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Diffstat (limited to 'build2/rule.cxx')
| -rw-r--r-- | build2/rule.cxx | 309 |
1 files changed, 0 insertions, 309 deletions
diff --git a/build2/rule.cxx b/build2/rule.cxx deleted file mode 100644 index a09e28b..0000000 --- a/build2/rule.cxx +++ /dev/null @@ -1,309 +0,0 @@ -// file : build2/rule.cxx -*- C++ -*- -// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd -// license : MIT; see accompanying LICENSE file - -#include <build2/rule.hxx> - -#include <build2/scope.hxx> -#include <build2/target.hxx> -#include <build2/context.hxx> -#include <build2/algorithm.hxx> -#include <build2/filesystem.hxx> -#include <build2/diagnostics.hxx> - -using namespace std; -using namespace butl; - -namespace build2 -{ - // file_rule - // - // Note that this rule is special. It is the last, fallback rule. If - // it doesn't match, then no other rule can possibly match and we have - // an error. It also cannot be ambigious with any other rule. As a - // result the below implementation bends or ignores quite a few rules - // that normal implementations should follow. So you probably shouldn't - // use it as a guide to implement your own, normal, rules. - // - bool file_rule:: - match (action a, target& t, const string&) const - { - tracer trace ("file_rule::match"); - - // While strictly speaking we should check for the file's existence - // for every action (because that's the condition for us matching), - // for some actions this is clearly a waste. Say, perform_clean: we - // are not doing anything for this action so not checking if the file - // exists seems harmless. - // - switch (a) - { - case perform_clean_id: - return true; - default: - { - // While normally we shouldn't do any of this in match(), no other - // rule should ever be ambiguous with the fallback one and path/mtime - // access is atomic. In other words, we know what we are doing but - // don't do this in normal rules. - - // First check the timestamp. This takes care of the special "trust - // me, this file exists" situations (used, for example, for installed - // stuff where we know it's there, just not exactly where). - // - mtime_target& mt (t.as<mtime_target> ()); - - timestamp ts (mt.mtime ()); - - if (ts != timestamp_unknown) - return ts != timestamp_nonexistent; - - // Otherwise, if this is not a path_target, then we don't match. - // - path_target* pt (mt.is_a<path_target> ()); - if (pt == nullptr) - return false; - - const path* p (&pt->path ()); - - // Assign the path. - // - if (p->empty ()) - { - // Since we cannot come up with an extension, ask the target's - // derivation function to treat this as prerequisite (just like in - // search_existing_file()). - // - if (pt->derive_extension (true) == nullptr) - { - l4 ([&]{trace << "no default extension for target " << *pt;}); - return false; - } - - p = &pt->derive_path (); - } - - ts = mtime (*p); - pt->mtime (ts); - - if (ts != timestamp_nonexistent) - return true; - - l4 ([&]{trace << "no existing file for target " << *pt;}); - return false; - } - } - } - - recipe file_rule:: - apply (action a, target& t) const - { - /* - @@ outer - return noop_recipe; - */ - - // Update triggers the update of this target's prerequisites so it would - // seem natural that we should also trigger their cleanup. However, this - // possibility is rather theoretical so until we see a real use-case for - // this functionality, we simply ignore the clean operation. - // - if (a.operation () == clean_id) - return noop_recipe; - - // If we have no prerequisites, then this means this file is up to date. - // Return noop_recipe which will also cause the target's state to be set - // to unchanged. This is an important optimization on which quite a few - // places that deal with predominantly static content rely. - // - if (!t.has_group_prerequisites ()) // Group as in match_prerequisites(). - return noop_recipe; - - // Match all the prerequisites. - // - match_prerequisites (a, t); - - // Note that we used to provide perform_update() which checked that this - // target is not older than any of its prerequisites. However, later we - // realized this is probably wrong: consider