diff --git a/flang/include/flang/Evaluate/expression.h b/flang/include/flang/Evaluate/expression.h
--- a/flang/include/flang/Evaluate/expression.h
+++ b/flang/include/flang/Evaluate/expression.h
@@ -749,7 +749,7 @@
 public:
   using Result = SomeKind<CAT>;
   EVALUATE_UNION_CLASS_BOILERPLATE(Expr)
-  int GetKind() const;
+  int kind() const;
   common::MapTemplate<evaluate::Expr, CategoryTypes<CAT>> u;
 };
 
@@ -757,7 +757,7 @@
 public:
   using Result = SomeCharacter;
   EVALUATE_UNION_CLASS_BOILERPLATE(Expr)
-  int GetKind() const;
+  int kind() const;
   std::optional<Expr<SubscriptInteger>> LEN() const;
   common::MapTemplate<Expr, CategoryTypes<TypeCategory::Character>> u;
 };
diff --git a/flang/include/flang/Frontend/CompilerInstance.h b/flang/include/flang/Frontend/CompilerInstance.h
--- a/flang/include/flang/Frontend/CompilerInstance.h
+++ b/flang/include/flang/Frontend/CompilerInstance.h
@@ -58,7 +58,7 @@
   /// @name Compiler Invocation
   /// {
 
-  CompilerInvocation &GetInvocation() {
+  CompilerInvocation &invocation() {
     assert(invocation_ && "Compiler instance has no invocation!");
     return *invocation_;
   };
@@ -71,7 +71,7 @@
   /// {
 
   /// Return the current allSources.
-  Fortran::parser::AllSources &GetAllSources() const { return *allSources_; }
+  Fortran::parser::AllSources &allSources() const { return *allSources_; }
 
   bool HasAllSources() const { return allSources_ != nullptr; }
 
@@ -96,9 +96,9 @@
     return invocation_->GetDiagnosticOpts();
   }
 
-  FrontendOptions &GetFrontendOpts() { return invocation_->GetFrontendOpts(); }
-  const FrontendOptions &GetFrontendOpts() const {
-    return invocation_->GetFrontendOpts();
+  FrontendOptions &frontendOpts() { return invocation_->frontendOpts(); }
+  const FrontendOptions &frontendOpts() const {
+    return invocation_->frontendOpts();
   }
 
   /// }
diff --git a/flang/include/flang/Frontend/CompilerInvocation.h b/flang/include/flang/Frontend/CompilerInvocation.h
--- a/flang/include/flang/Frontend/CompilerInvocation.h
+++ b/flang/include/flang/Frontend/CompilerInvocation.h
@@ -46,8 +46,8 @@
 public:
   CompilerInvocation() = default;
 
-  FrontendOptions &GetFrontendOpts() { return frontendOpts_; }
-  const FrontendOptions &GetFrontendOpts() const { return frontendOpts_; }
+  FrontendOptions &frontendOpts() { return frontendOpts_; }
+  const FrontendOptions &frontendOpts() const { return frontendOpts_; }
 
   /// Create a compiler invocation from a list of input options.
   /// \returns true on success.
diff --git a/flang/include/flang/Frontend/FrontendAction.h b/flang/include/flang/Frontend/FrontendAction.h
--- a/flang/include/flang/Frontend/FrontendAction.h
+++ b/flang/include/flang/Frontend/FrontendAction.h
@@ -48,31 +48,31 @@
   /// @name Compiler Instance Access
   /// @{
 
-  CompilerInstance &GetCompilerInstance() const {
+  CompilerInstance &instance() const {
     assert(instance_ && "Compiler instance not registered!");
     return *instance_;
   }
 
-  void SetCompilerInstance(CompilerInstance *value) { instance_ = value; }
+  void set_instance(CompilerInstance *value) { instance_ = value; }
 
   /// @}
   /// @name Current File Information
   /// @{
 
-  const FrontendInputFile &GetCurrentInput() const { return currentInput_; }
+  const FrontendInputFile &currentInput() const { return currentInput_; }
 
   llvm::StringRef GetCurrentFile() const {
     assert(!currentInput_.IsEmpty() && "No current file!");
-    return currentInput_.GetFile();
+    return currentInput_.file();
   }
 
   llvm::StringRef GetCurrentFileOrBufferName() const {
     assert(!currentInput_.IsEmpty() && "No current file!");
     return currentInput_.IsFile()
-        ? currentInput_.GetFile()
-        : currentInput_.GetBuffer()->getBufferIdentifier();
+        ? currentInput_.file()
+        : currentInput_.buffer()->getBufferIdentifier();
   }
-  void SetCurrentInput(const FrontendInputFile &currentInput);
+  void set_currentInput(const FrontendInputFile &currentInput);
 
