xbolva00 created this revision.
xbolva00 added a reviewer: aaron.ballman.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
Handle specific case
(2 ^ 64) - 1
Repository:
rC Clang
https://reviews.llvm.org/D66397
Files:
lib/Sema/SemaExpr.cpp
test/SemaCXX/warn-xor-as-pow.cpp
Index: test/SemaCXX/warn-xor-as-pow.cpp
===================================================================
--- test/SemaCXX/warn-xor-as-pow.cpp
+++ test/SemaCXX/warn-xor-as-pow.cpp
@@ -70,7 +70,20 @@
res = 2 ^ 32; // expected-warning {{result of '2 ^ 32' is 34; did you mean '1LL << 32'?}}
// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:9-[[@LINE-1]]:15}:"1LL << 32"
// expected-note@-2 {{replace expression with '0x2 ^ 32' to silence this warning}}
- res = 2 ^ 64;
+ res = (2 ^ 64) - 1; // expected-warning {{result of '2 ^ 64' is 66; did you mean '-1LL'?}}
+ // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:9-[[@LINE-1]]:21}:"-1LL"
+ // expected-note@-2 {{replace expression with '0x2 ^ 64' to silence this warning}}
+#define ULLONG_MAX 18446744073709551615ULL
+ res = (2 ^ 64) - 1; // expected-warning {{result of '2 ^ 64' is 66; did you mean 'ULLONG_MAX'?}}
+ // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:9-[[@LINE-1]]:21}:"ULLONG_MAX"
+ // expected-note@-2 {{replace expression with '0x2 ^ 64' to silence this warning}}
+ res = (2 ^ 64) - 2;
+ res = (2 ^ 65) - 1;
+ res = (2 + 64) - 1;
+ res = (3 ^ 64) - 1;
+ res = (2 ^ 8) - 1; // expected-warning {{result of '2 ^ 8' is 10; did you mean '1 << 8' (256)?}}
+ // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:15}:"1 << 8"
+ // expected-note@-2 {{replace expression with '0x2 ^ 8' to silence this warning}}
res = EPSILON;
res = 10 ^ 0; // expected-warning {{result of '10 ^ 0' is 10; did you mean '1e0'?}}
Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -9422,6 +9422,129 @@
<< RHSExpr->getSourceRange();
}
+static void diagnoseXorMisusedAsPow(Sema &S, const ExprResult &LHS,
+ const ExprResult &RHS,
+ const SourceLocation Loc,
+ const Expr *SubLHS = nullptr,
+ const Expr *SubRHS = nullptr) {
+ // Do not diagnose macros.
+ if (Loc.isMacroID())
+ return;
+
+ bool Negative = false;
+ const auto *LHSInt = dyn_cast<IntegerLiteral>(LHS.get());
+ const auto *RHSInt = dyn_cast<IntegerLiteral>(RHS.get());
+
+ if (!LHSInt)
+ return;
+ if (!RHSInt) {
+ // Check negative literals.
+ if (const auto *UO = dyn_cast<UnaryOperator>(RHS.get())) {
+ if (UO->getOpcode() != UO_Minus)
+ return;
+ RHSInt = dyn_cast<IntegerLiteral>(UO->getSubExpr());
+ if (!RHSInt)
+ return;
+ Negative = true;
+ } else {
+ return;
+ }
+ }
+
+ if (LHSInt->getValue().getBitWidth() != RHSInt->getValue().getBitWidth())
+ return;
+
+ CharSourceRange ExprRange = CharSourceRange::getCharRange(
+ LHSInt->getBeginLoc(), S.getLocForEndOfToken(RHSInt->getLocation()));
+ llvm::StringRef ExprStr =
+ Lexer::getSourceText(ExprRange, S.getSourceManager(), S.getLangOpts());
+
+ CharSourceRange XorRange =
+ CharSourceRange::getCharRange(Loc, S.getLocForEndOfToken(Loc));
+ llvm::StringRef XorStr =
+ Lexer::getSourceText(XorRange, S.getSourceManager(), S.getLangOpts());
+ // Do not diagnose if xor keyword/macro is used.
+ if (XorStr == "xor")
+ return;
+
+ const llvm::APInt &LeftSideValue = LHSInt->getValue();
+ const llvm::APInt &RightSideValue = RHSInt->getValue();
+ const llvm::APInt XorValue = LeftSideValue ^ RightSideValue;
+
+ std::string LHSStr = Lexer::getSourceText(
+ CharSourceRange::getTokenRange(LHSInt->getSourceRange()),
+ S.getSourceManager(), S.getLangOpts());
+ std::string RHSStr = Lexer::getSourceText(
+ CharSourceRange::getTokenRange(RHSInt->getSourceRange()),
+ S.getSourceManager(), S.getLangOpts());
+
+ int64_t RightSideIntValue = RightSideValue.getSExtValue();
+ if (Negative) {
+ RightSideIntValue = -RightSideIntValue;
+ RHSStr = "-" + RHSStr;
+ }
+
+ StringRef LHSStrRef = LHSStr;
+ StringRef RHSStrRef = RHSStr;
+ // Do not diagnose binary, hexadecimal, octal literals.
