Summary: I propose to create one or possibly several new public header files that will be used by both the C and C++ public APIs.
I would like to completely hide the dependency on APR from the public parts of the C++ API. In order to do that, public C++ headers must not include the C headers directly, because most if not all of them do expose APR. Up to now I've been "solving" this in an unsatisfactory and error-prone way, redefining enumeration values in C++ to be the same as in C, forward-declaring C structures in C++ headers, and so on. Instead, I'd like to extract certain parts of the C public API into a new header that is independent of APR, and use that in both APIs. This way I won't avoid redefining enumerations, for example, but I can ensure that both the C and C++ APIs use the same enumeration constant values. I'm attaching a patch that shows an example of what I have in mind. Please raise your objections by next year. :) -- Brane
Index: subversion/include/svn__impl__types.h =================================================================== --- subversion/include/svn__impl__types.h (nonexistent) +++ subversion/include/svn__impl__types.h (working copy) @@ -0,0 +1,95 @@ +/** + * @copyright + * ==================================================================== + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * ==================================================================== + * @endcopyright + * + * @file svn_types.h + * @brief Types implementation. + * This is a @b private implementation-specific header file. + * User code should not include it directly. + */ + +#ifndef SVN_X_IMPL_X_TYPES_H +#define SVN_X_IMPL_X_TYPES_H + +/* + * Define Subversion types that do not depend on APR or other + * external libraries (except for the C standard libvrary) and are + * shared betwen the C and C++ APIs. Do not include any headers + * except for the C standard library headers here. + */ + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Tristate values + * See: svn_tristate_t in svn_types.h + * tristate in svnxx/tristate.hpp + */ +enum svn__impl__tristate_t + { + /* This constant must not evaluate to either TRUE or FALSE. */ + svn__impl__tristate_false = 2, + svn__impl__tristate_true, + svn__impl__tristate_unknown + }; + +/* Depth values + * See: svn_depth_t in svn_types.h + * depth in svnxx/depth.hpp + */ +enum svn__impl__depth_t + { + svn__impl__depth_unknown = -2, + svn__impl__depth_exclude = -1, + svn__impl__depth_empty = 0, + svn__impl__depth_files = 1, + svn__impl__depth_immediates = 2, + svn__impl__depth_infinity = 3 + }; + +/* Revision number type + * See: svn_revnum_t in svn_types.h + * revision::number in svnxx/revision.hpp + */ +typedef long int svn__impl__revnum_t; +#define SVN__IMPL__INVALID_REVNUM ((svn__impl__revnum_t) -1) + +/* Revision kind + * See: svn_opt_revision_kind in svn_opt.h + * revision::kind in svnxx/revision.hpp + */ +enum svn__impl__revision_kind_t { + svn__impl__revision_unspecified, + svn__impl__revision_number, + svn__impl__revision_date, + svn__impl__revision_committed, + svn__impl__revision_previous, + svn__impl__revision_base, + svn__impl__revision_working, + svn__impl__revision_head +}; + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* SVN_X_IMPL_X_TYPES_H */ Index: subversion/include/svn_opt.h =================================================================== --- subversion/include/svn_opt.h (revision 1850008) +++ subversion/include/svn_opt.h (working copy) @@ -39,6 +39,7 @@ #include <apr_want.h> /* for FILE* */ #include "svn_types.h" +#include "svn__impl__types.h" #ifdef __cplusplus extern "C" { @@ -453,30 +454,31 @@ * with respect to its base revision. In other contexts, `working' * should behave the same as `committed' or `current'. */ +/* NOTE: See svn__impl__revision_kind_t in svn__impl__types.h. */ enum svn_opt_revision_kind { /** No revision