diff options
Diffstat (limited to 'libbuild2/config/utility.hxx')
| -rw-r--r-- | libbuild2/config/utility.hxx | 58 |
1 files changed, 44 insertions, 14 deletions
diff --git a/libbuild2/config/utility.hxx b/libbuild2/config/utility.hxx index 1e2ff53..3b67c6c 100644 --- a/libbuild2/config/utility.hxx +++ b/libbuild2/config/utility.hxx @@ -29,13 +29,22 @@ namespace build2 // disfigure hooks (for example, for second-level configuration). These are // accessed through the config module entry points (which are NULL for // transient configurations). Note also that the exact interpretation of the - // save flags and module order depends on the config module implementation - // (which may ignore them as not applicable). An implementation may also - // define custom save flags (for example, accessible through the config.save - // attribute). Such flags should start from 0x100000000. + // save flags/function and module order depends on the config module + // implementation (which may ignore them as not applicable). An + // implementation may also define custom save flags (for example, accessible + // through the config.save attribute). Such flags should start from + // 0x100000000. + // + // See below for the save function (last argument) semantics. // LIBBUILD2_SYMEXPORT extern void - (*config_save_variable) (scope&, const variable&, optional<uint64_t>); + (*config_save_variable) (scope&, + const variable&, + optional<uint64_t>, + pair<names_view, const char*> (*)(const scope&, + const value&, + const value*, + names&)); LIBBUILD2_SYMEXPORT extern void (*config_save_environment) (scope&, const char*); @@ -75,11 +84,27 @@ namespace build2 const uint64_t save_false_omitted = 0x08; // Treat false as undefined. const uint64_t save_base = 0x10; // Custom save with base. + // The optional save function can be used to implement custom variable + // saving, for example, as a difference appended to the base value or to + // complete relative paths (if abs_dir_path does not fit). The base + // argument is the value of this variable from the outer scope (if any) + // and is only calculated if the save_base flag is specified. The second + // half of the result is the assignment operator to use. + // + using save_variable_function = + pair<names_view, const char*> (const scope& rs, + const value&, + const value* base, + names& storage); + inline void - save_variable (scope& rs, const variable& var, uint64_t flags = 0) + save_variable (scope& rs, + const variable& var, + uint64_t flags = 0, + save_variable_function* func = nullptr) { if (config_save_variable != nullptr) - config_save_variable (rs, var, flags); + config_save_variable (rs, var, flags, func); } // Mark a variable as "unsaved" (always transient). @@ -91,7 +116,7 @@ namespace build2 unsave_variable (scope& rs, const variable& var) { if (config_save_variable != nullptr) - config_save_variable (rs, var, nullopt); + config_save_variable (rs, var, nullopt, nullptr); } // Mark an environment variable to be saved during hermetic configuration. @@ -256,35 +281,40 @@ namespace build2 lookup lookup_config (scope& rs, const variable&, - uint64_t save_flags = 0); + uint64_t save_flags = 0, + save_variable_function* = nullptr); lookup lookup_config (bool& new_value, scope& rs, const variable&, - uint64_t save_flags = 0); + uint64_t save_flags = 0, + save_variable_function* = nullptr); // Note that the variable is expected to have already been entered. // inline lookup lookup_config (scope& rs, const string& var, - uint64_t save_flags = 0) + uint64_t save_flags = 0, + save_variable_function* func = nullptr) { // Note: go straight for the public variable pool. // - return lookup_config (rs, rs.ctx.var_pool[var], save_flags); + return lookup_config (rs, rs.ctx.var_pool[var], save_flags, func); } inline lookup lookup_config (bool& new_value, scope& rs, const string& var, - uint64_t save_flags = 0) + uint64_t save_flags = 0, + save_variable_function* func = nullptr) { // Note: go straight for the public variable pool. // - return lookup_config (new_value, rs, rs.ctx.var_pool[var], save_flags); + return lookup_config ( + new_value, rs, rs.ctx.var_pool[var], save_flags, func); } // Lookup a config.* variable value and, if the value is undefined, set it |