diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h
--- a/clang/lib/Format/FormatToken.h
+++ b/clang/lib/Format/FormatToken.h
@@ -137,6 +137,10 @@
   TYPE(UntouchableMacroFunc)                                                   \
   /* like in begin : block */                                                  \
   TYPE(VerilogBlockLabelColon)                                                 \
+  /* The square bracket for the dimension part of the type name.               \
+   * In 'logic [1:0] x[1:0]', only the first '['. This way we can have space   \
+   * before the first bracket but not the second. */                           \
+  TYPE(VerilogDimensionedTypeName)                                             \
   /* for the base in a number literal, not including the quote */              \
   TYPE(VerilogNumberBase)                                                      \
   TYPE(Unknown)
@@ -1734,6 +1738,22 @@
                        kw_join_any, kw_join_none);
   }
 
+  /// Returns whether \p Tok is a Verilog keyword that opens a module, etc.
+  bool isVerilogHier(const FormatToken &Tok) const {
+    if (Tok.endsSequence(kw_function, kw_with))
+      return false;
+    if (Tok.is(kw_property)) {
+      const FormatToken *Prev = Tok.getPreviousNonComment();
+      return !(Prev &&
+               Prev->isOneOf(tok::kw_restrict, kw_assert, kw_assume, kw_cover));
+    }
+    return Tok.isOneOf(tok::kw_case, tok::kw_class, kw_function, kw_module,
+                       kw_interface, kw_package, kw_casex, kw_casez, kw_checker,
+                       kw_clocking, kw_covergroup, kw_macromodule, kw_primitive,
+                       kw_program, kw_property, kw_randcase, kw_randsequence,
+                       kw_task);
+  }
+
   /// Whether the token begins a block.
   bool isBlockBegin(const FormatToken &Tok, const FormatStyle &Style) const {
     return Tok.is(TT_MacroBlockBegin) ||
diff --git a/clang/lib/Format/TokenAnnotator.h b/clang/lib/Format/TokenAnnotator.h
--- a/clang/lib/Format/TokenAnnotator.h
+++ b/clang/lib/Format/TokenAnnotator.h
@@ -43,6 +43,7 @@
         MustBeDeclaration(Line.MustBeDeclaration), MightBeFunctionDecl(false),
         IsMultiVariableDeclStmt(false), Affected(false),
         LeadingEmptyLinesAffected(false), ChildrenAffected(false),
+        IsContinuation(Line.IsContinuation),
         FirstStartColumn(Line.FirstStartColumn) {
     assert(!Line.Tokens.empty());
 
@@ -143,6 +144,10 @@
   /// \c True if one of this line's children intersects with an input range.
   bool ChildrenAffected;
 
+  /// \c True if this line should be indented by ContinuationIndent in addition
+  /// to the normal indention level.
+  bool IsContinuation;
+
   unsigned FirstStartColumn;
 
 private:
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -238,11 +238,13 @@
     }
 
     bool StartsObjCMethodExpr = false;
-    if (FormatToken *MaybeSel = OpeningParen.Previous) {
-      // @selector( starts a selector.
-      if (MaybeSel->isObjCAtKeyword(tok::objc_selector) && MaybeSel->Previous &&
-          MaybeSel->Previous->is(tok::at)) {
-        StartsObjCMethodExpr = true;
+    if (Style.isCpp()) {
+      if (FormatToken *MaybeSel = OpeningParen.Previous) {
+        // @selector( starts a selector.
+        if (MaybeSel->isObjCAtKeyword(tok::objc_selector) &&
+            MaybeSel->Previous && MaybeSel->Previous->is(tok::at)) {
+          StartsObjCMethodExpr = true;
+        }
       }
     }
 
