diff options
Diffstat (limited to 'libbuild2/context.hxx')
| -rw-r--r-- | libbuild2/context.hxx | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/libbuild2/context.hxx b/libbuild2/context.hxx index 2a9c93e..5f6e810 100644 --- a/libbuild2/context.hxx +++ b/libbuild2/context.hxx @@ -348,14 +348,36 @@ namespace build2 // const variable* var_project_summary; - // import.* + // import.* and export.* // const variable* var_import_build2; const variable* var_import_target; - const variable* var_import_metadata; - // export.* + // The import.metadata variable and the --build2-metadata option are used + // to pass the metadata compatibility version. + // + // This serves both as an indication that the metadata is required (can be + // useful, for example, in cases where it is expensive to calculate) as + // well as the maximum version we recognize. The exporter may return it in + // any version up to and including this maximum. And it may return it even + // if not requested (but only in version 1). The exporter should also set + // the returned version as the target-specific export.metadata variable. + // + // The export.metadata value should start with the version optionally + // followed by the metadata variable prefix (for example, cli in + // cli.version). If the variable prefix is missing, it is assumed to be + // the target name as imported. + // + // The following metadata variable names have pre-defined meaning: // + // <var-prefix>.name = [string] # Stable name for diagnostics. + // <var-prefix>.version = [string] # Version for diagnostics. + // <var-prefix>.checksum = [string] # Checksum for change tracking. + // + // If the <var-prefix>.name variable is missing, it is set to the target + // name as imported. + // + const variable* var_import_metadata; const variable* var_export_metadata; // [string] target visibility |