Added new option and pragma to generate calls to a stack checking routine

git-svn-id: svn://svn.cc65.org/cc65/trunk@631 b7a2c559-68d2-44c3-8de9-860c34a00d81

src/cc65/codegen.c

@@ -525,7 +525,7 @@ void g_leave (int flags, int val)
      	    strcat (buf, "y");
      	} else {
 	    /* Y register no longer used */
-	    AddCodeHint ("y:-");	
+	    AddCodeHint ("y:-");
 	}
      	if (flags & CF_CONST) {
      	    if ((flags & CF_TYPE) != CF_LONG) {
@@ -2507,14 +2507,22 @@ void g_space (int space)
 /* Create or drop space on the stack */
 {
     if (space < 0) {
-	mod_internal (-space, "inc", "addy");
+     	mod_internal (-space, "inc", "addy");
     } else if (space > 0) {
-	mod_internal (space, "dec", "suby");
+     	mod_internal (space, "dec", "suby");
     }
 }
 
 
 
+void g_stackcheck (void)
+/* Check for a stack overflow */
+{
+    AddCodeLine ("\tjsr\tstkchk");
+}
+
+
+
 void g_add (unsigned flags, unsigned long val)
 /* Primary = TOS + Primary */
 {

src/cc65/codegen.h

@@ -371,6 +371,9 @@ void g_falsejump (unsigned flags, unsigned label);
 void g_space (int space);
 /* Create or drop space on the stack */
 
+void g_stackcheck (void);
+/* Check for a stack overflow */
+
 void g_add (unsigned flags, unsigned long val);
 void g_sub (unsigned flags, unsigned long val);
 void g_rsub (unsigned flags, unsigned long val);

src/cc65/global.c

@@ -58,6 +58,8 @@ unsigned char AddSource		= 0; 	/* Add source lines as comments */
 unsigned char DebugInfo		= 0;	/* Add debug info to the obj */
 unsigned char Debug		= 0;	/* Debug mode */
 unsigned char CreateDep		= 0;	/* Create a dependency file */
+unsigned char CheckStack	= 0;	/* Generate stack overflow checks */
+
 
 
 

src/cc65/global.h

@@ -59,6 +59,7 @@ extern unsigned char	AddSource;		/* Add source lines as comments */
 extern unsigned char	DebugInfo;		/* Add debug info to the obj */
 extern unsigned char	Debug;			/* Debug mode */
 extern unsigned char	CreateDep;		/* Create a dependency file */
+extern unsigned char	CheckStack;		/* Generate stack overflow checks */
 
 
 /* End of global.h */

src/cc65/locals.c

@@ -322,6 +322,9 @@ static void ParseOneDecl (const DeclSpec* Spec)
 void DeclareLocals (void)
 /* Declare local variables and types. */
 {
+    /* Remember the current stack pointer */
+    int InitialStack = oursp;
+
     /* Loop until we don't find any more variables */
     while (1) {
 
@@ -370,6 +373,13 @@ void DeclareLocals (void)
 
     /* In case we switched away from code segment, switch back now */
     g_usecode ();
+
+    /* In case we've allocated local variables in this block, emit a call to
+     * the stack checking routine if stack checks are enabled.
+     */
+    if (CheckStack && InitialStack != oursp) {
+	g_stackcheck ();
+    }
 }
 
 

src/cc65/main.c

@@ -97,6 +97,7 @@ static void Usage (void)
 	     "Long options:\n"
        	     "  --ansi\t\tStrict ANSI mode\n"
 	     "  --bss-name seg\tSet the name of the BSS segment\n"
+       	     "  --check-stack\tGenerate stack overflow checks\n"
        	     "  --code-name seg\tSet the name of the CODE segment\n"
        	     "  --cpu type\t\tSet cpu type\n"
        	     "  --data-name seg\tSet the name of the DATA segment\n"
@@ -293,6 +294,14 @@ static void OptBssName (const char* Opt, const char* Arg)
 
 
 
+static void OptCheckStack (const char* Opt, const char* Arg)
+/* Handle the --check-stack option */
+{
+    CheckStack = 1;
+}
+
+
+
 static void OptCodeName (const char* Opt, const char* Arg)
 /* Handle the --code-name option */
 {
@@ -433,6 +442,7 @@ int main (int argc, char* argv[])
 	{ "--add-source",	0,    	OptAddSource		},
 	{ "--ansi",   	 	0,	OptAnsi			},
 	{ "--bss-name",		1, 	OptBssName		},
+       	{ "--check-stack",	0,     	OptCheckStack		},
 	{ "--code-name",	1, 	OptCodeName		},
 	{ "--create-dep",	0,	OptCreateDep		},
         { "--cpu",     	       	1, 	OptCPU 			},
@@ -442,11 +452,11 @@ int main (int argc, char* argv[])
 	{ "--help",	 	0, 	OptHelp			},
 	{ "--include-dir",     	1,   	OptIncludeDir		},
 	{ "--rodata-name",	1, 	OptRodataName		},
-	{ "--signed-chars",	0, 	OptSignedChars		},
-       	{ "--static-locals",   	0, 	OptStaticLocals		},
-	{ "--target",	 	1,  	OptTarget		},
-	{ "--verbose",	       	0, 	OptVerbose		},
-	{ "--version",	       	0,	OptVersion		},
+	{ "--signed-chars",	0, 	OptSignedChars	       	},
+       	{ "--static-locals",   	0, 	OptStaticLocals	       	},
+	{ "--target",	 	1,  	OptTarget	       	},
+	{ "--verbose",	       	0, 	OptVerbose	       	},
+	{ "--version",	       	0,	OptVersion	       	},
     };
 
     int I;

src/cc65/pragma.c

@@ -58,6 +58,7 @@
 /* Tokens for the #pragmas */
 typedef enum {
     PR_BSSSEG,
+    PR_CHECKSTACK,
     PR_CODESEG,
     PR_DATASEG,
     PR_REGVARADDR,
@@ -74,6 +75,7 @@ static const struct Pragma {
     pragma_t	Tok;		/* Token */
 } Pragmas[] = {
     { 	"bssseg",       PR_BSSSEG	},
+    {	"checkstack",	PR_CHECKSTACK	},
     {   "codeseg",    	PR_CODESEG	},
     {   "dataseg",    	PR_DATASEG	},
     {   "regvaraddr", 	PR_REGVARADDR	},
@@ -217,6 +219,10 @@ void DoPragma (void)
 	    SegNamePragma (g_bssname);
 	    break;
 
+	case PR_CHECKSTACK:
+	    FlagPragma (&CheckStack);
+	    break;
+
 	case PR_CODESEG:
 	    SegNamePragma (g_codename);
 	    break;