diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 74af9f869d08..42c3dcfd9863 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -7079,7 +7079,7 @@ ASTContext::getObjCEncodingForFunctionDecl(const FunctionDecl *Decl) const {
 void ASTContext::getObjCEncodingForMethodParameter(Decl::ObjCDeclQualifier QT,
                                                    QualType T, std::string& S,
                                                    bool Extended) const {
-  // Encode type qualifer, 'in', 'inout', etc. for the parameter.
+  // Encode type qualifier, 'in', 'inout', etc. for the parameter.
   getObjCEncodingForTypeQualifier(QT, S);
   // Encode parameter type.
   ObjCEncOptions Options = ObjCEncOptions()
@@ -7784,7 +7784,7 @@ void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string &S,
                                   .setExpandStructures()),
           FD);
       if (FD || Options.EncodingProperty() || Options.EncodeClassNames()) {
-        // Note that we do extended encoding of protocol qualifer list
+        // Note that we do extended encoding of protocol qualifier list
         // Only when doing ivar or property encoding.
         S += '"';
         for (const auto *I : OPT->quals()) {
@@ -10063,7 +10063,7 @@ QualType ASTContext::mergeTypes(QualType LHS, QualType RHS,
     unsigned LHSBits = LHS->castAs<ExtIntType>()->getNumBits();
     unsigned RHSBits = RHS->castAs<ExtIntType>()->getNumBits();
 
-    // Like unsigned/int, shouldn't have a type if they dont match.
+    // Like unsigned/int, shouldn't have a type if they don't match.
     if (LHSUnsigned != RHSUnsigned)
       return {};
 
@@ -10704,7 +10704,7 @@ static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
 }
 
 // On some targets such as PowerPC, some of the builtins are defined with custom
-// type decriptors for target-dependent types. These descriptors are decoded in
+// type descriptors for target-dependent types. These descriptors are decoded in
 // other functions, but it may be useful to be able to fall back to default
 // descriptor decoding to define builtins mixing target-dependent and target-
 // independent types. This function allows decoding one type descriptor with
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index c30d35ae884b..57aceec7d2a0 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -1824,7 +1824,7 @@ ASTNodeImporter::ImportDeclContext(DeclContext *FromDC, bool ForceImport) {
         RecordDecl *FromRecordDecl = nullptr;
         RecordDecl *ToRecordDecl = nullptr;
         // If we have a field that is an ArrayType we need to check if the array
-        // element is a RecordDecl and if so we need to import the defintion.
+        // element is a RecordDecl and if so we need to import the definition.
         if (FieldFrom->getType()->isArrayType()) {
           // getBaseElementTypeUnsafe(...) handles multi-dimensonal arrays for us.
           FromRecordDecl = FieldFrom->getType()->getBaseElementTypeUnsafe()->getAsRecordDecl();
diff --git a/clang/lib/AST/CommentBriefParser.cpp b/clang/lib/AST/CommentBriefParser.cpp
index 2b648cbb1d4b..2a5f7452b776 100644
--- a/clang/lib/AST/CommentBriefParser.cpp
+++ b/clang/lib/AST/CommentBriefParser.cpp
@@ -123,7 +123,7 @@ std::string BriefParser::Parse() {
         // We found a paragraph end.  This ends the brief description if
         // \command or its equivalent was explicitly used.
         // Stop scanning text because an explicit \paragraph is the
-        // preffered one.
+        // preferred one.
         if (InBrief)
           break;
         // End first paragraph if we found some non-whitespace text.
diff --git a/clang/lib/AST/ComparisonCategories.cpp b/clang/lib/AST/ComparisonCategories.cpp
index 896050482644..a42960ad3c7f 100644
--- a/clang/lib/AST/ComparisonCategories.cpp
+++ b/clang/lib/AST/ComparisonCategories.cpp
@@ -57,7 +57,7 @@ bool ComparisonCategoryInfo::ValueInfo::hasValidIntValue() const {
 