information given. */ - svn_opt_revision_unspecified, + svn_opt_revision_unspecified = svn__impl__revision_unspecified, /** revision given as number */ - svn_opt_revision_number, + svn_opt_revision_number = svn__impl__revision_number, /** revision given as date */ - svn_opt_revision_date, + svn_opt_revision_date = svn__impl__revision_date, /** rev of most recent change */ - svn_opt_revision_committed, + svn_opt_revision_committed = svn__impl__revision_committed, /** (rev of most recent change) - 1 */ - svn_opt_revision_previous, + svn_opt_revision_previous = svn__impl__revision_previous, /** .svn/entries current revision */ - svn_opt_revision_base, + svn_opt_revision_base = svn__impl__revision_base, /** current, plus local mods */ - svn_opt_revision_working, + svn_opt_revision_working = svn__impl__revision_working, /** repository youngest */ - svn_opt_revision_head + svn_opt_revision_head = svn__impl__revision_head /* please update svn_opt__revision_to_string() when extending this enum */ }; Index: subversion/include/svn_types.h =================================================================== --- subversion/include/svn_types.h (revision 1850008) +++ subversion/include/svn_types.h (working copy) @@ -40,6 +40,8 @@ #include <apr_time.h> /* for apr_time_t */ #include <apr_strings.h> /* for apr_atoi64() */ +#include "svn__impl__types.h" + #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ @@ -354,14 +356,15 @@ * not a valid value. * * @since New in 1.7. */ +/* NOTE: See svn__impl__tristate_t in svn__impl__types.h. */ typedef enum svn_tristate_t { /** state known to be false (the constant does not evaulate to false) */ - svn_tristate_false = 2, + svn_tristate_false = svn__impl__tristate_false, /** state known to be true */ - svn_tristate_true, + svn_tristate_true = svn__impl__tristate_true, /** state could be true or false */ - svn_tristate_unknown + svn_tristate_unknown = svn__impl__tristate_unknown } svn_tristate_t; /** Return a constant string "true", "false" or NULL representing the value of @@ -423,19 +426,19 @@ /** A revision number. */ -typedef long int svn_revnum_t; +typedef svn__impl__revnum_t svn_revnum_t; /** Valid revision numbers begin at 0 */ #define SVN_IS_VALID_REVNUM(n) ((n) >= 0) /** The 'official' invalid revision num */ -#define SVN_INVALID_REVNUM ((svn_revnum_t) -1) +#define SVN_INVALID_REVNUM SVN__IMPL__INVALID_REVNUM /** Not really invalid...just unimportant -- one day, this can be its * own unique value, for now, just make it the same as * #SVN_INVALID_REVNUM. */ -#define SVN_IGNORED_REVNUM ((svn_revnum_t) -1) +#define SVN_IGNORED_REVNUM SVN__IMPL__INVALID_REVNUM /** Convert NULL-terminated C string @a str to a revision number. */ #define SVN_STR_TO_REV(str) ((svn_revnum_t) atol(str)) @@ -501,6 +504,7 @@ * * @since New in 1.5. */ +/* NOTE: See svn__impl__depth_t in svn__impl__types.h. */ typedef enum svn_depth_t { /* The order of these depths is important: the higher the number, @@ -510,7 +514,7 @@ /** Depth undetermined or ignored. In some contexts, this means the client should choose an appropriate default depth. The server will generally treat it as #svn_depth_infinity. */ - svn_depth_unknown = -2, + svn_depth_unknown = svn__impl__depth_unknown, /** Exclude (i.e., don't descend into) directory D. @note In Subversion 1.5, svn_depth_exclude is *not* supported @@ -521,26 +525,26 @@ svn_depth_exclude behavior, once we get a chance to implement client-side support for svn_depth_exclude.) */ - svn_depth_exclude = -1, + svn_depth_exclude = svn__impl__depth_exclude, /** Just the named directory D, no entries. Updates will not pull in any files or subdirectories not already present. */ - svn_depth_empty = 0, + svn_depth_empty = svn__impl__depth_empty, /** D + its file children, but not subdirs. Updates will pull in any files not already present, but not subdirectories. */ - svn_depth_files = 1, + svn_depth_files = svn__impl__depth_files, /** D + immediate children (D and its entries). Updates will pull in any files or subdirectories not already present; those subdirectories' this_dir entries will have depth-empty. */ - svn_depth_immediates = 2, + svn_depth_immediates = svn__impl__depth_immediates, /** D + all descendants (full recursion from D). Updates will pull in any files or subdirectories not already present; those subdirectories' this_dir entries will have depth-infinity. Equivalent to the pre-1.5 default update behavior. */ - svn_depth_infinity = 3 + svn_depth_infinity = svn__impl__depth_infinity } svn_depth_t; Index: subversion/bindings/cxx/include/svnxx/depth.hpp =================================================================== --- subversion/bindings/cxx/include/svnxx/depth.hpp (revision 1850008) +++ subversion/bindings/cxx/include/svnxx/depth.hpp (working copy) @@ -28,6 +28,8 @@ #include <cstdint> #include <string> +#include "svn__impl__types.h" + namespace apache { namespace subversion { namespace svnxx { @@ -35,15 +37,15 @@ /** * @brief The concept of depth for directories (see @ref svn_depth_t). */ -// NOTE: Keep these values identical to those in svn_depth_t! +// NOTE: See svn__impl__depth_t in svn__impl__types.h. enum class depth : std::int8_t { - unknown = -2, - exclude = -1, - empty = 0, - files = 1, - immediates = 2, - infinity = 3, + unknown = svn__impl__depth_unknown, + exclude = svn__impl__depth_exclude, + empty = svn__impl__depth_empty, + files = svn__impl__depth_files, + immediates = svn__impl__depth_immediates, + infinity = svn__impl__depth_infinity, }; /** Index: subversion/bindings/cxx/include/svnxx/revision.hpp =================================================================== --- subversion/bindings/cxx/include/svnxx/revision.hpp (revision 1850008) +++ subversion/bindings/cxx/include/svnxx/revision.hpp (working copy) @@ -28,6 +28,8 @@ #include <chrono> #include <cstdint> +#include "svn__impl__types.h" + #include "tristate.hpp" namespace apache { @@ -47,9 +49,9 @@ /** * @brief Revision number type. */ - enum class number : long + enum class number : svn__impl__revnum_t { - invalid = -1, ///< Invalid revision number. + invalid = SVN__IMPL__INVALID_REVNUM, ///< Invalid revision number. }; /** @@ -66,17 +68,17 @@ /** * @brief Revision kind discriminator (see @ref svn_opt_revision_kind). */ - // NOTE: Keep these values identical to those in svn_opt_revision_kind! + // NOTE: See svn__impl__revision_kind_t in svn__impl__types.h. enum class kind : std::int8_t { - unspecified, - number, - date, - committed, - previous, - base, - working, - head, + unspecified = svn__impl__revision_unspecified, + number = svn__impl__revision_number, + date = svn__impl__revision_date, + committed = svn__impl__revision_committed, + previous = svn__impl__revision_previous, + base = svn__impl__revision_base, + working = svn__impl__revision_working, + head = svn__impl__revision_head, }; /** Index: subversion/bindings/cxx/include/svnxx/tristate.hpp =================================================================== --- subversion/bindings/cxx/include/svnxx/tristate.hpp (revision 1850008) +++ subversion/bindings/cxx/include/svnxx/tristate.hpp (working copy) @@ -25,6 +25,9 @@ #ifndef SVNXX_TRISTATE_HPP #define SVNXX_TRISTATE_HPP +#include <cstdint> +#include "svn__impl__types.h" + #if defined(SVNXX_USE_BOOST) || defined(DOXYGEN) #include <boost/logic/tribool.hpp> #endif @@ -132,11 +135,11 @@ } private: - // See svn_tristate_t in svn_types.h. - enum: unsigned char { - false_value = 2, - true_value, - unknown_value + // NOTE: See svn__impl__tristate_t in svn__impl__types.h. + enum : std::uint8_t { + false_value = svn__impl__tristate_false, + true_value = svn__impl__tristate_true, + unknown_value = svn__impl__tristate_unknown } value; #if defined(SVNXX_USE_BOOST) || defined(DOXYGEN)
