[ConstraintSystem] NFC: Move salvage from CSDiag to ConstraintSystem

Author: xedin

lib/Sema/CSDiag.cpp

@@ -9069,86 +9069,6 @@ ValueDecl *ConstraintSystem::findResolvedMemberRef(ConstraintLocator *locator) {
   return nullptr;
 }
 
-
-bool ConstraintSystem::salvage(SmallVectorImpl<Solution> &viable, Expr *expr) {
-  if (TC.getLangOpts().DebugConstraintSolver) {
-    auto &log = TC.Context.TypeCheckerDebug->getStream();
-    log << "---Attempting to salvage and emit diagnostics---\n";
-  }
-
-  // Attempt to solve again, capturing all states that come from our attempts to
-  // select overloads or bind type variables.
-  //
-  // FIXME: can this be removed?  We need to arrange for recordFixes to be
-  // eliminated.
-  viable.clear();
-
-  {
-    // Set up solver state.
-    SolverState state(expr, *this);
-    state.recordFixes = true;
-
-    // Solve the system.
-    solveRec(viable, FreeTypeVariableBinding::Disallow);
-
-    // Check whether we have a best solution; this can happen if we found
-    // a series of fixes that worked.
-    if (auto best = findBestSolution(viable, state.ExprWeights,
-                                     /*minimize=*/true)) {
-      if (*best != 0)
-        viable[0] = std::move(viable[*best]);
-      viable.erase(viable.begin() + 1, viable.end());
-      return false;
-    }
-
-    // FIXME: If we were able to actually fix things along the way,
-    // we may have to hunt for the best solution. For now, we don't care.
-
-    // Before removing any "fixed" solutions, let's check
-    // if ambiguity is caused by fixes and diagnose if possible.
-    if (diagnoseAmbiguityWithFixes(expr, viable))
-      return true;
-
-    // Remove solutions that require fixes; the fixes in those systems should
-    // be diagnosed rather than any ambiguity.
-    auto hasFixes = [](const Solution &sol) { return !sol.Fixes.empty(); };
-    auto newEnd = std::remove_if(viable.begin(), viable.end(), hasFixes);
-    viable.erase(newEnd, viable.end());
-
-    // If there are multiple solutions, try to diagnose an ambiguity.
-    if (viable.size() > 1) {
-      if (getASTContext().LangOpts.DebugConstraintSolver) {
-        auto &log = getASTContext().TypeCheckerDebug->getStream();
-        log << "---Ambiguity error: "
-            << viable.size() << " solutions found---\n";
-        int i = 0;
-        for (auto &solution : viable) {
-          log << "---Ambiguous solution #" << i++ << "---\n";
-          solution.dump(log);
-          log << "\n";
-        }
-      }
-
-      if (diagnoseAmbiguity(expr, viable)) {
-        return true;
-      }
-    }
-
-    // Fall through to produce diagnostics.
-  }
-
-  if (getExpressionTooComplex(viable)) {
-    TC.diagnose(expr->getLoc(), diag::expression_too_complex).
-    highlight(expr->getSourceRange());
-    return true;
-  }
-
-  // If all else fails, diagnose the failure by looking through the system's
-  // constraints.
-  diagnoseFailureForExpr(expr);
-  return true;
-}
-
 bool swift::diagnoseBaseUnwrapForMemberAccess(Expr *baseExpr, Type baseType,
                                               DeclName memberName,
                                               bool resultOptional,

lib/Sema/ConstraintSystem.cpp

@@ -2082,3 +2082,82 @@ bool OverloadChoice::isImplicitlyUnwrappedValueOrReturnValue() const {
     return true;
   }
 }
+
+bool ConstraintSystem::salvage(SmallVectorImpl<Solution> &viable, Expr *expr) {
+  if (TC.getLangOpts().DebugConstraintSolver) {
+    auto &log = TC.Context.TypeCheckerDebug->getStream();
+    log << "---Attempting to salvage and emit diagnostics---\n";
+  }
+
+  // Attempt to solve again, capturing all states that come from our attempts to
+  // select overloads or bind type variables.
+  //
+  // FIXME: can this be removed?  We need to arrange for recordFixes to be
+  // eliminated.
+  viable.clear();
+
+  {
+    // Set up solver state.
+    SolverState state(expr, *this);
+    state.recordFixes = true;
+
+    // Solve the system.
+    solveRec(viable, FreeTypeVariableBinding::Disallow);
+
+    // Check whether we have a best solution; this can happen if we found
+    // a series of fixes that worked.
+    if (auto best = findBestSolution(viable, state.ExprWeights,
+                                     /*minimize=*/true)) {
+      if (*best != 0)
+        viable[0] = std::move(viable[*best]);
+      viable.erase(viable.begin() + 1, viable.end());
+      return false;
+    }
+
+    // FIXME: If we were able to actually fix things along the way,
+    // we may have to hunt for the best solution. For now, we don't care.
+
+    // Before removing any "fixed" solutions, let's check
+    // if ambiguity is caused by fixes and diagnose if possible.
+    if (diagnoseAmbiguityWithFixes(expr, viable))
+      return true;
+
+    // Remove solutions that require fixes; the fixes in those systems should
+    // be diagnosed rather than any ambiguity.
+    auto hasFixes = [](const Solution &sol) { return !sol.Fixes.empty(); };
+    auto newEnd = std::remove_if(viable.begin(), viable.end(), hasFixes);
+    viable.erase(newEnd, viable.end());
+
+    // If there are multiple solutions, try to diagnose an ambiguity.
+    if (viable.size() > 1) {
+      if (getASTContext().LangOpts.DebugConstraintSolver) {
+        auto &log = getASTContext().TypeCheckerDebug->getStream();
+        log << "---Ambiguity error: " << viable.size()
+            << " solutions found---\n";
+        int i = 0;
+        for (auto &solution : viable) {
+          log << "---Ambiguous solution #" << i++ << "---\n";
+          solution.dump(log);
+          log << "\n";
+        }
+      }
+
+      if (diagnoseAmbiguity(expr, viable)) {
+        return true;
+      }
+    }
+
+    // Fall through to produce diagnostics.
+  }
+
+  if (getExpressionTooComplex(viable)) {
+    TC.diagnose(expr->getLoc(), diag::expression_too_complex)
+        .highlight(expr->getSourceRange());
+    return true;
+  }
+
+  // If all else fails, diagnose the failure by looking through the system's
+  // constraints.
+  diagnoseFailureForExpr(expr);
+  return true;
+}