Merge pull request #247 from ecraven/master

Adding support for recursive aliases.

5 files changed, 72 insertions, 19 deletions

diff --git a/src/journal.cc b/src/journal.cc
index a014a964..007acd7b 100644
--- a/src/journal.cc
+++ b/src/journal.cc
@@ -96,6 +96,7 @@ void journal_t::initialize()
   check_payees      = false;
   day_break         = false;
   checking_style    = CHECK_PERMISSIVE;
+  recursive_aliases = false;
 }
 
 void journal_t::add_account(account_t * acct)
@@ -121,26 +122,9 @@ account_t * journal_t::find_account_re(const string& regexp)
 account_t * journal_t::register_account(const string& name, post_t * post,
                                         account_t * master_account)
 {
-  account_t * result = NULL;
-
-  // If there any account aliases, substitute before creating an account
+  // If there are any account aliases, substitute before creating an account
   // object.
-  if (account_aliases.size() > 0) {
-    accounts_map::const_iterator i = account_aliases.find(name);
-    if (i != account_aliases.end()) {
-      result = (*i).second;
-    } else {
-      // only check the very first account for alias expansion, in case
-      // that can be expanded successfully
-      size_t colon = name.find(':');
-      if(colon != string::npos) {
-        accounts_map::const_iterator j = account_aliases.find(name.substr(0, colon));
-        if (j != account_aliases.end()) {
-          result = find_account((*j).second->fullname() + name.substr(colon));
-        }
-      }
-    }
-  }
+  account_t * result = expand_aliases(name);
 
   // Create the account object and associate it with the journal; this
   // is registering the account.
@@ -178,7 +162,60 @@ account_t * journal_t::register_account(const string& name, post_t * post,
       }
     }
   }
+  return result;
+}
+
+account_t * journal_t::expand_aliases(string name) {
+  // Aliases are expanded recursively, so if both alias Foo=Bar:Foo and
+  // alias Bar=Baaz:Bar are in effect, first Foo will be expanded to Bar:Foo,
+  // then Bar:Foo will be expanded to Baaz:Bar:Foo.
+  // The expansion loop keeps a list of already expanded names in order to
+  // prevent infinite excursion. Each alias may only be expanded at most once.
+  account_t * result = NULL;
 
+  bool keep_expanding = true;
+  std::list<string> already_seen;
+  // loop until no expansion can be found
+  do {
+    if (account_aliases.size() > 0) {
+      accounts_map::const_iterator i = account_aliases.find(name);
+      if (i != account_aliases.end()) {
+        if(std::find(already_seen.begin(), already_seen.end(), name) != already_seen.end()) {
+          throw_(std::runtime_error,
+                 _f("Infinite recursion on alias expansion for %1%")
+                 % name);
+        }
+        // there is an alias for the full account name, including colons
+        already_seen.push_back(name);
+        result = (*i).second;
+        name = result->fullname();
+      } else {
+        // only check the very first account for alias expansion, in case
+        // that can be expanded successfully
+        size_t colon = name.find(':');
+        if(colon != string::npos) {
+          string first_account_name = name.substr(0, colon);
+          accounts_map::const_iterator j = account_aliases.find(first_account_name);
+          if (j != account_aliases.end()) {
+            if(std::find(already_seen.begin(), already_seen.end(), first_account_name) != already_seen.end()) {
+              throw_(std::runtime_error,
+                     _f("Infinite recursion on alias expansion for %1%")
+                     % first_account_name);
+            }
+            already_seen.push_back(first_account_name);
+            result = find_account((*j).second->fullname() + name.substr(colon));
+            name = result->fullname();
+          } else {
+            keep_expanding = false;
+          }
+        } else {
+          keep_expanding = false;
+        }
+      }
+    } else {
+      keep_expanding = false;
+    }
+  } while(keep_expanding && recursive_aliases);
   return result;
 }
 
diff --git a/src/journal.h b/src/journal.h
index 0d06e9f0..270a2912 100644
--- a/src/journal.h
+++ b/src/journal.h
@@ -131,6 +131,7 @@ public:
   bool                  force_checking;
   bool                  check_payees;
   bool                  day_break;
+  bool                  recursive_aliases;
   payee_mappings_t      payee_mappings;
   account_mappings_t    account_mappings;
   accounts_map          account_aliases;
@@ -167,6 +168,8 @@ public:
   account_t * find_account(const string& name, bool auto_create = true);
   account_t * find_account_re(const string& regexp);
 
+  account_t * expand_aliases(string name);
+
   account_t * register_account(const string& name, post_t * post,
                                account_t * master = NULL);
   string      register_payee(const string& name, xact_t * xact);
diff --git a/src/session.cc b/src/session.cc
index dbd49a0e..99467a43 100644
--- a/src/session.cc
+++ b/src/session.cc
@@ -113,6 +113,9 @@ std::size_t session_t::read_data(const string& master_account)
   if (HANDLED(day_break))
     journal->day_break = true;
 
+  if (HANDLED(recursive_aliases))
+    journal->recursive_aliases = true;
+  
   if (HANDLED(permissive))
     journal->checking_style = journal_t::CHECK_PERMISSIVE;
   else if (HANDLED(pedantic))
@@ -350,6 +353,9 @@ option_t<session_t> * session_t::lookup_option(const char * p)
     else OPT(pedantic);
     else OPT(permissive);
     break;
+  case 'r':
+    OPT(recursive_aliases);
+    break;
   case 's':
     OPT(strict);
     break;
diff --git a/src/session.h b/src/session.h
index 3572b991..c2345362 100644
--- a/src/session.h
+++ b/src/session.h
@@ -109,6 +109,7 @@ public:
     HANDLER(permissive).report(out);
     HANDLER(price_db_).report(out);
     HANDLER(price_exp_).report(out);
+    HANDLER(recursive_aliases).report(out);
     HANDLER(strict).report(out);
     HANDLER(value_expr_).report(out);
   }
@@ -164,6 +165,7 @@ public:
   OPTION(session_t, price_db_);
   OPTION(session_t, strict);
   OPTION(session_t, value_expr_);
+  OPTION(session_t, recursive_aliases);
 };
 
 /**
diff --git a/src/textual.cc b/src/textual.cc
index d8648c93..627a1835 100644
--- a/src/textual.cc
+++ b/src/textual.cc
@@ -977,6 +977,11 @@ void instance_t::account_alias_directive(account_t * account, string alias)
   // (account), add a reference to the account in the `account_aliases'
   // map, which is used by the post parser to resolve alias references.
   trim(alias);
+  // Ensure that no alias like "alias Foo=Foo" is registered.
+  if ( alias == account->fullname()) {
+    throw_(parse_error, _f("Illegal alias %1%=%2%")
+           % alias % account->fullname());
+  }
   std::pair<accounts_map::iterator, bool> result =
     context.journal->account_aliases.insert
       (accounts_map::value_type(alias, account));