try the approach we use for vars

jamieQ · jamieQ · commit 0df8c6315d82 · 2025-10-19T16:48:06.000-05:00
diff --git a/lib/SILGen/SILGenDecl.cpp b/lib/SILGen/SILGenDecl.cpp
@@ -40,8 +40,6 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <iterator>
 
-#define DEBUG_TYPE "SILGenDecl"
-
 using namespace swift;
 using namespace Lowering;
 
@@ -810,12 +808,6 @@ class LetValueInitialization : public Initialization {
               lowering->getLoweredType().isMoveOnly(/*orWrapped=*/false);
     }
 
-//    auto parentInit = vd->getParentInitializer();
-//    if (isa<CallExpr>(parentInit)) {
-//      auto fn = cast<CallExpr>(parentInit)->getSemanticFn();
-//      isUninitialized = isa<AbstractClosureExpr>(fn);
-//    }
-
     // Make sure that we have a non-address only type when binding a
     // @_noImplicitCopy let.
     if (lowering->isAddressOnly() && vd->isNoImplicitCopy()) {
@@ -824,10 +816,6 @@ class LetValueInitialization : public Initialization {
     }
 
     if (needsTemporaryBuffer) {
-      LLVM_DEBUG({
-        llvm::dbgs() << "JQ: need tmp buffer\n";
-        vd->dump(llvm::dbgs());
-      });
       bool lexicalLifetimesEnabled =
           SGF.getASTContext().SILOpts.supportsLexicalLifetimes(SGF.getModule());
       auto lifetime = SGF.F.getLifetime(vd, lowering->getLoweredType());
@@ -837,14 +825,13 @@ class LetValueInitialization : public Initialization {
                                             DoesNotHaveDynamicLifetime,
                                             isLexical, IsFromVarDecl);
 
-      // Ensure DI always checks this to avoid cases where an address-only
-      // value is referenced in a closure that is part of its initializer.
-      if (true || isUninitialized)
+      if (isUninitialized)
         address = SGF.B.createMarkUninitializedVar(vd, address);
 
       DestroyCleanup = SGF.enterDormantTemporaryCleanup(address, *lowering);
-      SGF.VarLocs[vd] = SILGenFunction::VarLoc(address,
-                                               SILAccessEnforcement::Unknown);
+
+      // We do not register the address in VarLocs yet so that the capture-
+      // before-definition machinery will diagnose these cases.
     }
     // Push a cleanup to destroy the let declaration.  This has to be
     // inactive until the variable is initialized: if control flow exits the
@@ -1022,7 +1009,16 @@ class LetValueInitialization : public Initialization {
   void finishInitialization(SILGenFunction &SGF) override {
     assert(!DidFinish &&
            "called LetValueInit::finishInitialization twice!");
-    assert(SGF.VarLocs.count(vd) && "Didn't bind a value to this let!");
+
+    if (!address) {
+      // We should have already in the non-address case.
+      assert(SGF.VarLocs.count(vd) && "Didn't bind a value to this let!");
+    } else {
+      // We delayed the emission to catch forward declaration uses.
+      assert(SGF.VarLocs.count(vd) == 0 && "Should not have emitted the address-only let!");
+      SGF.VarLocs[vd] = SILGenFunction::VarLoc(address,
+                                               SILAccessEnforcement::Unknown);
+    }
 
     // Deactivate any cleanups we made when splitting the tuple.
     for (auto cleanup : SplitCleanups)
diff --git a/lib/SILGen/SILGenFunction.cpp b/lib/SILGen/SILGenFunction.cpp
@@ -590,16 +590,6 @@ void SILGenFunction::emitCaptures(SILLocation loc,
     break;
   }
 