   /// @}
   /// @name Public Action Interface
diff --git a/flang/include/flang/Frontend/FrontendOptions.h b/flang/include/flang/Frontend/FrontendOptions.h
--- a/flang/include/flang/Frontend/FrontendOptions.h
+++ b/flang/include/flang/Frontend/FrontendOptions.h
@@ -91,18 +91,18 @@
   FrontendInputFile(const llvm::MemoryBuffer *buffer, InputKind kind)
       : buffer_(buffer), kind_(kind) {}
 
-  InputKind GetKind() const { return kind_; }
+  InputKind kind() const { return kind_; }
 
   bool IsEmpty() const { return file_.empty() && buffer_ == nullptr; }
   bool IsFile() const { return !IsBuffer(); }
   bool IsBuffer() const { return buffer_ != nullptr; }
 
-  llvm::StringRef GetFile() const {
+  llvm::StringRef file() const {
     assert(IsFile());
     return file_;
   }
 
-  const llvm::MemoryBuffer *GetBuffer() const {
+  const llvm::MemoryBuffer *buffer() const {
     assert(IsBuffer() && "Requested buffer_, but it is empty!");
     return buffer_;
   }
diff --git a/flang/lib/Evaluate/expression.cpp b/flang/lib/Evaluate/expression.cpp
--- a/flang/lib/Evaluate/expression.cpp
+++ b/flang/lib/Evaluate/expression.cpp
@@ -298,13 +298,13 @@
   delete p;
 }
 
-template <TypeCategory CAT> int Expr<SomeKind<CAT>>::GetKind() const {
+template <TypeCategory CAT> int Expr<SomeKind<CAT>>::kind() const {
   return std::visit(
       [](const auto &kx) { return std::decay_t<decltype(kx)>::Result::kind; },
       u);
 }
 
-int Expr<SomeCharacter>::GetKind() const {
+int Expr<SomeCharacter>::kind() const {
   return std::visit(
       [](const auto &kx) { return std::decay_t<decltype(kx)>::Result::kind; },
       u);
diff --git a/flang/lib/Frontend/CompilerInstance.cpp b/flang/lib/Frontend/CompilerInstance.cpp
--- a/flang/lib/Frontend/CompilerInstance.cpp
+++ b/flang/lib/Frontend/CompilerInstance.cpp
@@ -69,7 +69,7 @@
 
   // Get the path of the output file
   std::string outputFilePath =
-      GetOutputFilePath(GetFrontendOpts().outputFile_, baseName, extension);
+      GetOutputFilePath(frontendOpts().outputFile_, baseName, extension);
 
   // Create the output file
   std::unique_ptr<llvm::raw_pwrite_stream> os =
@@ -120,7 +120,7 @@
 bool CompilerInstance::ExecuteAction(FrontendAction &act) {
 
   // Connect Input to a CompileInstance
-  for (const FrontendInputFile &fif : GetFrontendOpts().inputs_) {
+  for (const FrontendInputFile &fif : frontendOpts().inputs_) {
     if (act.BeginSourceFile(*this, fif)) {
       if (llvm::Error err = act.Execute()) {
         consumeError(std::move(err));
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -176,7 +176,7 @@
   }
 
   // Parse the frontend args
-  ParseFrontendArgs(res.GetFrontendOpts(), args, diags);
+  ParseFrontendArgs(res.frontendOpts(), args, diags);
 
   return success;
 }
diff --git a/flang/lib/Frontend/FrontendAction.cpp b/flang/lib/Frontend/FrontendAction.cpp
--- a/flang/lib/Frontend/FrontendAction.cpp
+++ b/flang/lib/Frontend/FrontendAction.cpp
@@ -13,7 +13,7 @@
 
 using namespace Fortran::frontend;
 
-void FrontendAction::SetCurrentInput(const FrontendInputFile &currentInput) {
+void FrontendAction::set_currentInput(const FrontendInputFile &currentInput) {
   this->currentInput_ = currentInput;
 }
 