@@ -761,7 +763,8 @@
           // Remember that this is a [[using ns: foo]] C++ attribute, so we
           // don't add a space before the colon (unlike other colons).
           CurrentToken->setType(TT_AttributeColon);
-        } else if (Left->isOneOf(TT_ArraySubscriptLSquare,
+        } else if (Style.isCpp() &&
+                   Left->isOneOf(TT_ArraySubscriptLSquare,
                                  TT_DesignatedInitializerLSquare)) {
           Left->setType(TT_ObjCMethodExpr);
           StartsObjCMethodExpr = true;
@@ -951,6 +954,8 @@
         if (Keywords.isVerilogEnd(*Tok->Previous) ||
             Keywords.isVerilogBegin(*Tok->Previous)) {
           Tok->setType(TT_VerilogBlockLabelColon);
+        } else if (Contexts.back().ContextKind == tok::l_square) {
+          Tok->setType(TT_BitFieldColon);
         }
         break;
       }
@@ -1229,6 +1234,8 @@
           Tok->Next->isNot(tok::l_paren)) {
         Tok->setType(TT_CSharpGenericTypeConstraint);
         parseCSharpGenericTypeConstraint();
+        if (Tok->getPreviousNonComment() == nullptr)
+          Line.IsContinuation = true;
       }
       break;
     case tok::arrow:
@@ -1410,8 +1417,8 @@
     IdentifierInfo *Info = CurrentToken->Tok.getIdentifierInfo();
     if ((Style.Language == FormatStyle::LK_Java &&
          CurrentToken->is(Keywords.kw_package)) ||
-        (Info && Info->getPPKeywordID() == tok::pp_import &&
-         CurrentToken->Next &&
+        (!Style.isVerilog() && Info &&
+         Info->getPPKeywordID() == tok::pp_import && CurrentToken->Next &&
          CurrentToken->Next->isOneOf(tok::string_literal, tok::identifier,
                                      tok::kw_static))) {
       next();
@@ -3970,6 +3977,11 @@
         (Left.is(TT_VerilogNumberBase) && Right.is(tok::numeric_constant))) {
       return false;
     }
+    // Add space between the type name and dimension like `logic [1:0]`.
+    if (Right.is(tok::l_square) &&
+        Left.isOneOf(TT_VerilogDimensionedTypeName, Keywords.kw_function)) {
+      return true;
+    }
     // Don't add spaces between a casting type and the quote or repetition count
     // and the brace.
     if ((Right.is(Keywords.kw_apostrophe) ||
@@ -4949,7 +4961,8 @@
 }
 
 void TokenAnnotator::printDebugInfo(const AnnotatedLine &Line) const {
-  llvm::errs() << "AnnotatedTokens(L=" << Line.Level << "):\n";
+  llvm::errs() << "AnnotatedTokens(L=" << Line.Level << ", T=" << Line.Type
+               << ", C=" << Line.IsContinuation << "):\n";
   const FormatToken *Tok = Line.First;
   while (Tok) {
     llvm::errs() << " M=" << Tok->MustBreakBefore
diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -71,7 +71,7 @@
     }
     if (static_cast<int>(Indent) + Offset >= 0)
       Indent += Offset;
-    if (Line.First->is(TT_CSharpGenericTypeConstraint))
+    if (Line.IsContinuation)
       Indent = Line.Level * Style.IndentWidth + Style.ContinuationIndentWidth;
   }
 
diff --git a/clang/lib/Format/UnwrappedLineParser.h b/clang/lib/Format/UnwrappedLineParser.h
--- a/clang/lib/Format/UnwrappedLineParser.h
+++ b/clang/lib/Format/UnwrappedLineParser.h
@@ -48,6 +48,10 @@
 
   bool MustBeDeclaration;
 
+  /// \c True if this line should be indented by ContinuationIndent in
+  /// addition to the normal indention level.
+  bool IsContinuation = false;
+
   /// If this \c UnwrappedLine closes a block in a sequence of lines,
   /// \c MatchingOpeningBlockLineIndex stores the index of the corresponding
   /// opening line. Otherwise, \c MatchingOpeningBlockLineIndex must be
@@ -173,6 +177,11 @@
   bool tryToParsePropertyAccessor();
   void tryToParseJSFunction();
   bool tryToParseSimpleAttribute();
+  void parseVerilogHierIdentifier();
+  void parseVerilogSensitivityList();
+  // Returns the number of levels of indentation in addition to the normal 1
+  // level for a block, used for indenting case labels.
+  unsigned parseVerilogHierHeader();
 
   // Used by addUnwrappedLine to denote whether to keep or remove a level
   // when resetting the line state.
diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -838,8 +838,13 @@
     }
   };
 
+  // Whether this is a Verilog-specific block that has a special header like a
+  // module.
+  const bool VerilogHier =
+      Style.isVerilog() && Keywords.isVerilogHier(*FormatTok);
   assert((FormatTok->isOneOf(tok::l_brace, TT_MacroBlockBegin) ||
-          (Style.isVerilog() && Keywords.isVerilogBegin(*FormatTok))) &&
+          (Style.isVerilog() &&
+           (Keywords.isVerilogBegin(*FormatTok) || VerilogHier))) &&
          "'{' or macro block token expected");
   FormatToken *Tok = FormatTok;
   const bool FollowedByComment = Tokens->peekNextToken()->is(tok::comment);
@@ -849,14 +854,20 @@
 
   // For Whitesmiths mode, jump to the next level prior to skipping over the
   // braces.
-  if (AddLevels > 0 && Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths)
+  if (!VerilogHier && AddLevels > 0 &&
+      Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths) {
     ++Line->Level;
+  }
 
   size_t PPStartHash = computePPHash();
 
   const unsigned InitialLevel = Line->Level;
-  nextToken(/*LevelDifference=*/AddLevels);
-  HandleVerilogBlockLabel();
+  if (VerilogHier) {
+    AddLevels += parseVerilogHierHeader();
+  } else {
+    nextToken(/*LevelDifference=*/AddLevels);
+    HandleVerilogBlockLabel();
+  }
 