+ if (LHSStrRef.startswith("0b") || LHSStrRef.startswith("0B") ||
+ RHSStrRef.startswith("0b") || RHSStrRef.startswith("0B") ||
+ LHSStrRef.startswith("0x") || LHSStrRef.startswith("0X") ||
+ RHSStrRef.startswith("0x") || RHSStrRef.startswith("0X") ||
+ (LHSStrRef.size() > 1 && LHSStrRef.startswith("0")) ||
+ (RHSStrRef.size() > 1 && RHSStrRef.startswith("0")))
+ return;
+
+ if (SubLHS && SubRHS && (LeftSideValue != 2 || RightSideIntValue != 64))
+ return;
+
+ if (LeftSideValue == 2 && RightSideIntValue >= 0) {
+ std::string SuggestedExpr = "1 << " + RHSStr;
+ bool Overflow = false;
+ llvm::APInt One = (LeftSideValue - 1);
+ llvm::APInt PowValue = One.sshl_ov(RightSideValue, Overflow);
+ if (Overflow) {
+ if (RightSideIntValue < 64) {
+ S.Diag(Loc, diag::warn_xor_used_as_pow_base)
+ << ExprStr << XorValue.toString(10, true) << ("1LL << " + RHSStr)
+ << FixItHint::CreateReplacement(ExprRange, "1LL << " + RHSStr);
+ } else if (SubLHS && SubRHS && RightSideIntValue == 64) {
+ const auto *SubInt = dyn_cast<IntegerLiteral>(SubRHS);
+ if (SubInt && SubInt->getValue() == 1) {
+ SuggestedExpr = S.getPreprocessor().isMacroDefined("ULLONG_MAX")
+ ? "ULLONG_MAX"
+ : "-1LL";
+ ExprRange = CharSourceRange::getCharRange(
+ SubLHS->getBeginLoc(),
+ S.getLocForEndOfToken(SubInt->getLocation()));
+ S.Diag(Loc, diag::warn_xor_used_as_pow_base)
+ << ExprStr << XorValue.toString(10, true) << SuggestedExpr
+ << PowValue.toString(10, true)
+ << FixItHint::CreateReplacement(ExprRange, SuggestedExpr);
+ } else {
+ return;
+ }
+ } else {
+ return;
+ }
+ } else {
+ S.Diag(Loc, diag::warn_xor_used_as_pow_base_extra)
+ << ExprStr << XorValue.toString(10, true) << SuggestedExpr
+ << PowValue.toString(10, true)
+ << FixItHint::CreateReplacement(
+ ExprRange, (RightSideIntValue == 0) ? "1" : SuggestedExpr);
+ }
+
+ S.Diag(Loc, diag::note_xor_used_as_pow_silence) << ("0x2 ^ " + RHSStr);
+ } else if (LeftSideValue == 10) {
+ std::string SuggestedValue = "1e" + std::to_string(RightSideIntValue);
+ S.Diag(Loc, diag::warn_xor_used_as_pow_base)
+ << ExprStr << XorValue.toString(10, true) << SuggestedValue
+ << FixItHint::CreateReplacement(ExprRange, SuggestedValue);
+ S.Diag(Loc, diag::note_xor_used_as_pow_silence) << ("0xA ^ " + RHSStr);
+ }
+}
+
// C99 6.5.6
QualType Sema::CheckAdditionOperands(ExprResult &LHS, ExprResult &RHS,
SourceLocation Loc, BinaryOperatorKind Opc,
@@ -9536,6 +9659,11 @@
if (LHS.isInvalid() || RHS.isInvalid())
return QualType();
+ const auto *BO = dyn_cast<BinaryOperator>(LHS.get()->IgnoreParens());
+ if (BO && BO->getOpcode() == BO_Xor)
+ diagnoseXorMisusedAsPow(*this, BO->getLHS(), BO->getRHS(), Loc, LHS.get(),
+ RHS.get());
+
// Enforce type constraints: C99 6.5.6p3.
// Handle the common case first (both operands are arithmetic).
@@ -11011,107 +11139,6 @@
return GetSignedVectorType(vType);
}
-static void diagnoseXorMisusedAsPow(Sema &S, ExprResult &LHS, ExprResult &RHS,
- SourceLocation Loc) {
- // Do not diagnose macros.