@@ -21,8 +21,8 @@
 // Deallocate compiler instance, input and output descriptors
 static void BeginSourceFileCleanUp(FrontendAction &fa, CompilerInstance &ci) {
   ci.ClearOutputFiles(/*EraseFiles=*/true);
-  fa.SetCurrentInput(FrontendInputFile());
-  fa.SetCompilerInstance(nullptr);
+  fa.set_currentInput(FrontendInputFile());
+  fa.set_instance(nullptr);
 }
 
 bool FrontendAction::BeginSourceFile(
@@ -31,8 +31,8 @@
   FrontendInputFile input(realInput);
   assert(!instance_ && "Already processing a source file!");
   assert(!realInput.IsEmpty() && "Unexpected empty filename!");
-  SetCurrentInput(realInput);
-  SetCompilerInstance(&ci);
+  set_currentInput(realInput);
+  set_instance(&ci);
   if (!ci.HasAllSources()) {
     BeginSourceFileCleanUp(*this, ci);
     return false;
@@ -41,7 +41,7 @@
 }
 
 bool FrontendAction::ShouldEraseOutputFiles() {
-  return GetCompilerInstance().getDiagnostics().hasErrorOccurred();
+  return instance().getDiagnostics().hasErrorOccurred();
 }
 
 llvm::Error FrontendAction::Execute() {
@@ -50,12 +50,12 @@
 }
 
 void FrontendAction::EndSourceFile() {
-  CompilerInstance &ci = GetCompilerInstance();
+  CompilerInstance &ci = instance();
 
   // Cleanup the output streams, and erase the output files if instructed by the
   // FrontendAction.
   ci.ClearOutputFiles(/*EraseFiles=*/ShouldEraseOutputFiles());
 
-  SetCompilerInstance(nullptr);
-  SetCurrentInput(FrontendInputFile());
+  set_instance(nullptr);
+  set_currentInput(FrontendInputFile());
 }
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -23,8 +23,8 @@
   bool binaryMode = true;
 
   // Set/store input file info into CompilerInstance.
-  CompilerInstance &ci = GetCompilerInstance();
-  Fortran::parser::AllSources &allSources{ci.GetAllSources()};
+  CompilerInstance &ci = instance();
+  Fortran::parser::AllSources &allSources{ci.allSources()};
   const Fortran::parser::SourceFile *sf;
   sf = allSources.Open(path, error_stream);
   llvm::ArrayRef<char> fileContent = sf->content();
diff --git a/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
--- a/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -24,7 +24,7 @@
 static std::unique_ptr<FrontendAction> CreateFrontendBaseAction(
     CompilerInstance &ci) {
 
-  ActionKind ak = ci.GetFrontendOpts().programAction_;
+  ActionKind ak = ci.frontendOpts().programAction_;
   switch (ak) {
   case InputOutputTest:
     return std::make_unique<InputOutputTestAction>();
@@ -52,7 +52,7 @@
 }
 bool ExecuteCompilerInvocation(CompilerInstance *flang) {
   // Honor -help.
-  if (flang->GetFrontendOpts().showHelp_) {
+  if (flang->frontendOpts().showHelp_) {
     clang::driver::getDriverOptTable().PrintHelp(llvm::outs(),
         "flang-new -fc1 [options] file...", "LLVM 'Flang' Compiler",
         /*Include=*/clang::driver::options::FC1Option,
@@ -62,7 +62,7 @@
   }
 
   // Honor -version.
-  if (flang->GetFrontendOpts().showVersion_) {
+  if (flang->frontendOpts().showVersion_) {
     llvm::cl::PrintVersionMessage();
     return true;
   }
diff --git a/flang/lib/Semantics/program-tree.h b/flang/lib/Semantics/program-tree.h
--- a/flang/lib/Semantics/program-tree.h
+++ b/flang/lib/Semantics/program-tree.h
@@ -56,7 +56,7 @@
       : name_{name}, spec_{spec}, exec_{exec} {}
 
   const parser::Name &name() const { return name_; }
-  Kind GetKind() const;
+  Kind kind() const;
   const Stmt &stmt() const { return stmt_; }
   bool isSpecificationPartResolved() const {
     return isSpecificationPartResolved_;
diff --git a/flang/lib/Semantics/program-tree.cpp b/flang/lib/Semantics/program-tree.cpp
--- a/flang/lib/Semantics/program-tree.cpp
+++ b/flang/lib/Semantics/program-tree.cpp
@@ -123,12 +123,12 @@
 }
 
 bool ProgramTree::IsModule() const {
-  auto kind{GetKind()};
+  auto kind{kind()};
   return kind == Kind::Module || kind == Kind::Submodule;
 }
 
 Symbol::Flag ProgramTree::GetSubpFlag() const {
-  return GetKind() == Kind::Function ? Symbol::Flag::Function
+  return kind() == Kind::Function ? Symbol::Flag::Function
                                      : Symbol::Flag::Subroutine;
 }
 
