[ConstraintSystem] Refactor solver state depth to its own function for easier indent editing in future.

Author: Amritpan Kaur

include/swift/Sema/ConstraintSystem.h

@@ -3053,9 +3053,9 @@ class ConstraintSystem {
     ConstraintSystem &CS;
 
     FreeTypeVariableBinding AllowFreeTypeVariables;
-
-    /// Depth of the solution stack.
-    unsigned depth = 0;
+    
+    /// Return current depth of solution stack for debug printing.
+    unsigned int getCurrentIndent() const { return depth * 2; }
 
     /// Maximum depth reached so far in exploring solutions.
     unsigned maxDepth = 0;
@@ -3238,6 +3238,9 @@ class ConstraintSystem {
 
     SmallVector<Constraint *, 4> disabledConstraints;
     SmallVector<Constraint *, 4> favoredConstraints;
+    
+    /// Depth of the solution stack.
+    unsigned depth = 0;
   };
 
   class CacheExprTypes : public ASTWalker {
@@ -4341,7 +4344,7 @@ class ConstraintSystem {
 
     if (isDebugMode()) {
       auto &log = llvm::errs();
-      log.indent(solverState ? solverState->depth * 2 : 0)
+      log.indent(solverState ? solverState->getCurrentIndent() : 0)
           << "(failed constraint ";
       constraint->print(log, &getASTContext().SourceMgr);
       log << ")\n";

lib/Sema/BuilderTransform.cpp

@@ -2528,7 +2528,7 @@ ConstraintSystem::matchResultBuilder(AnyFunctionRef fn, Type builderType,
 
     if (isDebugMode()) {
       auto &log = llvm::errs();
-      auto indent = solverState ? solverState->depth * 2 : 0;
+      auto indent = solverState ? solverState->getCurrentIndent() : 0;
       log.indent(indent) << "------- Transfomed Body -------\n";
       transformedBody->second->dump(log);
       log << '\n';

lib/Sema/CSBindings.cpp

@@ -808,7 +808,7 @@ Optional<BindingSet> ConstraintSystem::determineBestBindings() {
       continue;
 
     if (isDebugMode()) {
-      bindings.dump(typeVar, llvm::errs(), solverState->depth * 2);
+      bindings.dump(typeVar, llvm::errs(), solverState->getCurrentIndent());
     }
 
     // If these are the first bindings, or they are better than what

lib/Sema/CSRanking.cpp

@@ -54,7 +54,7 @@ void ConstraintSystem::increaseScore(ScoreKind kind, unsigned value) {
 
   if (isDebugMode() && value > 0) {
     if (solverState)
-      llvm::errs().indent(solverState->depth * 2);
+      llvm::errs().indent(solverState->getCurrentIndent());
     llvm::errs() << "(increasing '" << Score::getNameFor(kind) << "' score by "  << value 
                  << ")\n";
   }
@@ -72,7 +72,7 @@ bool ConstraintSystem::worseThanBestSolution() const {
     return false;
 
   if (isDebugMode()) {
-    llvm::errs().indent(solverState->depth * 2)
+    llvm::errs().indent(solverState->getCurrentIndent())
       << "(solution is worse than the best solution)\n";
   }
 
@@ -795,7 +795,7 @@ SolutionCompareResult ConstraintSystem::compareSolutions(
     ConstraintSystem &cs, ArrayRef<Solution> solutions,
     const SolutionDiff &diff, unsigned idx1, unsigned idx2) {
   if (cs.isDebugMode()) {
-    llvm::errs().indent(cs.solverState->depth * 2)
+    llvm::errs().indent(cs.solverState->getCurrentIndent())
       << "comparing solutions " << idx1 << " and " << idx2 <<"\n";
   }
 
@@ -1352,13 +1352,13 @@ ConstraintSystem::findBestSolution(SmallVectorImpl<Solution> &viable,
     return 0;
 
   if (isDebugMode()) {
-    llvm::errs().indent(solverState->depth * 2)
+    llvm::errs().indent(solverState->getCurrentIndent())
         << "Comparing " << viable.size() << " viable solutions\n";
 
     for (unsigned i = 0, n = viable.size(); i != n; ++i) {
-      llvm::errs().indent(solverState->depth * 2)
+      llvm::errs().indent(solverState->getCurrentIndent())
           << "\n--- Solution #" << i << " ---\n";
-      viable[i].dump(llvm::errs().indent(solverState->depth * 2));
+      viable[i].dump(llvm::errs().indent(solverState->getCurrentIndent()));
     }
   }
 

