
args.foreach(checkIfValidArgument)
128+
case _ =>
129+
ctx.error(
130+
"""Malformed macro.
131+
|
132+
|Expected the splice ${...} to contain a single call to a static method.
133+
|""".stripMargin, tree.sourcePos)
134+
}
135+
136+
checkIfValidStaticCall(tree)
68137
}
69138

70139
/** Tree interpreter that evaluates the tree */
71-
private class Interpreter(pos: SourcePosition, classLoader: ClassLoader)(implicit ctx: Context) extends AbstractInterpreter {
140+
private class Interpreter(pos: SourcePosition, classLoader: ClassLoader)(implicit ctx: Context) {
72141

73-
def checking: Boolean = false
74-
75-
type Result = Object
142+
type Env = Map[Name, Object]
76143

77144
/** Returns the interpreted result of interpreting the code a call to the symbol with default arguments.
78145
* Return Some of the result or None if some error happen during the interpretation.
@@ -93,6 +160,76 @@ object Splicer {
93160
}
94161
}
95162

163+
protected final def interpretTree(tree: Tree)(implicit env: Env): Object = tree match {
164+
case Apply(TypeApply(fn, _), quoted :: Nil) if fn.symbol == defn.InternalQuoted_exprQuote =>
165+
val quoted1 = quoted match {
166+
case quoted: Ident if quoted.symbol.isAllOf(InlineByNameProxy) =>
167+
// inline proxy for by-name parameter
168+
quoted.symbol.defTree.asInstanceOf[DefDef].rhs
169+
case Inlined(EmptyTree, _, quoted) => quoted
170+
case _ => quoted
171+
}
172+
interpretQuote(quoted1)
173+
174+
case TypeApply(fn, quoted :: Nil) if fn.symbol == defn.InternalQuoted_typeQuote =>
175+
interpretTypeQuote(quoted)
176+
177+
case Literal(Constant(value)) =>
178+
interpretLiteral(value)
179+
180+
case _ if tree.symbol == defn.QuoteContext_macroContext =>
181+
interpretQuoteContext()
182+
183+
// TODO disallow interpreted method calls as arguments
184+
case Call(fn, args) =>
185+
if (fn.symbol.isConstructor && fn.symbol.owner.owner.is(Package)) {
186+
interpretNew(fn.symbol, args.map(interpretTree))
187+
} else if (fn.symbol.is(Module)) {
188+
interpretModuleAccess(fn.symbol)
189+
} else if (fn.symbol.isStatic) {
190+
val module = fn.symbol.owner
191+
interpretStaticMethodCall(module, fn.symbol, args.map(arg => interpretTree(arg)))
192+
} else if (fn.qualifier.symbol.is(Module) && fn.qualifier.symbol.isStatic) {
193+
val module = fn.qualifier.symbol.moduleClass
194+
interpretStaticMethodCall(module, fn.symbol, args.map(arg => interpretTree(arg)))
195+
} else if (env.contains(fn.name)) {
196+
env(fn.name)
197+
} else if (tree.symbol.is(InlineProxy)) {
198+
interpretTree(tree.symbol.defTree.asInstanceOf[ValOrDefDef].rhs)
199+
} else {
200+
unexpectedTree(tree)
201+
}
202+
203+
// Interpret `foo(j = x, i = y)` which it is expanded to
204+
// `val j$1 = x; val i$1 = y; foo(i = y, j = x)`
205+
case Block(stats, expr) => interpretBlock(stats, expr)
206+
case NamedArg(_, arg) => interpretTree(arg)
207+
208+
case Inlined(_, bindings, expansion) => interpretBlock(bindings, expansion)
209+
210+
case Typed(expr, _) =>
211+
interpretTree(expr)
212+
213+
case SeqLiteral(elems, _) =>
214+
interpretVarargs(elems.map(e => interpretTree(e)))
215+
216+
case _ =>
217+
unexpectedTree(tree)
218+
}
219+
220+
private def interpretBlock(stats: List[Tree], expr: Tree)(implicit env: Env) = {
221+
var unexpected: Option[Object] = None
222+
val newEnv = stats.foldLeft(env)((accEnv, stat) => stat match {
223+
case stat: ValDef =>
224+
accEnv.updated(stat.name, interpretTree(stat.rhs)(accEnv))
225+
case stat =>
226+
if (unexpected.isEmpty)
227+
unexpected = Some(unexpectedTree(stat))
228+
accEnv
229+
})
230+
unexpected.getOrElse(interpretTree(expr)(newEnv))
231+
}
232+
96233
protected def interpretQuote(tree: Tree)(implicit env: Env): Object =
97234
new scala.internal.quoted.TastyTreeExpr(Inlined(EmptyTree, Nil, tree).withSpan(tree.span))
98235