@@ -155,7 +155,7 @@
   return false;
 }
 
-ProgramTree::Kind ProgramTree::GetKind() const {
+ProgramTree::Kind ProgramTree::kind() const {
   return std::visit(
       common::visitors{
           [](const parser::Statement<parser::ProgramStmt> *) {
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -371,7 +371,7 @@
   DeclTypeSpec::Category GetDeclTypeSpecCategory() const {
     return state_.derived.category;
   }
-  KindExpr GetKindParamExpr(
+  KindExpr kindParamExpr(
       TypeCategory, const std::optional<parser::KindSelector> &);
   void CheckForAbstractType(const Symbol &typeSymbol);
 
@@ -1676,7 +1676,7 @@
   state_.declTypeSpec = &declTypeSpec;
 }
 
-KindExpr DeclTypeSpecVisitor::GetKindParamExpr(
+KindExpr DeclTypeSpecVisitor::kindParamExpr(
     TypeCategory category, const std::optional<parser::KindSelector> &kind) {
   return AnalyzeKindSelector(context(), category, kind);
 }
@@ -2176,7 +2176,7 @@
 
 const DeclTypeSpec &ScopeHandler::MakeNumericType(
     TypeCategory category, const std::optional<parser::KindSelector> &kind) {
-  KindExpr value{GetKindParamExpr(category, kind)};
+  KindExpr value{kindParamExpr(category, kind)};
   if (auto known{evaluate::ToInt64(value)}) {
     return context().MakeNumericType(category, static_cast<int>(*known));
   } else {
@@ -2186,7 +2186,7 @@
 
 const DeclTypeSpec &ScopeHandler::MakeLogicalType(
     const std::optional<parser::KindSelector> &kind) {
-  KindExpr value{GetKindParamExpr(TypeCategory::Logical, kind)};
+  KindExpr value{kindParamExpr(TypeCategory::Logical, kind)};
   if (auto known{evaluate::ToInt64(value)}) {
     return context().MakeLogicalType(static_cast<int>(*known));
   } else {
@@ -6367,7 +6367,7 @@
 
 // Push a new scope for this node or return false on error.
 bool ResolveNamesVisitor::BeginScopeForNode(const ProgramTree &node) {
-  switch (node.GetKind()) {
+  switch (node.kind()) {
     SWITCH_COVERS_ALL_CASES
   case ProgramTree::Kind::Program:
     PushScope(Scope::Kind::MainProgram,
diff --git a/flang/tools/flang-driver/fc1_main.cpp b/flang/tools/flang-driver/fc1_main.cpp
--- a/flang/tools/flang-driver/fc1_main.cpp
+++ b/flang/tools/flang-driver/fc1_main.cpp
@@ -46,7 +46,7 @@
       new clang::DiagnosticOptions();
   clang::DiagnosticsEngine diags(diagID, &*diagOpts, diagsBuffer);
   bool success =
-      CompilerInvocation::CreateFromArgs(flang->GetInvocation(), argv, diags);
+      CompilerInvocation::CreateFromArgs(flang->invocation(), argv, diags);
 
   diagsBuffer->FlushDiagnostics(flang->getDiagnostics());
 
diff --git a/flang/unittests/Frontend/CompilerInstanceTest.cpp b/flang/unittests/Frontend/CompilerInstanceTest.cpp
--- a/flang/unittests/Frontend/CompilerInstanceTest.cpp
+++ b/flang/unittests/Frontend/CompilerInstanceTest.cpp
@@ -47,7 +47,7 @@
   llvm::raw_string_ostream error_stream{buf};
   CompilerInstance compInst;
   const Fortran::parser::SourceFile *sf =
-      compInst.GetAllSources().Open(testFilePath, error_stream);
+      compInst.allSources().Open(testFilePath, error_stream);
 
   // 3. Verify the content of the input file
   // This is just a sanity check to make sure that CompilerInstance is capable
diff --git a/flang/unittests/Frontend/InputOutputTest.cpp b/flang/unittests/Frontend/InputOutputTest.cpp
--- a/flang/unittests/Frontend/InputOutputTest.cpp
+++ b/flang/unittests/Frontend/InputOutputTest.cpp
@@ -45,9 +45,9 @@
   CompilerInstance compInst;
   compInst.CreateDiagnostics();
   auto invocation = std::make_shared<CompilerInvocation>();
-  invocation->GetFrontendOpts().programAction_ = InputOutputTest;
+  invocation->frontendOpts().programAction_ = InputOutputTest;
   compInst.SetInvocation(std::move(invocation));
-  compInst.GetFrontendOpts().inputs_.push_back(
+  compInst.frontendOpts().inputs_.push_back(
       FrontendInputFile(/*File=*/testFilePath, Language::Fortran));
 
   // 3. Set-up the output stream. Using output buffer wrapped as an output