Merge pull request #59856 from amritpan/improve-disjunction-printing

[ConstraintSystem] Improve initial constraints printing in the type inference algorithm debug output

Author: xedin

include/swift/Sema/Constraint.h

@@ -852,7 +852,10 @@ class Constraint final : public llvm::ilist_node<Constraint>,
   /// Clone the given constraint.
   Constraint *clone(ConstraintSystem &cs) const;
 
-  void print(llvm::raw_ostream &Out, SourceManager *sm) const;
+  /// Print constraint placed on type and constraint properties.
+  ///
+  /// \c skipLocator skips printing of locators.
+  void print(llvm::raw_ostream &Out, SourceManager *sm, bool skipLocator = false) const;
 
   SWIFT_DEBUG_DUMPER(dump(SourceManager *SM));
 

lib/Sema/Constraint.cpp

@@ -322,7 +322,7 @@ Constraint *Constraint::clone(ConstraintSystem &cs) const {
   llvm_unreachable("Unhandled ConstraintKind in switch.");
 }
 
-void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm) const {
+void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm, bool skipLocator) const {
   // Print all type variables as $T0 instead of _ here.
   PrintOptions PO;
   PO.PrintTypesForDebugging = true;
@@ -343,16 +343,30 @@ void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm) const {
       Out << "]]";
     }
     Out << ":\n";
-
-    interleave(getNestedConstraints(),
+    
+    // Sort constraints by favored, unmarked, disabled
+    // for printing only.
+    std::vector<Constraint *> sortedConstraints(getNestedConstraints().begin(),
+                                                getNestedConstraints().end());
+    llvm::sort(sortedConstraints,
+               [](const Constraint *lhs, const Constraint *rhs) {
+                 if (lhs->isFavored() != rhs->isFavored())
+                   return lhs->isFavored();
+                 if (lhs->isDisabled() != rhs->isDisabled())
+                   return rhs->isDisabled();
+                 return false;
+               });
+
+    interleave(sortedConstraints,
                [&](Constraint *constraint) {
                  if (constraint->isDisabled())
                    Out << ">  [disabled] ";
                  else if (constraint->isFavored())
                    Out << ">  [favored]  ";
                  else
                    Out << ">             ";
-                 constraint->print(Out, sm);
+                 constraint->print(Out, sm,
+                   /*skipLocator=*/constraint->getLocator() == Locator);
                },
                [&] { Out << "\n"; });
     return;
@@ -522,7 +536,7 @@ void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm) const {
     fix->print(Out);
   }
 
-  if (Locator) {
+  if (Locator && !skipLocator) {
     Out << " [[";
     Locator->dump(sm, Out);
     Out << "]];";

test/Constraints/overload_filtering_objc.swift

@@ -25,10 +25,10 @@ func testOptional(obj: P) {
 
 
 func test_double_cgfloat_conversion_filtering(d: Double, cgf: CGFloat) {
-  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).CGFloat.init(_:)@{{.*}} : (CGFloat.Type) -> (Double) -> CGFloat {{.*}} -> implicit conversion [Double-to-CGFloat] -> apply function -> constructor member
+  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).CGFloat.init(_:)@{{.*}} : (CGFloat.Type) -> (Double) -> CGFloat
   let _: CGFloat = d
 
-  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).Double extension.init(_:)@{{.*}} : (Double.Type) -> (CGFloat) -> Double {{.*}} -> implicit conversion [CGFloat-to-Double] -> apply function -> constructor member
+  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).Double extension.init(_:)@{{.*}} : (Double.Type) -> (CGFloat) -> Double
   let _: Double = cgf
 
   func test_optional_cgf(_: CGFloat??) {
@@ -37,9 +37,9 @@ func test_double_cgfloat_conversion_filtering(d: Double, cgf: CGFloat) {
   func test_optional_double(_: Double??) {
   }
 
-  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).CGFloat.init(_:)@{{.*}} : (CGFloat.Type) -> (Double) -> CGFloat {{.*}} -> implicit conversion [Double-to-CGFloat] -> apply function -> constructor member
+  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).CGFloat.init(_:)@{{.*}} : (CGFloat.Type) -> (Double) -> CGFloat
   test_optional_cgf(d)
 
-  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).Double extension.init(_:)@{{.*}} : (Double.Type) -> (CGFloat) -> Double {{.*}} -> implicit conversion [CGFloat-to-Double] -> apply function -> constructor member
+  // CHECK: [favored] $T{{.*}} bound to decl CoreGraphics.(file).Double extension.init(_:)@{{.*}} : (Double.Type) -> (CGFloat) -> Double
   test_optional_double(cgf)
 }