   // Bail out if there are too many levels. Otherwise, the stack might overflow.
   if (Line->Level > 300)
@@ -1551,7 +1562,14 @@
     return;
   case tok::kw_extern:
     nextToken();
-    if (FormatTok->is(tok::string_literal)) {
+    if (Style.isVerilog()) {
+      // In Verilog and extern module declaration looks like a start of module.
+      // But there is no body and endmodule. So we handle it separately.
+      if (Keywords.isVerilogHier(*FormatTok)) {
+        parseVerilogHierHeader();
+        return;
+      }
+    } else if (FormatTok->is(tok::string_literal)) {
       nextToken();
       if (FormatTok->is(tok::l_brace)) {
         if (Style.BraceWrapping.AfterExternBlock)
@@ -1750,9 +1768,15 @@
         parseEnum();
       }
       break;
+    case tok::kw_class:
+      if (Style.isVerilog()) {
+        parseBlock();
+        addUnwrappedLine();
+        return;
+      }
+      LLVM_FALLTHROUGH;
     case tok::kw_struct:
     case tok::kw_union:
-    case tok::kw_class:
       if (parseStructLike())
         return;
       break;
@@ -1888,7 +1912,8 @@
       }
 
       if (Style.isVerilog()) {
-        if (Keywords.isVerilogBegin(*FormatTok)) {
+        if (Keywords.isVerilogBegin(*FormatTok) ||
+            Keywords.isVerilogHier(*FormatTok)) {
           parseBlock();
           addUnwrappedLine();
           return;
@@ -3998,6 +4023,136 @@
   addUnwrappedLine();
 }
 
+void UnwrappedLineParser::parseVerilogHierIdentifier() {
+  // consume things like a::`b.c[d:e] or a::*
+  while (true) {
+    if (FormatTok->isOneOf(tok::star, tok::period, tok::periodstar,
+                           tok::coloncolon, tok::hash) ||
+        Keywords.isVerilogIdentifier(*FormatTok)) {
+      nextToken();
+    } else if (FormatTok->is(tok::l_square)) {
+      parseSquare();
+    } else {
+      break;
+    }
+  }
+}
+
+void UnwrappedLineParser::parseVerilogSensitivityList() {
+  if (!FormatTok->is(tok::at))
+    return;
+  nextToken();
+  // A block event expression has 2 at signs.
+  if (FormatTok->is(tok::at))
+    nextToken();
+  switch (FormatTok->Tok.getKind()) {
+  case tok::star:
+    nextToken();
+    break;
+  case tok::l_paren:
+    parseParens();
+    break;
+  default:
+    parseVerilogHierIdentifier();
+    break;
+  }
+}
+
+unsigned UnwrappedLineParser::parseVerilogHierHeader() {
+  unsigned AddLevels = 0;
+
+  if (FormatTok->is(Keywords.kw_clocking)) {
+    nextToken();
+    if (Keywords.isVerilogIdentifier(*FormatTok))
+      nextToken();
+    parseVerilogSensitivityList();
+    if (FormatTok->is(tok::semi))
+      nextToken();
+  } else if (FormatTok->isOneOf(tok::kw_case, Keywords.kw_casex,
+                                Keywords.kw_casez, Keywords.kw_randcase,
+                                Keywords.kw_randsequence)) {
+    AddLevels += Style.IndentCaseLabels;
+    nextToken();
+    if (FormatTok->is(tok::l_paren))
+      parseParens();
+    if (FormatTok->isOneOf(Keywords.kw_inside, Keywords.kw_matches))
+      nextToken();
+    // The case header has no semicolon.
+  } else {
+    // "module" etc.
+    nextToken();
+    // all the words like the name of the module and specifiers like
+    // "automatic" and the width of function return type
+    while (true) {
+      if (FormatTok->is(tok::l_square)) {
+        auto Prev = FormatTok->getPreviousNonComment();
+        if (Prev && Keywords.isVerilogIdentifier(*Prev))
+          Prev->setFinalizedType(TT_VerilogDimensionedTypeName);
+        parseSquare();
+      } else if (Keywords.isVerilogIdentifier(*FormatTok) ||
+                 FormatTok->isOneOf(Keywords.kw_automatic, tok::kw_static)) {
+        nextToken();
+      } else {
+        break;
+      }
+    }
+
+    auto NewLine = [this]() {
+      addUnwrappedLine();
+      Line->IsContinuation = true;
+    };
+
+    // package imports
+    while (FormatTok->is(Keywords.kw_import)) {
+      NewLine();
+      nextToken();
+      parseVerilogHierIdentifier();
+      if (FormatTok->is(tok::semi))
+        nextToken();
+    }
+
+    // parameters and ports
+    if (FormatTok->is(Keywords.kw_verilogHash)) {
+      NewLine();
+      nextToken();
+      if (FormatTok->is(tok::l_paren))
+        parseParens();
+    }
+    if (FormatTok->is(tok::l_paren)) {
+      NewLine();
+      parseParens();
+    }
+
+    // extends and implements
+    if (FormatTok->is(Keywords.kw_extends)) {
+      NewLine();
+      nextToken();
+      parseVerilogHierIdentifier();
+      if (FormatTok->is(tok::l_paren))
+        parseParens();
+    }
+    if (FormatTok->is(Keywords.kw_implements)) {
+      NewLine();
+      do {
+        nextToken();
+        parseVerilogHierIdentifier();
+      } while (FormatTok->is(tok::comma));
+    }
+
+    // Coverage event for cover groups.
+    if (FormatTok->is(tok::at)) {
+      NewLine();
+      parseVerilogSensitivityList();
+    }
+
+    if (FormatTok->is(tok::semi))
+      nextToken(/*LevelDifference=*/1);
+    addUnwrappedLine();
+  }
+
+  return AddLevels;
+}
+
 LLVM_ATTRIBUTE_UNUSED static void printDebugInfo(const UnwrappedLine &Line,
                                                  StringRef Prefix = "") {
   llvm::dbgs() << Prefix << "Line(" << Line.Level
@@ -4035,6 +4190,7 @@
   Line->Tokens.clear();
   Line->MatchingOpeningBlockLineIndex = UnwrappedLine::kInvalidIndex;
   Line->FirstStartColumn = 0;
+  Line->IsContinuation = false;
 
