Properly interpolate negative AP literals

Integer and Floating literals are aware of their negation but
do not store the sign in the text of the value.  Retrieve the
sign bit and properly interpolate the text of the literal value
with it to distinguish negative and positive literals.

Author: CodaFi

include/swift/AST/Expr.h

@@ -893,7 +893,7 @@ class IntegerLiteralExpr : public NumberLiteralExpr {
   {}
 
   APInt getValue() const;
-  static APInt getValue(StringRef Text, unsigned BitWidth);
+  static APInt getValue(StringRef Text, unsigned BitWidth, bool Negative);
 
   static bool classof(const Expr *E) {
     return E->getKind() == ExprKind::IntegerLiteral;
@@ -910,7 +910,8 @@ class FloatLiteralExpr : public NumberLiteralExpr {
   {}
 
   APFloat getValue() const;
-  static APFloat getValue(StringRef Text, const llvm::fltSemantics &Semantics);
+  static APFloat getValue(StringRef Text, const llvm::fltSemantics &Semantics,
+                          bool Negative);
 
   static bool classof(const Expr *E) {
     return E->getKind() == ExprKind::FloatLiteral;

lib/AST/Expr.cpp

@@ -1005,8 +1005,8 @@ static APInt getIntegerLiteralValue(bool IsNegative, StringRef Text,
   return Value;
 }
 
-APInt IntegerLiteralExpr::getValue(StringRef Text, unsigned BitWidth) {
-  return getIntegerLiteralValue(/*IsNegative=*/false, Text, BitWidth);
+APInt IntegerLiteralExpr::getValue(StringRef Text, unsigned BitWidth, bool Negative) {
+  return getIntegerLiteralValue(Negative, Text, BitWidth);
 }
 
 APInt IntegerLiteralExpr::getValue() const {
@@ -1035,8 +1035,9 @@ static APFloat getFloatLiteralValue(bool IsNegative, StringRef Text,
 }
 
 APFloat FloatLiteralExpr::getValue(StringRef Text,
-                                   const llvm::fltSemantics &Semantics) {
-  return getFloatLiteralValue(/*IsNegative*/false, Text, Semantics);
+                                   const llvm::fltSemantics &Semantics,
+                                   bool Negative) {
+  return getFloatLiteralValue(Negative, Text, Semantics);
 }
 
 llvm::APFloat FloatLiteralExpr::getValue() const {

lib/IRGen/GenEnum.cpp

@@ -1027,10 +1027,8 @@ namespace {
       auto intType = getDiscriminatorType();
 
       APInt intValue = IntegerLiteralExpr::getValue(intExpr->getDigitsText(),
-                                                    intType->getBitWidth());
-
-      if (intExpr->isNegative())
-        intValue = -intValue;
+                                                    intType->getBitWidth(),
+                                                    intExpr->isNegative());
 
       return intValue.getZExtValue();
     }

lib/Sema/TypeCheckSwitchStmt.cpp

@@ -980,7 +980,7 @@ namespace {
         auto *ILE = cast<IntegerLiteralExpr>(EL);
         auto cacheVal =
             IntLiteralCache.insert(
-                {ILE->getValue(ILE->getDigitsText(), 128), ILE});
+                {ILE->getValue(ILE->getDigitsText(), 128, ILE->isNegative()), ILE});
         PrevPattern = (cacheVal.first != IntLiteralCache.end())
                     ? cacheVal.first->getSecond()
                     : nullptr;
@@ -993,7 +993,7 @@ namespace {
         auto cacheVal =
             FloatLiteralCache.insert(
                    {FLE->getValue(FLE->getDigitsText(),
-                                  APFloat::IEEEquad()), FLE});
+                                  APFloat::IEEEquad(), FLE->isNegative()), FLE});
         PrevPattern = (cacheVal.first != FloatLiteralCache.end())
                     ? cacheVal.first->getSecond()
                     : nullptr;

test/Sema/exhaustive_switch.swift

@@ -559,8 +559,7 @@ func infinitelySized() -> Bool {
   }
 }
 
-// Literal Duplicate checks
-func checkLiterals() {
+func diagnoseDuplicateLiterals() {
   let str = "def"
   let int = 2
   let dbl = 2.5
@@ -614,13 +613,18 @@ func checkLiterals() {
 
   // No Diagnostics
   switch int {
+  case -2: break
+  case -1: break
+  case 0: break
   case 1: break
   case 2: break
   case 3: break
   default: break
   }
 
   switch int {
+  case -2: break // expected-note {{first occurrence of identical literal pattern is here}}
+  case -2: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
   case 1: break
   case 2: break // expected-note {{first occurrence of identical literal pattern is here}}
   case 2: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
@@ -629,6 +633,7 @@ func checkLiterals() {
   }
 
   switch int {
+  case -2, -2: break // expected-note {{first occurrence of identical literal pattern is here}} expected-warning {{literal value is already handled by previous pattern; consider removing it}}
   case 1, 2: break // expected-note 3 {{first occurrence of identical literal pattern is here}}
   case 2, 3: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
   case 1, 2: break // expected-warning 2 {{literal value is already handled by previous pattern; consider removing it}}
@@ -655,10 +660,12 @@ func checkLiterals() {
   switch int {
   case 10: break
   case 0b10: break // expected-note {{first occurrence of identical literal pattern is here}}
+  case -0b10: break // expected-note {{first occurrence of identical literal pattern is here}}
   case 3000: break
   case 0x12: break // expected-note {{first occurrence of identical literal pattern is here}}
   case 400: break
   case 2: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
+  case -2: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
   case 18: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
   default: break
   }
@@ -681,13 +688,20 @@ func checkLiterals() {
 
   // No Diagnostics
   switch dbl {
+  case -3.5: break
+  case -2.5: break
+  case -1.5: break
   case 1.5: break
   case 2.5: break
   case 3.5: break
   default: break
   }
 
   switch dbl {
+  case -3.5: break
+  case -2.5: break // expected-note {{first occurrence of identical literal pattern is here}}
+  case -2.5: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}
+  case -1.5: break
   case 1.5: break
   case 2.5: break // expected-note {{first occurrence of identical literal pattern is here}}
   case 2.5: break // expected-warning {{literal value is already handled by previous pattern; consider removing it}}