 /// Attempt to determine the integer value used to represent the comparison
 /// category result by evaluating the initializer for the specified VarDecl as
-/// a constant expression and retreiving the value of the class's first
+/// a constant expression and retrieving the value of the class's first
 /// (and only) field.
 ///
 /// Note: The STL types are expected to have the form:
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 82243f6b8d0c..119450480c1f 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -2337,7 +2337,7 @@ bool CXXMethodDecl::isUsualDeallocationFunction(
   // In C++17 onwards, all potential usual deallocation functions are actual
   // usual deallocation functions. Honor this behavior when post-C++14
   // deallocation functions are offered as extensions too.
-  // FIXME(EricWF): Destrying Delete should be a language option. How do we
+  // FIXME(EricWF): Destroying Delete should be a language option. How do we
   // handle when destroying delete is used prior to C++17?
   if (Context.getLangOpts().CPlusPlus17 ||
       Context.getLangOpts().AlignedAllocation ||
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index ec8b00a9eb7d..a25185067b9c 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -77,7 +77,7 @@ TemplateParameterList::TemplateParameterList(const ASTContext& C,
       if (TTP->hasTypeConstraint())
         HasConstrainedParameters = true;
     } else {
-      llvm_unreachable("unexpcted template parameter type");
+      llvm_unreachable("unexpected template parameter type");
     }
     // FIXME: If a default argument contains an unexpanded parameter pack, the
     // template parameter list does too.
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 2bba2a517413..296e9e7e5995 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -6759,7 +6759,7 @@ public:
                   SmallVectorImpl<unsigned char> &Output) const {
     for (CharUnits I = Offset, E = Offset + Width; I != E; ++I) {
       // If a byte of an integer is uninitialized, then the whole integer is
-      // uninitalized.
+      // uninitialized.
       if (!Bytes[I.getQuantity()])
         return false;
       Output.push_back(*Bytes[I.getQuantity()]);
diff --git a/clang/lib/AST/Interp/Descriptor.h b/clang/lib/AST/Interp/Descriptor.h
index b260b7600974..11072cab3e90 100644
--- a/clang/lib/AST/Interp/Descriptor.h
+++ b/clang/lib/AST/Interp/Descriptor.h
@@ -184,7 +184,7 @@ struct InlineDescriptor {
 
 /// Bitfield tracking the initialisation status of elements of primitive arrays.
 /// A pointer to this is embedded at the end of all primitive arrays.
-/// If the map was not yet created and nothing was initialied, the pointer to
+/// If the map was not yet created and nothing was initialized, the pointer to
 /// this structure is 0. If the object was fully initialized, the pointer is -1.
 struct InitMap {
 private:
diff --git a/clang/lib/AST/Interp/Function.h b/clang/lib/AST/Interp/Function.h
index 28531f04b6e9..ac1dffea1160 100644
--- a/clang/lib/AST/Interp/Function.h
+++ b/clang/lib/AST/Interp/Function.h
@@ -73,7 +73,7 @@ public:
   /// Returns the original FunctionDecl.
   const FunctionDecl *getDecl() const { return F; }
 
-  /// Returns the lcoation.
+  /// Returns the location.
   SourceLocation getLoc() const { return Loc; }
 
   /// Returns a parameter descriptor.
diff --git a/clang/lib/AST/Interp/InterpStack.h b/clang/lib/AST/Interp/InterpStack.h
index 127adb6b8eba..b02d3c6a34b0 100644
--- a/clang/lib/AST/Interp/InterpStack.h
+++ b/clang/lib/AST/Interp/InterpStack.h
@@ -69,7 +69,7 @@ private:
     return ((sizeof(T) + PtrAlign - 1) / PtrAlign) * PtrAlign;
   }
 