   if (ClosesWhitesmithsBlock && AdjustLevel == LineLevel::Remove)
     --Line->Level;
diff --git a/clang/unittests/Format/FormatTestVerilog.cpp b/clang/unittests/Format/FormatTestVerilog.cpp
--- a/clang/unittests/Format/FormatTestVerilog.cpp
+++ b/clang/unittests/Format/FormatTestVerilog.cpp
@@ -139,6 +139,75 @@
                                 "x = x;"));
 }
 
+TEST_F(FormatTestVerilog, Hierarchy) {
+  verifyFormat("module x;\n"
+               "endmodule");
+  // Test that the end label is on the same line as the end keyword.
+  verifyFormat("module x;\n"
+               "endmodule : x");
+  // Test that things inside are indented.
+  verifyFormat("module x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endmodule");
+  verifyFormat("program x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endprogram");
+  verifyFormat("interface x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endinterface");
+  verifyFormat("task x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endtask");
+  verifyFormat("function x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endfunction");
+  verifyFormat("class x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endclass");
+  // Test that they nest.
+  verifyFormat("module x;\n"
+               "  program x;\n"
+               "    program x;\n"
+               "    endprogram\n"
+               "  endprogram\n"
+               "endmodule");
+  // Test that an extern declaration doesn't change the indentation.
+  verifyFormat("extern module x;\n"
+               "x = x;");
+  // Test complex headers
+  verifyFormat("extern module x\n"
+               "    import x.x::x::*;\n"
+               "    import x;\n"
+               "    #(parameter x)\n"
+               "    (output x);");
+  verifyFormat("module x\n"
+               "    import x.x::x::*;\n"
+               "    import x;\n"
+               "    #(parameter x)\n"
+               "    (output x);\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endmodule : x");
+  verifyFormat("virtual class x\n"
+               "    (x)\n"
+               "    extends x(x)\n"
+               "    implements x, x, x;\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endclass : x\n");
+  verifyFormat("function automatic logic [1 : 0] x\n"
+               "    (input x);\n"
+               "  generate\n"
+               "  endgenerate\n"
+               "endfunction : x");
+}
+
 TEST_F(FormatTestVerilog, If) {
   verifyFormat("if (x)\n"
                "  x = x;");
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -868,6 +868,13 @@
   ASSERT_EQ(Tokens.size(), 7u);
   EXPECT_TOKEN(Tokens[1], tok::colon, TT_VerilogBlockLabelColon);
   EXPECT_TOKEN(Tokens[4], tok::colon, TT_VerilogBlockLabelColon);
+  // Test that the dimension colon is annotated correctly.
+  Tokens = Annotate("var [1 : 0] x;");
+  ASSERT_EQ(Tokens.size(), 9u) << Tokens;
+  EXPECT_TOKEN(Tokens[3], tok::colon, TT_BitFieldColon);
+  Tokens = Annotate("extern function [1 : 0] x;");
+  ASSERT_EQ(Tokens.size(), 10u) << Tokens;
+  EXPECT_TOKEN(Tokens[4], tok::colon, TT_BitFieldColon);
 }
 
 } // namespace