Allow optional assignments in .export and .exportzp statements.

git-svn-id: svn://svn.cc65.org/cc65/trunk@3809 b7a2c559-68d2-44c3-8de9-860c34a00d81

doc/ca65.sgml

@@ -2158,19 +2158,25 @@ Here's a list of all control commands and a description, what they do:
 <sect1><tt>.EXPORT</tt><label id=".EXPORT"><p>
 
   Make symbols accessible from other modules. Must be followed by a comma
-  separated list of symbols to export, with each one optionally followed by
+  separated list of symbols to export, with each one optionally followed by an
-  an address specification. The default is to export the symbol with the
+  address specification and (also optional) an assignment. Using an additional
-  address size it actually has. The assembler will issue a warning, if the
+  assignment in the export statement allows to define and export a symbol in
-  symbol is exported with an address size smaller than the actual address
+  one statement. The default is to export the symbol with the address size it
-  size.
+  actually has. The assembler will issue a warning, if the symbol is exported
+  with an address size smaller than the actual address size.
 
-  Example:
+  Examples:
 
   <tscreen><verb>
 	.export	foo
         .export bar: far
+        .export foobar: far = foo * bar
+        .export baz := foobar, zap: far = baz - bar
   </verb></tscreen>
 
+  As with constant definitions, using <tt/:=/ instead of <tt/=/ marks the
+  symbols as a label.
+
   See: <tt><ref id=".EXPORTZP" name=".EXPORTZP"></tt>
 
 
@@ -2178,12 +2184,15 @@ Here's a list of all control commands and a description, what they do:
 
   Make symbols accessible from other modules. Must be followed by a comma
   separated list of symbols to export. The exported symbols are explicitly
-  marked as zero page symbols.
+  marked as zero page symbols. An assignment may be included in the
+  <tt/.EXPORTZP/ statement. This allows to define and export a symbol in one
+  statement.
 
-  Example:
+  Examples:
 
   <tscreen><verb>
   	.exportzp  foo, bar
+        .exportzp  baz := &dollar;02
   </verb></tscreen>
 
   See: <tt><ref id=".EXPORT" name=".EXPORT"></tt>

src/ca65/pseudo.c

@@ -165,6 +165,33 @@ static void SetBoolOption (unsigned char* Flag)
 
 
 
+static void ExportWithAssign (SymEntry* Sym, unsigned char AddrSize, unsigned Flags)
+/* Allow to assign the value of an export in an .export statement */
+{
+    /* The name and optional address size spec may be followed by an assignment
+     * or equal token.
+     */
+    if (Tok == TOK_ASSIGN || Tok == TOK_EQ) {
+
+        /* Assignment means the symbol is a label */
+        if (Tok == TOK_ASSIGN) {
+            Flags |= SF_LABEL;
+        }
+
+        /* Skip the assignment token */
+        NextTok ();
+
+        /* Define the symbol with the expression following the '=' */
+        SymDef (Sym, Expression(), ADDR_SIZE_DEFAULT, Flags);
+
+    }
+
+    /* Now export the symbol */
+    SymExport (Sym, AddrSize, Flags);
+}
+
+
+
 static void ExportImport (void (*Func) (SymEntry*, unsigned char, unsigned),
                           unsigned char DefAddrSize, unsigned Flags)
 /* Export or import symbols */
@@ -782,7 +809,7 @@ static void DoExitMacro (void)
 static void DoExport (void)
 /* Export a symbol */
 {
-    ExportImport (SymExport, ADDR_SIZE_DEFAULT, SF_NONE);
+    ExportImport (ExportWithAssign, ADDR_SIZE_DEFAULT, SF_NONE);
 }
 
 
@@ -790,7 +817,7 @@ static void DoExport (void)
 static void DoExportZP (void)
 /* Export a zeropage symbol */
 {
-    ExportImport (SymExport, ADDR_SIZE_ZP, SF_NONE);
+    ExportImport (ExportWithAssign, ADDR_SIZE_ZP, SF_NONE);
 }