add macros for alloc/free of string types (#38)

Author: digama0

src/metamath.c

@@ -208,6 +208,8 @@ struct nullNmbrStruct {
     nmbrString nullElement; };
 extern struct nullNmbrStruct g_NmbrNull;
 #define NULL_NMBRSTRING &(g_NmbrNull.nullElement)
+#define nmbrString_def(x) nmbrString *x = NULL_NMBRSTRING
+#define free_nmbrString(x) nmbrLet(&x, NULL_NMBRSTRING)
 
 /* Null pntrString -- NULL flags the end of a pntrString */
 struct nullPntrStruct {
@@ -217,6 +219,8 @@ struct nullPntrStruct {
     pntrString nullElement; };
 extern struct nullPntrStruct g_PntrNull;
 #define NULL_PNTRSTRING &(g_PntrNull.nullElement)
+#define pntrString_def(x) pntrString *x = NULL_PNTRSTRING
+#define free_pntrString(x) pntrLet(&x, NULL_PNTRSTRING)
 
 
 /* This function returns a 1 if any entry in a comma-separated list

src/mmcmdl.c

@@ -20,7 +20,7 @@
 /* help0 is mostly for TOOLS help */
 void help0(vstring helpCmd) {
 
-vstring saveHelpCmd = "";
+vstring_def(saveHelpCmd);
 /* help0() may be called with a temporarily allocated argument (left(),
    cat(), etc.), and the let()s in the eventual print2() calls will
    deallocate and possibly corrupt helpCmd.  So, we grab a non-temporarily
@@ -346,7 +346,7 @@ H("For your convenience, the trailing quote is optional, for example:");
 H("    Tools> 'ls | more");
 H("");
 
-let(&saveHelpCmd, ""); /* Deallocate memory */
+free_vstring(saveHelpCmd); /* Deallocate memory */
 
 return;
 } /* help0 */
@@ -355,7 +355,7 @@ return;
 /* Note: help1 should contain Metamath help */
 void help1(vstring helpCmd) {
 
-vstring saveHelpCmd = "";
+vstring_def(saveHelpCmd);
 /* help1() may be called with a temporarily allocated argument (left(),
    cat(), etc.), and the let()s in the eventual print2() calls will
    deallocate and possibly corrupt helpCmd.  So, we grab a non-temporarily
@@ -1142,7 +1142,7 @@ H("GIF format unless ALT_HTML was previously set as shown in SHOW SETTINGS.");
 H("");
 
 
-let(&saveHelpCmd, ""); /* Deallocate memory */
+free_vstring(saveHelpCmd); /* Deallocate memory */
 return;
 
 } /* help1 */

src/mmcmds.c

@@ -18,7 +18,7 @@
 void help2(vstring helpCmd)
 {
 
-vstring saveHelpCmd = "";
+vstring_def(saveHelpCmd);
 /* help2() may be called with a temporarily allocated argument (left(),
    cat(), etc.), and the let()s in the eventual print2() calls will
    deallocate and possibly corrupt helpCmd.  So, we grab a non-temporarily
@@ -348,7 +348,7 @@ H("        statements are excluded when <label-match> contains wildcard");
 H("        characters.");
 H("");
 
-let(&saveHelpCmd, ""); /* Deallocate memory */
+free_vstring(saveHelpCmd); /* Deallocate memory */
 
 return;
 } /* help2 */
@@ -357,7 +357,7 @@ return;
 /* Split up help2 into help2 and help3 so lcc optimizer wouldn't overflow */
 void help3(vstring helpCmd) {
 
-vstring saveHelpCmd = "";
+vstring_def(saveHelpCmd);
 /* help3() may be called with a temporarily allocated argument (left(),
    cat(), etc.), and the let()s in the eventual print2() calls will
    deallocate and possibly corrupt helpCmd.  So, we grab a non-temporarily
@@ -1398,6 +1398,6 @@ H("will show all statements with subset then union in them.");
 H("");
 
 if (strcmp(helpCmd, saveHelpCmd)) bug(1401); /* helpCmd got corrupted */
-let(&saveHelpCmd, ""); /* Deallocate memory */
+free_vstring(saveHelpCmd); /* Deallocate memory */
 
 }