@@ -131,7 +268,7 @@ object Splicer {
131268
protected def interpretModuleAccess(fn: Symbol)(implicit env: Env): Object =
132269
loadModule(fn.moduleClass)
133270

134-
protected def interpretNew(fn: Symbol, args: => List[Result])(implicit env: Env): Object = {
271+
protected def interpretNew(fn: Symbol, args: => List[Object])(implicit env: Env): Object = {
135272
val clazz = loadClass(fn.owner.fullName.toString)
136273
val constr = clazz.getConstructor(paramsSig(fn): _*)
137274
constr.newInstance(args: _*).asInstanceOf[Object]
@@ -265,137 +402,14 @@ object Splicer {
265402

266403
}
267404

268-
/** Tree interpreter that tests if tree can be interpreted */
269-
private class CheckValidMacroBody(implicit ctx: Context) extends AbstractInterpreter {
270-
def checking: Boolean = true
271-
272-
type Result = Unit
273-
274-
def apply(tree: Tree): Unit = interpretTree(tree)(Map.empty)
275-
276-
protected def interpretQuote(tree: tpd.Tree)(implicit env: Env): Unit = ()
277-
protected def interpretTypeQuote(tree: tpd.Tree)(implicit env: Env): Unit = ()
278-
protected def interpretLiteral(value: Any)(implicit env: Env): Unit = ()
279-
protected def interpretVarargs(args: List[Unit])(implicit env: Env): Unit = ()
280-
protected def interpretQuoteContext()(implicit env: Env): Unit = ()
281-
protected def interpretStaticMethodCall(module: Symbol, fn: Symbol, args: => List[Unit])(implicit env: Env): Unit = args.foreach(identity)
282-
protected def interpretModuleAccess(fn: Symbol)(implicit env: Env): Unit = ()
283-
protected def interpretNew(fn: Symbol, args: => List[Unit])(implicit env: Env): Unit = args.foreach(identity)
284-
285-
def unexpectedTree(tree: tpd.Tree)(implicit env: Env): Unit = {
286-
// Assuming that top-level splices can only be in inline methods
287-
// and splices are expanded at inline site, references to inline values
288-
// will be known literal constant trees.
289-
if (!tree.symbol.is(Inline))
290-
ctx.error(
291-
"""Malformed macro.
292-
|
293-
|Expected the splice ${...} to contain a single call to a static method.
294-
|
295-
|Where parameters may be:
296-
| * Quoted paramers or fields
297-
| * References to inline parameters
298-
| * Literal values of primitive types
299-
""".stripMargin, tree.sourcePos)
300-
}
301-
}
302-
303-
/** Abstract Tree interpreter that can interpret calls to static methods with quoted or inline arguments */
304-
private abstract class AbstractInterpreter(implicit ctx: Context) {
305-
306-
def checking: Boolean
307-
308-
type Env = Map[Name, Result]
309-
type Result
310-
311-
protected def interpretQuote(tree: Tree)(implicit env: Env): Result
312-
protected def interpretTypeQuote(tree: Tree)(implicit env: Env): Result
313-
protected def interpretLiteral(value: Any)(implicit env: Env): Result
314-
protected def interpretVarargs(args: List[Result])(implicit env: Env): Result
315-
protected def interpretQuoteContext()(implicit env: Env): Result
316-
protected def interpretStaticMethodCall(module: Symbol, fn: Symbol, args: => List[Result])(implicit env: Env): Result
317-
protected def interpretModuleAccess(fn: Symbol)(implicit env: Env): Result
318-
protected def interpretNew(fn: Symbol, args: => List[Result])(implicit env: Env): Result
319-
protected def unexpectedTree(tree: Tree)(implicit env: Env): Result
320-
321-
protected final def interpretTree(tree: Tree)(implicit env: Env): Result = tree match {
322-
case Apply(TypeApply(fn, _), quoted :: Nil) if fn.symbol == defn.InternalQuoted_exprQuote =>
323-
val quoted1 = quoted match {
324-
case quoted: Ident if quoted.symbol.isAllOf(InlineByNameProxy) =>
325-
// inline proxy for by-name parameter
326-
quoted.symbol.defTree.asInstanceOf[DefDef].rhs
327-
case Inlined(EmptyTree, _, quoted) => quoted
328-
case _ => quoted
329-
}
330-
interpretQuote(quoted1)
331-
332-
