diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index bdaf264e9adce..f0412cddc6f19 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -3582,7 +3582,7 @@ tooling::Replacements sortJavaImports(const FormatStyle &Style, StringRef Code,
       ImportsInBlock.push_back(
           {Identifier, Line, Prev, AssociatedCommentLines, IsStatic});
       AssociatedCommentLines.clear();
-    } else if (Trimmed.size() > 0 && !ImportsInBlock.empty()) {
+    } else if (!Trimmed.empty() && !ImportsInBlock.empty()) {
       // Associating comments within the imports with the nearest import below
       AssociatedCommentLines.push_back(Line);
     }
diff --git a/clang/lib/Format/FormatTokenLexer.cpp b/clang/lib/Format/FormatTokenLexer.cpp
index 06f68ec8b0fc1..05dee26735cc9 100644
--- a/clang/lib/Format/FormatTokenLexer.cpp
+++ b/clang/lib/Format/FormatTokenLexer.cpp
@@ -1371,8 +1371,7 @@ FormatToken *FormatTokenLexer::getNextToken() {
       } else if (FormatTok->TokenText == "``") {
         FormatTok->Tok.setIdentifierInfo(nullptr);
         FormatTok->Tok.setKind(tok::hashhash);
-      } else if (Tokens.size() > 0 &&
-                 Tokens.back()->is(Keywords.kw_apostrophe) &&
+      } else if (!Tokens.empty() && Tokens.back()->is(Keywords.kw_apostrophe) &&
                  NumberBase.match(FormatTok->TokenText, &Matches)) {
         // In Verilog in a based number literal like `'b10`, there may be
         // whitespace between `'b` and `10`. Therefore we handle the base and
@@ -1420,7 +1419,7 @@ FormatToken *FormatTokenLexer::getNextToken() {
     tryParseJavaTextBlock();
   }
 
-  if (Style.isVerilog() && Tokens.size() > 0 &&
+  if (Style.isVerilog() && !Tokens.empty() &&
       Tokens.back()->is(TT_VerilogNumberBase) &&
       FormatTok->Tok.isOneOf(tok::identifier, tok::question)) {
     // Mark the number following a base like `'h?a0` as a number.
@@ -1454,9 +1453,9 @@ FormatToken *FormatTokenLexer::getNextToken() {
   if (Style.isCpp()) {
     auto *Identifier = FormatTok->Tok.getIdentifierInfo();
     auto it = Macros.find(Identifier);
-    if (!(Tokens.size() > 0 && Tokens.back()->Tok.getIdentifierInfo() &&
-          Tokens.back()->Tok.getIdentifierInfo()->getPPKeywordID() ==
-              tok::pp_define) &&
+    if ((Tokens.empty() || !Tokens.back()->Tok.getIdentifierInfo() ||
+         Tokens.back()->Tok.getIdentifierInfo()->getPPKeywordID() !=
+             tok::pp_define) &&
         it != Macros.end()) {
       FormatTok->setType(it->second);
       if (it->second == TT_IfMacro) {
diff --git a/clang/lib/Format/QualifierAlignmentFixer.cpp b/clang/lib/Format/QualifierAlignmentFixer.cpp
index b0dda65adfba1..441a37a4902b7 100644
--- a/clang/lib/Format/QualifierAlignmentFixer.cpp
+++ b/clang/lib/Format/QualifierAlignmentFixer.cpp
@@ -640,7 +640,7 @@ bool isPossibleMacro(const FormatToken *Tok) {
     return false;
 
   const auto Text = Tok->TokenText;
-  assert(Text.size() > 0);
+  assert(!Text.empty());
 
   // T,K,U,V likely could be template arguments
   if (Text.size() == 1)
diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index ac8c0c8fd0ec0..0adf7ee9ed543 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -223,8 +223,6 @@ class LineJoiner {
   tryFitMultipleLinesInOne(LevelIndentTracker &IndentTracker,
                            ArrayRef<AnnotatedLine *>::const_iterator I,
                            ArrayRef<AnnotatedLine *>::const_iterator E) {
-    const unsigned Indent = IndentTracker.getIndent();
-
     // Can't join the last line with anything.
     if (I + 1 == E)
       return 0;
@@ -240,6 +238,7 @@ class LineJoiner {
       return 0;
     }
 
+    const auto Indent = IndentTracker.getIndent();
     if (Style.ColumnLimit > 0 && Indent > Style.ColumnLimit)
       return 0;
 
@@ -1090,7 +1089,7 @@ class LineFormatter {
     const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
     bool HasLBrace = LBrace && LBrace->is(tok::l_brace) && LBrace->is(BK_Block);
     FormatToken &Previous = *State.NextToken->Previous;
-    if (Previous.Children.size() == 0 || (!HasLBrace && !LBrace->MacroParent)) {
+    if (Previous.Children.empty() || (!HasLBrace && !LBrace->MacroParent)) {
       // The previous token does not open a block. Nothing to do. We don't
       // assert so that we can simply call this function for all tokens.
       return true;
diff --git a/clang/lib/Format/WhitespaceManager.cpp b/clang/lib/Format/WhitespaceManager.cpp
index cfaadf07edfd0..cc3cc0f6906cc 100644
--- a/clang/lib/Format/WhitespaceManager.cpp
+++ b/clang/lib/Format/WhitespaceManager.cpp
@@ -314,7 +314,7 @@ AlignTokenSequence(const FormatStyle &Style, unsigned Start, unsigned End,
 
   for (unsigned i = Start; i != End; ++i) {
     auto &CurrentChange = Changes[i];
-    if (ScopeStack.size() != 0 &&
+    if (!ScopeStack.empty() &&
         CurrentChange.indentAndNestingLevel() <
             Changes[ScopeStack.back()].indentAndNestingLevel()) {
       ScopeStack.pop_back();
@@ -332,7 +332,7 @@ AlignTokenSequence(const FormatStyle &Style, unsigned Start, unsigned End,
       ScopeStack.push_back(i);
     }
 
-    bool InsideNestedScope = ScopeStack.size() != 0;
+    bool InsideNestedScope = !ScopeStack.empty();
     bool ContinuedStringLiteral = i > Start &&
                                   CurrentChange.Tok->is(tok::string_literal) &&
                                   Changes[i - 1].Tok->is(tok::string_literal);
@@ -1048,7 +1048,7 @@ void WhitespaceManager::alignChainedConditionals() {
           return C.Tok->is(TT_ConditionalExpr) &&
                  ((C.Tok->is(tok::question) && !C.NewlinesBefore) ||
                   (C.Tok->is(tok::colon) && C.Tok->Next &&
-                   (C.Tok->Next->FakeLParens.size() == 0 ||
+                   (C.Tok->Next->FakeLParens.empty() ||
                     C.Tok->Next->FakeLParens.back() != prec::Conditional)));
         },
         Changes, /*StartAt=*/0);
@@ -1057,7 +1057,7 @@ void WhitespaceManager::alignChainedConditionals() {
       FormatToken *Previous = C.Tok->getPreviousNonComment();
       return C.NewlinesBefore && Previous && Previous->is(TT_ConditionalExpr) &&
              (Previous->is(tok::colon) &&
-              (C.Tok->FakeLParens.size() == 0 ||
+              (C.Tok->FakeLParens.empty() ||
                C.Tok->FakeLParens.back() != prec::Conditional));
     };
     // Ensure we keep alignment of wrapped operands with non-wrapped operands