lib/Sema/CSSimplify.cpp

@@ -11187,7 +11187,7 @@ bool ConstraintSystem::simplifyAppliedOverloadsImpl(
     if (isDebugMode()) {
       PrintOptions PO;
       PO.PrintTypesForDebugging = true;
-      llvm::errs().indent(solverState ? solverState->depth * 2 : 0)
+      llvm::errs().indent(solverState ? solverState->getCurrentIndent() : 0)
         << "(common result type for $T" << fnTypeVar->getID() << " is "
         << commonResultType.getString(PO)
         << ")\n";
@@ -12693,7 +12693,7 @@ static bool isAugmentingFix(ConstraintFix *fix) {
 bool ConstraintSystem::recordFix(ConstraintFix *fix, unsigned impact) {
   if (isDebugMode()) {
     auto &log = llvm::errs();
-    log.indent(solverState ? solverState->depth * 2 : 0)
+    log.indent(solverState ? solverState->getCurrentIndent() : 0)
       << "(attempting fix ";
     fix->print(log);
     log << ")\n";

lib/Sema/CSSolver.cpp

@@ -1619,7 +1619,7 @@ ConstraintSystem::filterDisjunction(
     }
 
     if (isDebugMode()) {
-      llvm::errs().indent(solverState ? solverState->depth * 2 : 0)
+      llvm::errs().indent(solverState ? solverState->getCurrentIndent() : 0)
         << "(disabled disjunction term ";
       constraint->print(llvm::errs(), &ctx.SourceMgr);
       llvm::errs() << ")\n";
@@ -1678,7 +1678,7 @@ ConstraintSystem::filterDisjunction(
     }
 
     if (isDebugMode()) {
-      llvm::errs().indent(solverState ? solverState->depth * 2 : 0)
+      llvm::errs().indent(solverState ? solverState->getCurrentIndent(): 0)
         << "(introducing single enabled disjunction term ";
       choice->print(llvm::errs(), &ctx.SourceMgr);
       llvm::errs() << ")\n";

lib/Sema/CSStep.h

@@ -229,7 +229,7 @@ class SolverStep {
 
   llvm::raw_ostream &getDebugLogger(bool indent = true) const {
     auto &log = llvm::errs();
-    return indent ? log.indent(CS.solverState->depth * 2) : log;
+    return indent ? log.indent(CS.solverState->getCurrentIndent()) : log;
   }
 };
 
@@ -519,7 +519,7 @@ template <typename P> class BindingStep : public SolverStep {
       if (CS.isDebugMode()) {
         auto &log = getDebugLogger();
         log << "(attempting ";
-        choice->print(log, &CS.getASTContext().SourceMgr, CS.solverState->depth * 2 + 2);
+        choice->print(log, &CS.getASTContext().SourceMgr, CS.solverState->getCurrentIndent() + 2);
         log << '\n';
       }
 

lib/Sema/ConstraintGraph.cpp

@@ -1135,7 +1135,7 @@ namespace {
             if (cs.isDebugMode()) {
               auto &log = llvm::errs();
               if (cs.solverState)
-                log.indent(cs.solverState->depth * 2);
+                log.indent(cs.solverState->getCurrentIndent());
 
               log << "Collapsing one-way components for $T"
                   << edge.first->getID() << " and $T" << edge.second->getID()
@@ -1440,7 +1440,7 @@ bool ConstraintGraph::contractEdges() {
     if (CS.isDebugMode()) {
       auto &log = llvm::errs();
       if (CS.solverState)
-        log.indent(CS.solverState->depth * 2);
+        log.indent(CS.solverState->getCurrentIndent());
 
       log << "Contracting constraint ";
       constraint->print(log, &CS.getASTContext().SourceMgr);

lib/Sema/ConstraintSystem.cpp

@@ -3528,7 +3528,7 @@ void ConstraintSystem::resolveOverload(ConstraintLocator *locator,
   if (isDebugMode()) {
     PrintOptions PO;
     PO.PrintTypesForDebugging = true;
-    llvm::errs().indent(solverState ? solverState->depth * 2 : 2)
+    llvm::errs().indent(solverState ? solverState->getCurrentIndent() : 2)
       << "(overload set choice binding "
       << boundType->getString(PO) << " := "
       << adjustedRefType->getString(PO) << ")\n";