From 657330ee0e41b90fa7f7b55fb7caa11f9c2c5369 Mon Sep 17 00:00:00 2001
From: Dmitri Gribenko <gribozavr@gmail.com>
Date: Mon, 5 Aug 2019 08:05:16 +0000
Subject: [PATCH] Adds a warning when an inline Doxygen comment has no argument

Summary:
It warns for for comments like
/** \pre \em */

where \em has no argument

This warning is enabled with the -Wdocumentation option.

Reviewers: gribozavr, rsmith

Reviewed By: gribozavr

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64696

Patch by Mark de Wever.

llvm-svn: 367809
---
 .../include/clang/Basic/DiagnosticCommentKinds.td  |  6 ++++
 clang/lib/AST/CommentParser.cpp                    |  6 ++++
 clang/test/Sema/warn-documentation.cpp             | 42 ++++++++++++++++++++++
 3 files changed, 54 insertions(+)

diff --git a/clang/include/clang/Basic/DiagnosticCommentKinds.td b/clang/include/clang/Basic/DiagnosticCommentKinds.td
index fcda3f3..d8ce258 100644
--- a/clang/include/clang/Basic/DiagnosticCommentKinds.td
+++ b/clang/include/clang/Basic/DiagnosticCommentKinds.td
@@ -153,6 +153,12 @@ def warn_doc_deprecated_not_sync : Warning<
 def note_add_deprecation_attr : Note<
   "add a deprecation attribute to the declaration to silence this warning">;
 
+// inline contents commands
+
+def warn_doc_inline_contents_no_argument : Warning<
+  "'%select{\\|@}0%1' command does not have an argument">,
+  InGroup<Documentation>, DefaultIgnore;
+
 // verbatim block commands
 
 def warn_verbatim_block_end_without_start : Warning<
diff --git a/clang/lib/AST/CommentParser.cpp b/clang/lib/AST/CommentParser.cpp
index c7f8aa7..29983b0 100644
--- a/clang/lib/AST/CommentParser.cpp
+++ b/clang/lib/AST/CommentParser.cpp
@@ -422,6 +422,12 @@ InlineCommandComment *Parser::parseInlineCommand() {
     IC = S.actOnInlineCommand(CommandTok.getLocation(),
                               CommandTok.getEndLocation(),
                               CommandTok.getCommandID());
+
+    Diag(CommandTok.getEndLocation().getLocWithOffset(1),
+         diag::warn_doc_inline_contents_no_argument)
+        << CommandTok.is(tok::at_command)
+        << Traits.getCommandInfo(CommandTok.getCommandID())->Name
+        << SourceRange(CommandTok.getLocation(), CommandTok.getEndLocation());
   }
 
   Retokenizer.putBackLeftoverTokens();
diff --git a/clang/test/Sema/warn-documentation.cpp b/clang/test/Sema/warn-documentation.cpp
index 5083f68..df7e189 100644
--- a/clang/test/Sema/warn-documentation.cpp
+++ b/clang/test/Sema/warn-documentation.cpp
@@ -1044,6 +1044,48 @@ template <>
 template <typename B>
 void test_attach38<int>::test_attach39(int, B);
 
+// The inline comments expect a string after the command.
+// expected-warning@+1 {{'\a' command does not have an argument}}
+/// \a
+int test_inline_no_argument_a_bad(int);
+
+/// \a A
+int test_inline_no_argument_a_good(int);
+
+// expected-warning@+1 {{'@b' command does not have an argument}}
+/// @b
+int test_inline_no_argument_b_bad(int);
+
+/// @b A
+int test_inline_no_argument_b_good(int);
+
+// expected-warning@+1 {{'\c' command does not have an argument}}
+/// \c
+int test_inline_no_argument_c_bad(int);
+
+/// \c A
+int test_inline_no_argument_c_good(int);
+
+// expected-warning@+1 {{'\e' command does not have an argument}}
+/// \e
+int test_inline_no_argument_e_bad(int);
+
+/// \e A
+int test_inline_no_argument_e_good(int);
+
+// expected-warning@+1 {{'\em' command does not have an argument}}
+/// \em
+int test_inline_no_argument_em_bad(int);
+
+/// \em A
+int test_inline_no_argument_em_good(int);
+
+// expected-warning@+1 {{'\p' command does not have an argument}}
+/// \p
+int test_inline_no_argument_p_bad(int);
+
+/// \p A
+int test_inline_no_argument_p_good(int);
 
 // PR13411, reduced.  We used to crash on this.
 /**
-- 
2.7.4