Emit line directives for includes with directive on first line (#223)

* Emit line directives for includes with directive on first line
* Add nested include tests

Thanks to Nick Nobles for this bug report and fix

include/boost/wave/util/cpp_iterator.hpp

@@ -1578,9 +1578,9 @@ pp_iterator_functor<ContextT>::on_include_helper(char const* f, char const* s,
     char const* current_name = 0; // never try to match current file name
 #endif
 
-// call the 'found_include_directive' hook function
+    // call the 'found_include_directive' hook function
     if (ctx.get_hooks().found_include_directive(ctx.derived(), f, include_next))
-        return true;    // client returned false: skip file to include
+        return true;    // client returned true: skip file to include
 
     file_path = util::impl::unescape_lit(file_path);
     std::string native_path_str;
@@ -1607,6 +1607,7 @@ pp_iterator_functor<ContextT>::on_include_helper(char const* f, char const* s,
                 boost::wave::enable_prefer_pp_numbers(ctx.get_language()),
                 is_system ? base_iteration_context_type::system_header :
                             base_iteration_context_type::user_header));
+        new_iter_ctx->emitted_lines = (unsigned int)(-1); // force #line directive
 
         // call the include policy trace function
         ctx.get_hooks().opened_include_file(ctx.derived(), dir_path, file_path,

test/testwave/testfiles/t_5_040.cpp

@@ -0,0 +1,74 @@
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+    http://www.boost.org/
+
+    Copyright (c) 2024 Nick Nobles. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+// Line directives should be emitted for included files when they begin
+// with a single #if/#ifdef/#define directive. Addresses github issue #222.
+#include "t_5_040_001.hpp" // #if as first line should emit line directive
+#include "t_5_040_002.hpp" // #define as first line should emit line directive
+#include "t_5_040_003.hpp" // ensure nested includes emit line directive
+#include "t_5_040_005.hpp" // ensure empty initial lines produce line directive
+
+t_5_040_a
+#if 1
+t_5_040_b
+#endif
+
+//R #line 2 "t_5_040_001.hpp"
+//R t_5_040_001a
+//R #line 6 "t_5_040_001.hpp"
+//R t_5_040_001b
+//R 
+//R t_5_040_001c
+//R #line 2 "t_5_040_002.hpp"
+//R t_5_040_002
+//R #line 2 "t_5_040_004.hpp"
+//R t_5_040_004
+//R #line 2 "t_5_040_003.hpp"
+//R t_5_040_003
+//R #line 15 "t_5_040_005.hpp"
+//R t_5_040_005
+//R #line 17 "t_5_040.cpp"
+//R t_5_040_a
+//R 
+//R t_5_040_b
+
+//H 10: t_5_040.cpp(12): #include "t_5_040_001.hpp"
+//H 04: "t_5_040_001.hpp"
+//H 05: $S(t_5_040_001.hpp) ($B(t_5_040_001.hpp))
+//H 10: t_5_040_001.hpp(1): #if
+//H 11: t_5_040_001.hpp(1): #if 1: 1
+//H 10: t_5_040_001.hpp(3): #endif
+//H 10: t_5_040_001.hpp(7): #if
+//H 11: t_5_040_001.hpp(7): #if 1: 1
+//H 10: t_5_040_001.hpp(9): #endif
+//H 06: 
+//H 10: t_5_040.cpp(13): #include "t_5_040_002.hpp"
+//H 04: "t_5_040_002.hpp"
+//H 05: t_5_040_002.hpp ($B(t_5_040_002.hpp))
+//H 10: t_5_040_002.hpp(1): #define
+//H 08: t_5_040_002.hpp(1): t_5_040_002_hpp=
+//H 06: 
+//H 10: t_5_040.cpp(14): #include "t_5_040_003.hpp"
+//H 04: "t_5_040_003.hpp"
+//H 05: t_5_040_003.hpp ($B(t_5_040_003.hpp))
+//H 10: t_5_040_003.hpp(1): #include "t_5_040_004.hpp"
+//H 04: "t_5_040_004.hpp"
+//H 05: t_5_040_004.hpp ($B(t_5_040_004.hpp))
+//H 10: t_5_040_004.hpp(1): #if
+//H 11: t_5_040_004.hpp(1): #if 1: 1
+//H 10: t_5_040_004.hpp(3): #endif
+//H 06: 
+//H 06: 
+//H 10: t_5_040.cpp(15): #include "t_5_040_005.hpp"
+//H 04: "t_5_040_005.hpp"
+//H 05: t_5_040_005.hpp ($B(t_5_040_005.hpp))
+//H 06: 
+//H 10: t_5_040.cpp(18): #if
+//H 11: t_5_040.cpp(18): #if 1: 1
+//H 10: t_5_040.cpp(20): #endif

test/testwave/testfiles/t_5_040_001.hpp

@@ -0,0 +1,22 @@
+#if 1
+t_5_040_001a
+#endif
+
+//Ensure line directive still properly gets replaced with empty line
+t_5_040_001b
+#if 1
+t_5_040_001c
+#endif
+
+// Important: The #if must be the first line of this file to ensure proper testing
+// of line directive emission. Do not move the copyright comment to the
+// beginning of this file.
+
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+    http://www.boost.org/
+
+    Copyright (c) 2024 Nick Nobles. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/

test/testwave/testfiles/t_5_040_002.hpp

@@ -0,0 +1,15 @@
+#define t_5_040_002_hpp
+t_5_040_002
+
+// Important: The #define must be the first line of this file to ensure proper testing
+// of line directive emission. Do not move the copyright comment to the
+// beginning of this file.
+
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+    http://www.boost.org/
+
+    Copyright (c) 2024 Nick Nobles. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/

test/testwave/testfiles/t_5_040_003.hpp

@@ -0,0 +1,15 @@
+#include "t_5_040_004.hpp"
+t_5_040_003
+
+// Important: The #include must be the first line of this file to ensure proper testing
+// of line directive emission. Do not move the copyright comment to the
+// beginning of this file.
+
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+    http://www.boost.org/
+
+    Copyright (c) 2024 Nick Nobles. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/

test/testwave/testfiles/t_5_040_004.hpp

@@ -0,0 +1,16 @@
+#if 1
+t_5_040_004
+#endif
+
+// Important: The #if must be the first line of this file to ensure proper testing
+// of line directive emission. Do not move the copyright comment to the
+// beginning of this file.
+
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+    http://www.boost.org/
+
+    Copyright (c) 2024 Nick Nobles. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/

test/testwave/testfiles/t_5_040_005.hpp

@@ -0,0 +1,15 @@
+
+// Important: The first line of this file must be blank to ensure proper testing
+// of line directive emission. Do not move the copyright comment to the
+// beginning of this file.
+
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+    http://www.boost.org/
+
+    Copyright (c) 2024 Jeff Trull. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+t_5_040_005

test/testwave/testfiles/test.cfg

@@ -146,6 +146,7 @@ t_5_036.cpp
 t_5_037.cpp
 t_5_038.cpp
 t_5_039.cpp
+t_5_040.cpp
 
 #
 # unit tests from the mcpp preprocessor validation suite