- if (Loc.isMacroID())
- return;
-
- bool Negative = false;
- const auto *LHSInt = dyn_cast<IntegerLiteral>(LHS.get());
- const auto *RHSInt = dyn_cast<IntegerLiteral>(RHS.get());
-
- if (!LHSInt)
- return;
- if (!RHSInt) {
- // Check negative literals.
- if (const auto *UO = dyn_cast<UnaryOperator>(RHS.get())) {
- if (UO->getOpcode() != UO_Minus)
- return;
- RHSInt = dyn_cast<IntegerLiteral>(UO->getSubExpr());
- if (!RHSInt)
- return;
- Negative = true;
- } else {
- return;
- }
- }
-
- if (LHSInt->getValue().getBitWidth() != RHSInt->getValue().getBitWidth())
- return;
-
- CharSourceRange ExprRange = CharSourceRange::getCharRange(
- LHSInt->getBeginLoc(), S.getLocForEndOfToken(RHSInt->getLocation()));
- llvm::StringRef ExprStr =
- Lexer::getSourceText(ExprRange, S.getSourceManager(), S.getLangOpts());
-
- CharSourceRange XorRange =
- CharSourceRange::getCharRange(Loc, S.getLocForEndOfToken(Loc));
- llvm::StringRef XorStr =
- Lexer::getSourceText(XorRange, S.getSourceManager(), S.getLangOpts());
- // Do not diagnose if xor keyword/macro is used.
- if (XorStr == "xor")
- return;
-
- const llvm::APInt &LeftSideValue = LHSInt->getValue();
- const llvm::APInt &RightSideValue = RHSInt->getValue();
- const llvm::APInt XorValue = LeftSideValue ^ RightSideValue;
-
- std::string LHSStr = Lexer::getSourceText(
- CharSourceRange::getTokenRange(LHSInt->getSourceRange()),
- S.getSourceManager(), S.getLangOpts());
- std::string RHSStr = Lexer::getSourceText(
- CharSourceRange::getTokenRange(RHSInt->getSourceRange()),
- S.getSourceManager(), S.getLangOpts());
-
- int64_t RightSideIntValue = RightSideValue.getSExtValue();
- if (Negative) {
- RightSideIntValue = -RightSideIntValue;
- RHSStr = "-" + RHSStr;
- }
-
- StringRef LHSStrRef = LHSStr;
- StringRef RHSStrRef = RHSStr;
- // Do not diagnose binary, hexadecimal, octal literals.
- if (LHSStrRef.startswith("0b") || LHSStrRef.startswith("0B") ||
- RHSStrRef.startswith("0b") || RHSStrRef.startswith("0B") ||
- LHSStrRef.startswith("0x") || LHSStrRef.startswith("0X") ||
- RHSStrRef.startswith("0x") || RHSStrRef.startswith("0X") ||
- (LHSStrRef.size() > 1 && LHSStrRef.startswith("0")) ||
- (RHSStrRef.size() > 1 && RHSStrRef.startswith("0")))
- return;
-
- if (LeftSideValue == 2 && RightSideIntValue >= 0) {
- std::string SuggestedExpr = "1 << " + RHSStr;
- bool Overflow = false;
- llvm::APInt One = (LeftSideValue - 1);
- llvm::APInt PowValue = One.sshl_ov(RightSideValue, Overflow);
- if (Overflow) {
- if (RightSideIntValue < 64)
- S.Diag(Loc, diag::warn_xor_used_as_pow_base)
- << ExprStr << XorValue.toString(10, true) << ("1LL << " + RHSStr)
- << FixItHint::CreateReplacement(ExprRange, "1LL << " + RHSStr);
- else
- // TODO: 2 ^ 64 - 1
- return;
- } else {
- S.Diag(Loc, diag::warn_xor_used_as_pow_base_extra)
- << ExprStr << XorValue.toString(10, true) << SuggestedExpr
- << PowValue.toString(10, true)
- << FixItHint::CreateReplacement(
- ExprRange, (RightSideIntValue == 0) ? "1" : SuggestedExpr);
- }
-
- S.Diag(Loc, diag::note_xor_used_as_pow_silence) << ("0x2 ^ " + RHSStr);
- } else if (LeftSideValue == 10) {
- std::string SuggestedValue = "1e" + std::to_string(RightSideIntValue);
- S.Diag(Loc, diag::warn_xor_used_as_pow_base)
- << ExprStr << XorValue.toString(10, true) << SuggestedValue
- << FixItHint::CreateReplacement(ExprRange, SuggestedValue);
- S.Diag(Loc, diag::note_xor_used_as_pow_silence) << ("0xA ^ " + RHSStr);
- }
-}
-
QualType Sema::CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
SourceLocation Loc) {
// Ensure that either both operands are of the same vector type, or
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