-  LLVM_DEBUG({
-    llvm::dbgs() << "JQ: emit captures running\n";
-    for (auto capture : captureInfo.getCaptures()) {
-      llvm::dbgs() << "  cap: '" << capture.getDecl()->getName() << "'\n";
-    }
-    llvm::dbgs()
-      << "  canGuarantee: '" << canGuarantee << "'\n"
-      << "  capCanEscape: '" << captureCanEscape << "'\n";
-  });
-
   auto expansion = getTypeExpansionContext();
 
   for (auto capture : captureInfo.getCaptures()) {
@@ -619,7 +609,6 @@ void SILGenFunction::emitCaptures(SILLocation loc,
     if (capture.isOpaqueValue() || capture.isPackElement()) {
       capturedArgs.push_back(
           emitRValueAsSingleValue(capture.getExpr()).ensurePlusOne(*this, loc));
-      LLVM_DEBUG(llvm::dbgs() << "JQ: cap emit early ret: opaque || pack\n");
       continue;
     }
 
@@ -643,52 +632,6 @@ void SILGenFunction::emitCaptures(SILLocation loc,
     auto valueType = FunctionDC->mapTypeIntoContext(
       interfaceType->getReferenceStorageReferent());
 
-    LLVM_DEBUG(
-    {
-      llvm::dbgs() << "=== DEBUG: VarLocs contents for capture of '"
-      << vd->getBaseIdentifier() << "' ===\n";
-      llvm::dbgs() << "Total entries in VarLocs: " << VarLocs.size() << "\n";
-
-      for (auto &entry : VarLocs) {
-        auto *var = entry.first;
-        auto &loc = entry.second;
-
-        llvm::dbgs() << "  - Variable: " << var->getBaseIdentifier() << "\n";
-        //      llvm::errs() << "    Type: " << var->getType() << "\n";
-        llvm::dbgs() << "    Value type: " << loc.value->getType() << "\n";
-        llvm::dbgs() << "    Value kind: ";
-
-        if (isa<SILUndef>(loc.value)) {
-          llvm::dbgs() << "SILUndef (UNINITIALIZED)\n";
-        } else if (isa<SILArgument>(loc.value)) {
-          llvm::dbgs() << "SILArgument\n";
-        } else if (isa<AllocStackInst>(loc.value)) {
-          llvm::dbgs() << "AllocStackInst\n";
-        } else if (isa<AllocBoxInst>(loc.value)) {
-          llvm::dbgs() << "AllocBoxInst\n";
-        } else {
-          llvm::dbgs() << "some other inst\n";
-        }
-
-        if (loc.box) {
-          llvm::dbgs() << "    Has box: yes\n";
-        }
-
-        llvm::dbgs() << "\n";
-      }
-
-      llvm::dbgs() << "Looking for variable: " << vd->getBaseIdentifier() << "\n";
-      auto found = VarLocs.find(vd);
-      if (found == VarLocs.end()) {
-        llvm::dbgs() << "  Result: NOT FOUND in VarLocs\n";
-      } else {
-        llvm::dbgs() << "  Result: FOUND in VarLocs\n";
-        llvm::dbgs() << "  Value is undef: "
-        << (isa<SILUndef>(found->second.value) ? "YES" : "NO") << "\n";
-      }
-      llvm::dbgs() << "===================================\n\n";
-    });
-
     //
     // If we haven't emitted the captured value yet, we're forming a closure
     // to a local function before all of its captures have been emitted. Eg,
@@ -752,12 +695,6 @@ void SILGenFunction::emitCaptures(SILLocation loc,
     // expansion context without opaque archetype substitution.
     auto getAddressValue = [&](SILValue entryValue, bool forceCopy,
                                bool forLValue) -> SILValue {
-      LLVM_DEBUG({
-        llvm::dbgs() << "JQ: get addr value, force copy: " << forceCopy
-          << ", for lval: " << forLValue << "\n";
-        entryValue->getDefiningInstruction()->print(llvm::dbgs());
-      });
-
       if (!SGM.M.useLoweredAddresses() && !forLValue && !isPack) {
         // In opaque values mode, addresses aren't used except by lvalues.
         auto &lowering = getTypeLowering(entryValue->getType());
@@ -838,11 +775,6 @@ void SILGenFunction::emitCaptures(SILLocation loc,
     auto &Entry = found->second;
     auto val = Entry.value;
 