a script with a testscript as - // a prerequisite; chances are the testscript will be newer than the - // script and there is nothing wrong with that. - // - return default_recipe; - } - - const file_rule file_rule::instance; - - // alias_rule - // - bool alias_rule:: - match (action, target&, const string&) const - { - return true; - } - - recipe alias_rule:: - apply (action a, target& t) const - { - // Inject dependency on our directory (note: not parent) so that it is - // automatically created on update and removed on clean. - // - inject_fsdir (a, t, false); - - match_prerequisites (a, t); - return default_recipe; - } - - const alias_rule alias_rule::instance; - - // fsdir_rule - // - bool fsdir_rule:: - match (action, target&, const string&) const - { - return true; - } - - recipe fsdir_rule:: - apply (action a, target& t) const - { - // Inject dependency on the parent directory. Note that it must be first - // (see perform_update_direct()). - // - inject_fsdir (a, t); - - match_prerequisites (a, t); - - switch (a) - { - case perform_update_id: return &perform_update; - case perform_clean_id: return &perform_clean; - default: assert (false); return default_recipe; - } - } - - static bool - fsdir_mkdir (const target& t, const dir_path& d) - { - // Even with the exists() check below this can still be racy so only print - // things if we actually did create it (similar to build2::mkdir()). - // - auto print = [&t, &d] () - { - if (verb >= 2) - text << "mkdir " << d; - else if (verb && current_diag_noise) - text << "mkdir " << t; - }; - - // Note: ignoring the dry_run flag. - // - mkdir_status ms; - - try - { - ms = try_mkdir (d); - } - catch (const system_error& e) - { - print (); - fail << "unable to create directory " << d << ": " << e << endf; - } - - if (ms == mkdir_status::success) - { - print (); - return true; - } - - return false; - } - - target_state fsdir_rule:: - perform_update (action a, const target& t) - { - target_state ts (target_state::unchanged); - - // First update prerequisites (e.g. create parent directories) then create - // this directory. - // - // @@ outer: should we assume for simplicity its only prereqs are fsdir{}? - // - if (!t.prerequisite_targets[a].empty ()) - ts = straight_execute_prerequisites (a, t); - - // The same code as in perform_update_direct() below. - // - const dir_path& d (t.dir); // Everything is in t.dir. - - // Generally, it is probably correct to assume that in the majority of - // cases the directory will already exist. If so, then we are going to get - // better performance by first checking if it indeed exists. See - // butl::try_mkdir() for details. - // - // @@ Also skip prerequisites? Can't we return noop in apply? - // - if (!exists (d) && fsdir_mkdir (t, d)) - ts |= target_state::changed; - - return ts; - } - - void fsdir_rule:: - perform_update_direct (action a, const target& t) - { - // First create the parent directory. If present, it is always first. - // - const target* p (t.prerequisite_targets[a].empty () - ? nullptr - : t.prerequisite_targets[a][0]); - - if (p != nullptr && p->is_a<fsdir> ()) - perform_update_direct (a, *p); - - // The same code as in perform_update() above. - // - const dir_path& d (t.dir); - - if (!exists (d)) - fsdir_mkdir (t, d); - } - - target_state fsdir_rule:: - perform_clean (action a, const target& t) - { - // The reverse order of update: first delete this directory, then clean - // prerequisites (e.g., delete parent directories). - // - // Don't fail if we couldn't remove the directory because it is not empty - // (or is current working directory). In this case rmdir() will issue a - // warning when appropriate. - // - target_state ts (rmdir (t.dir, t, current_diag_noise ? 1 : 2) - ? target_state::changed - : target_state::unchanged); - - if (!t.prerequisite_targets[a].empty ()) - ts |= reverse_execute_prerequisites (a, t); - - return ts; - } - - const fsdir_rule fsdir_rule::instance; - - // noop_rule - // - bool noop_rule:: - match (action, target&, const string&) const - { - return true; - } - - recipe noop_rule:: - apply (action, target&) const - { - return noop_recipe; - } - - const noop_rule noop_rule::instance; -} |