Scanf improvements by Greg King

git-svn-id: svn://svn.cc65.org/cc65/trunk@3377 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/common/.cvsignore

@@ -29,7 +29,6 @@ puts.s
 qsort.s
 realloc.s
 rewind.s
-scanf.s
 sleep.s
 strftime.s
 strtok.s

libsrc/common/Makefile

@@ -1,5 +1,6 @@
+# -*- makefile -*-
 #
-# makefile for CC65 runtime library
+# makefile for CC65's common library
 #
 
 .SUFFIXES: .o .s .c
@@ -26,9 +27,19 @@ CFLAGS	= -Osir -g -T -t $(SYS) --forget-inc-paths -I . -I ../../include
 %.o:	%.s
 	@$(AS) -g -o $@ $(AFLAGS) $<
 
+#--------------------------------------------------------------------------
+# Rules to help us see what code the compiler and assembler make.
+
+%.s :	%.c
+	@$(CC) $(CFLAGS) -S $<
+
+%.lst :	%.s
+	@$(AS) $(AFLAGS) -l -o /dev/null $<
+
 #--------------------------------------------------------------------------
 # Object files
 
+# From C source-files
 C_OBJS =	_afailed.o	        \
                 _aligned_malloc.o       \
 		_hextab.o	        \
@@ -59,7 +70,6 @@ C_OBJS =	_afailed.o	        \
 		qsort.o		        \
 		realloc.o	        \
 		rewind.o	        \
-                scanf.o                 \
 		sleep.o		        \
                 strftime.o              \
 		strxfrm.o	        \
@@ -67,7 +77,7 @@ C_OBJS =	_afailed.o	        \
                 system.o                \
                 timezone.o
 
-
+# From assembly source-files
 S_OBJS = 	_cwd.o          \
                 _fdesc.o 	\
 	 	_file.o  	\
@@ -134,6 +144,7 @@ S_OBJS = 	_cwd.o          \
                 raise.o         \
                 remove.o        \
                 rename.o        \
+                scanf.o         \
 	 	setjmp.o      	\
                 signal.o        \
                 sigtable.o      \
@@ -183,10 +194,10 @@ S_OBJS = 	_cwd.o          \
 all:  	$(C_OBJS) $(S_OBJS)
 
 clean:
-	@rm -f *~
+	@$(RM) *~ *.lst
-	@rm -f $(C_OBJS:.o=.s)
+	@$(RM) $(C_OBJS:.o=.s)
-	@rm -f $(C_OBJS)
+	@$(RM) $(C_OBJS)
-	@rm -f $(S_OBJS)
+	@$(RM) $(S_OBJS)
 
 zap:	clean
 

libsrc/common/_scanf.h

@@ -1,7 +1,7 @@
 /*
  * _scanf.h
  *
- * (C) Copyright 2001 Ullrich von Bassewitz (uz@cc65.org)
+ * (c) Copyright 2004, Ullrich von Bassewitz <uz@cc65.org>
  *
  */
 
@@ -16,26 +16,26 @@
  * return EOF if no more data is available.
  */
 typedef int __fastcall__ (*getfunc) (void* data);
+
+/* Type of the function that is called to put back unused data */
 typedef int __fastcall__ (*ungetfunc) (int c, void* data);
 
 
 
 /* Control structure passed to the low level worker function.
  * Beware: This structure is mirrored in the _scanf.inc assembler include
- * file, so check this when altering the structure.                     
+ * file, so check this when altering the structure.
  */
 struct scanfdata {
-    getfunc    	    get;        /* Pointer to input routine */
+    getfunc	get;	/* Pointer to input routine */
-    ungetfunc       unget;      /* Pointer to pushback routine */
+    ungetfunc	unget;	/* Pointer to pushback routine */
-
+    void*	data;	/* Pointer to struct. used outside of _scanf() */
-    /* Fields used outside of _scanf */
-    void*           data;       /* Caller data */
 };
 
 
 
 /* Internal scanning routine */
-int __fastcall__ _scanf (struct scanfdata* d, const char* format, va_list ap);
+int __fastcall__ _scanf (const struct scanfdata* d, const char* format, va_list ap);
 
 
 
@@ -44,4 +44,3 @@ int __fastcall__ _scanf (struct scanfdata* d, const char* format, va_list ap);
 