-    LLVM_DEBUG({
-      auto capKind = SGM.Types.getDeclCaptureKind(capture, expansion);
-      llvm::dbgs() << "JQ: cap kind:: " << (unsigned)capKind << "\n";
-    });
-
     switch (SGM.Types.getDeclCaptureKind(capture, expansion)) {
     case CaptureKind::Constant: {
       assert(!isPack);
@@ -923,12 +855,6 @@ void SILGenFunction::emitCaptures(SILLocation loc,
         }
         capturedArgs.push_back(ManagedValue::forOwnedAddressRValue(
             addr, CleanupHandle::invalid()));
-
-//        LLVM_DEBUG({
-//          llvm::dbgs() << "JQ: adding escape to mark for: \n";
-//          val->getDefiningInstruction()->print(llvm::dbgs());
-//        });
-//        escapesToMark.push_back(val);
       }
       break;
     }
diff --git a/lib/SILOptimizer/Mandatory/DIMemoryUseCollector.cpp b/lib/SILOptimizer/Mandatory/DIMemoryUseCollector.cpp
@@ -823,27 +823,6 @@ void ElementUseCollector::collectUses(SILValue Pointer, unsigned BaseEltNo) {
       continue;
     }
 
-    if (false || (isa<UnconditionalCheckedCastAddrInst>(User) ||
-                  isa<CheckedCastAddrBranchInst>(User))) {
-      LLVM_DEBUG({
-        llvm::dbgs() << "JQ: DI found unchecked addr cast:\n"
-        << Op;
-      });
-
-      DIUseKind Kind;
-      Kind = DIUseKind::Initialization;
-//      if (Op->getOperandNumber() == 0)
-//        Kind = DIUseKind::Load;
-//      else
-//        Kind = InStructSubElement ? DIUseKind::PartialStore
-//                                  : DIUseKind::Initialization;
-
-      // TODO: what about enum sub elt? do we need to even special case things here?
-
-      addElementUses(BaseEltNo, PointeeType, User, Kind);
-      continue;
-    }
-
     // Look through mark_unresolved_non_copyable_value. To us, it is not
     // interesting.
     if (auto *mmi = dyn_cast<MarkUnresolvedNonCopyableValueInst>(User)) {
diff --git a/test/SILGen/capture_order.swift b/test/SILGen/capture_order.swift
@@ -192,3 +192,19 @@ func func77933460() {
   // expected-note@-3 {{captured value declared here}}
   // expected-warning@-4 {{variable 'obj' was never mutated; consider changing to 'let' constant}}
 }
+
+// MARK: -
+
+func address_only_lets() {
+  let bad1 = { () -> Any in bad1 }()
+  // expected-error@-1 {{closure captures 'bad1' before it is declared}}
+  // expected-note@-2 {{captured here}}
+  // expected-note@-3 {{captured value declared here}}
+
+
+  func indirect(_ i: () -> Any) -> Any { i() }
+  let bad2 = indirect { bad2 }
+  // expected-error@-1 {{closure captures 'bad2' before it is declared}}
+  // expected-note@-2 {{captured here}}
+  // expected-note@-3 {{captured value declared here}}
+}
diff --git a/test/SILGen/consume_operator.swift b/test/SILGen/consume_operator.swift
@@ -42,10 +42,9 @@ func testLoadableVar() {
 
 // CHECK-LABEL: sil hidden [ossa] @$s7consume18testAddressOnlyLetyyxmAA1PRzlF : $@convention(thin) <T where T : P> (@thick T.Type) -> () {
 // CHECK: [[BOX:%.*]] = alloc_stack [lexical] [var_decl] $T
-// CHECK: [[MUI:%.*]] = mark_uninitialized [var] [[BOX]]
 //
 // CHECK: [[STACK:%.*]] = alloc_stack $T
-// CHECK: mark_unresolved_move_addr [[MUI]] to [[STACK]]
+// CHECK: mark_unresolved_move_addr [[BOX]] to [[STACK]]
 //
 // CHECK: } // end sil function '$s7consume18testAddressOnlyLetyyxmAA1PRzlF'
 func testAddressOnlyLet<T : P>(_ t: T.Type) {