-  /// Grows the stack to accomodate a value and returns a pointer to it.
+  /// Grows the stack to accommodate a value and returns a pointer to it.
   void *grow(size_t Size);
   /// Returns a pointer from the top of the stack.
   void *peek(size_t Size);
diff --git a/clang/lib/AST/Interp/InterpState.h b/clang/lib/AST/Interp/InterpState.h
index c2209bbcbb92..57e36c4c63ea 100644
--- a/clang/lib/AST/Interp/InterpState.h
+++ b/clang/lib/AST/Interp/InterpState.h
@@ -46,7 +46,7 @@ public:
     return Parent.getBottomFrame();
   }
 
-  // Acces objects from the walker context.
+  // Access objects from the walker context.
   Expr::EvalStatus &getEvalStatus() const override {
     return Parent.getEvalStatus();
   }
diff --git a/clang/lib/AST/Interp/Opcodes.td b/clang/lib/AST/Interp/Opcodes.td
index 4aba5f5cd83c..638d5b3d2357 100644
--- a/clang/lib/AST/Interp/Opcodes.td
+++ b/clang/lib/AST/Interp/Opcodes.td
@@ -57,7 +57,7 @@ def ArgValueDecl : ArgType { let Name = "const ValueDecl *"; }
 def ArgRecordField : ArgType { let Name = "const Record::Field *"; }
 
 //===----------------------------------------------------------------------===//
-// Classes of types intructions operate on.
+// Classes of types instructions operate on.
 //===----------------------------------------------------------------------===//
 
 class TypeClass {
diff --git a/clang/lib/AST/Interp/Program.cpp b/clang/lib/AST/Interp/Program.cpp
index 10d42d533bae..e310c9678140 100644
--- a/clang/lib/AST/Interp/Program.cpp
+++ b/clang/lib/AST/Interp/Program.cpp
@@ -104,7 +104,7 @@ llvm::Optional<unsigned> Program::getGlobal(const ValueDecl *VD) {
   if (It != GlobalIndices.end())
     return It->second;
 
-  // Find any previous declarations which were aleady evaluated.
+  // Find any previous declarations which were already evaluated.
   llvm::Optional<unsigned> Index;
   for (const Decl *P = VD; P; P = P->getPreviousDecl()) {
     auto It = GlobalIndices.find(P);
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 63fc7e428c07..04baa85fe145 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -3603,7 +3603,7 @@ void MicrosoftMangleContextImpl::mangleCXXCatchableType(
   // FIXME: It is known that the Ctor is present in 2013, and in 2017.7
   // (_MSC_VER 1914) and newer, and that it's omitted in 2015 and 2017.4
   // (_MSC_VER 1911), but it's unknown when exactly it reappeared (1914?
-  // Or 1912, 1913 aleady?).
+  // Or 1912, 1913 already?).
   bool OmitCopyCtor = getASTContext().getLangOpts().isCompatibleWithMSVC(
                           LangOptions::MSVC2015) &&
                       !getASTContext().getLangOpts().isCompatibleWithMSVC(
diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index 5c86b06da835..d49b0aec42fe 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -1954,7 +1954,7 @@ void ItaniumRecordLayoutBuilder::LayoutField(const FieldDecl *D,
 
           // Since the combination of -mms-bitfields together with structs
           // like max_align_t (which contains a long double) for mingw is
-          // quite comon (and GCC handles it silently), just handle it
+          // quite common (and GCC handles it silently), just handle it
           // silently there. For other targets that have ms_struct enabled
           // (most probably via a pragma or attribute), trigger a diagnostic
           // that defaults to an error.
@@ -2631,7 +2631,7 @@ MicrosoftRecordLayoutBuilder::getAdjustedElementInfo(
   // Track zero-sized subobjects here where it's already available.
   EndsWithZeroSizedObject = Layout.endsWithZeroSizedObject();
   // Respect required alignment, this is necessary because we may have adjusted
-  // the alignment in the case of pragam pack.  Note that the required alignment
+  // the alignment in the case of pragma pack.  Note that the required alignment
   // doesn't actually apply to the struct alignment at this point.
   Alignment = std::max(Alignment, Info.Alignment);
   RequiredAlignment = std::max(RequiredAlignment, Layout.getRequiredAlignment());