case TypeApply(fn, quoted :: Nil) if fn.symbol == defn.InternalQuoted_typeQuote =>
333-
interpretTypeQuote(quoted)
334-
335-
case Literal(Constant(value)) =>
336-
interpretLiteral(value)
337-
338-
case _ if tree.symbol == defn.QuoteContext_macroContext =>
339-
interpretQuoteContext()
340-
341-
case Call(fn, args) =>
342-
if (fn.symbol.isConstructor && fn.symbol.owner.owner.is(Package)) {
343-
interpretNew(fn.symbol, args.map(interpretTree))
344-
} else if (fn.symbol.is(Module)) {
345-
interpretModuleAccess(fn.symbol)
346-
} else if (fn.symbol.isStatic) {
347-
val module = fn.symbol.owner
348-
interpretStaticMethodCall(module, fn.symbol, args.map(arg => interpretTree(arg)))
349-
} else if (fn.qualifier.symbol.is(Module) && fn.qualifier.symbol.isStatic) {
350-
val module = fn.qualifier.symbol.moduleClass
351-
interpretStaticMethodCall(module, fn.symbol, args.map(arg => interpretTree(arg)))
352-
} else if (env.contains(fn.name)) {
353-
env(fn.name)
354-
} else if (tree.symbol.is(InlineProxy)) {
355-
interpretTree(tree.symbol.defTree.asInstanceOf[ValOrDefDef].rhs)
356-
} else {
357-
unexpectedTree(tree)
358-
}
359-
360-
// Interpret `foo(j = x, i = y)` which it is expanded to
361-
// `val j$1 = x; val i$1 = y; foo(i = y, j = x)`
362-
case Block(stats, expr) => interpretBlock(stats, expr)
363-
case NamedArg(_, arg) => interpretTree(arg)
364-
365-
case Inlined(_, bindings, expansion) => interpretBlock(bindings, expansion)
366-
367-
case Typed(expr, _) =>
368-
interpretTree(expr)
369-
370-
case SeqLiteral(elems, _) =>
371-
interpretVarargs(elems.map(e => interpretTree(e)))
372-
373-
case _ =>
374-
unexpectedTree(tree)
375-
}
376-
377-
private def interpretBlock(stats: List[Tree], expr: Tree)(implicit env: Env) = {
378-
var unexpected: Option[Result] = None
379-
val newEnv = stats.foldLeft(env)((accEnv, stat) => stat match {
380-
case stat: ValDef if stat.symbol.is(Synthetic) || !checking =>
381-
accEnv.updated(stat.name, interpretTree(stat.rhs)(accEnv))
382-
case stat =>
383-
if (unexpected.isEmpty)
384-
unexpected = Some(unexpectedTree(stat))
385-
accEnv
386-
})
387-
unexpected.getOrElse(interpretTree(expr)(newEnv))
388-
}
389-
390-
object Call {
391-
def unapply(arg: Tree): Option[(RefTree, List[Tree])] = arg match {
392-
case Select(Call(fn, args), nme.apply) if defn.isImplicitFunctionType(fn.tpe.widenDealias.finalResultType) =>
393-
Some((fn, args))
394-
case fn: RefTree => Some((fn, Nil))
395-
case Apply(Call(fn, args1), args2) => Some((fn, args1 ::: args2)) // TODO improve performance
396-
case TypeApply(Call(fn, args), _) => Some((fn, args))
397-
case _ => None
398-
}
405+
object Call {
406+
def unapply(arg: Tree)(implicit ctx: Context): Option[(RefTree, List[Tree])] = arg match {
407+
case Select(Call(fn, args), nme.apply) if defn.isImplicitFunctionType(fn.tpe.widenDealias.finalResultType) =>
408+
Some((fn, args))
409+
case fn: RefTree => Some((fn, Nil))
410+
case Apply(Call(fn, args1), args2) => Some((fn, args1 ::: args2)) // TODO improve performance
411+
case TypeApply(Call(fn, args), _) => Some((fn, args))
412+
case _ => None
399413
}
400414
}
401415

‎tests/neg-macros/quote-complex-top-splice.scala

Lines changed: 14 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -6,18 +6,22 @@ object Test {
66

77
inline def foo1: Unit = ${
88
val x = 1 // error
9-
impl(x)
9+
impl(x) // error
1010
}
1111

12-
inline def foo2: Unit = ${ impl({
13-
val x = 1 // error
14-
x
15-
}) }
16-
17-
inline def foo3: Unit = ${ impl({
18-
println("foo3") // error
19-
3
20-
}) }
12+
inline def foo2: Unit = ${ impl(
13+
{ // error
14+
val x = 1
15+
x
16+
}
17+
) }
18+
19+
inline def foo3: Unit = ${ impl(
20+
{ // error
21+
println("foo3")
22+
3
23+
}
24+
) }
2125

2226
inline def foo4: Unit = ${
2327
println("foo4") // error

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