 
 
-

libsrc/common/scanf.c

@@ -1,36 +0,0 @@
-/*
- * scanf.c
- *
- * Ullrich von Bassewitz (uz@cc65.org), 2004-11-26
- *
- */
-
-
-
-#include <stdio.h>
-
-
-
-/*****************************************************************************/
-/*     	    	  		     Code				     */
-/*****************************************************************************/
-
-
-
-int scanf (const char* format, ...)
-/* Standard C function */
-{
-    va_list ap;
-
-    /* Setup for variable arguments */
-    va_start (ap, format);
-
-    /* Call vfscanf(). Since we know that va_end won't do anything, we will
-     * save the call and return the value directly.
-     */
-    return vfscanf (stdin, format, ap);
-}
-
-
-
-

libsrc/common/scanf.s

@@ -0,0 +1,74 @@
+;
+; int scanf(const char* Format, ...);
+;
+; 2000-12-01, Ullrich von Bassewitz
+; 2004-12-31, Greg King
+;
+
+	.export		_scanf
+
+	.import		_stdin, pushax, addysp, _vfscanf
+	.import		sp:zp, ptr1:zp
+
+	.macpack	generic
+
+; ----------------------------------------------------------------------------
+; Code
+;
+_scanf:
+	sty	ArgSize		; Number of argument bytes passed in .Y
+
+; We are using a (hopefully) clever trick here to reduce code size.  On entry,
+; the stack pointer points to the last pushed argument of the variable
+; argument list.  Adding the number of argument bytes, would result in a
+; pointer that points _above_ the Format argument.
+; Because we have to push stdin anyway, we will do that here, so:
+;
+;   * we will save the subtraction of 2 (__fixargs__) later;
+;   * we will have the address of the Format argument which needs to
+;     be pushed next.
+
+	lda	_stdin
+	ldx	_stdin+1
+	jsr	pushax
+
+; Now, calculate the va_list pointer, which does point to Format.
+
+	lda	sp
+	ldx	sp+1
+	add	ArgSize
+	bcc	@L1
+	inx
+@L1:	sta	ptr1
+	stx	ptr1+1
+
+; Push a copy of Format.
+
+	ldy	#1
+	lda	(ptr1),y
+	tax
+	dey
+	lda	(ptr1),y
+	jsr	pushax
+
+; Load va_list [last and __fastcall__ argument to vfscanf()].
+
+	lda	ptr1
+	ldx	ptr1+1
+
+; Call vfscanf().
+
+	jsr	_vfscanf
+
+; Clean up the stack.  We will return what we got from vfscanf().
+
+	ldy	ArgSize
+	jmp	addysp
+
+; ----------------------------------------------------------------------------
+; Data
+;
+	.bss
+ArgSize:
+	.res	1		; Number of argument bytes
+

libsrc/common/vfscanf.s

@@ -1,14 +1,19 @@
 ;
 ; int __fastcall__ vfscanf (FILE* f, const char* format, va_list ap);
 ;
-; Ullrich von Bassewitz, 2004-11-27
+; 2004-11-27, Ullrich von Bassewitz
+; 2004-12-21, Greg King
 ;
 
   	.export	      	_vfscanf
-        .import         _fgetc, _ungetc
+        .import         _fgetc, _ungetc, _ferror
 
         .include        "zeropage.inc"
         .include        "_scanf.inc"
+        .include        "stdio.inc"
+
+
+count   :=      ptr3            ; Result of scan
 
 
 ; ----------------------------------------------------------------------------
@@ -25,23 +30,27 @@ d:      .addr   _fgetc          ; GET
 ; int __fastcall__ vfscanf (FILE* f, const char* format, va_list ap)
 ; /* Standard C function */
 ; {
-;     struct scanfdata d;
-;
 ;     /* Initialize the data struct. We do only need the given file as user data,
-;      * since the get and ungetc are crafted so they match the standard fgetc
+;      * because the (getfunc) and (ungetfunc) functions are crafted so that they
-;      * and ungetc functions.
+;      * match the standard-I/O fgetc() and ungetc().
 ;      */
-;     d.get    = (getfunc) fgetc,
+;     static struct scanfdata d = {
-;     d.unget  = (ungetfunc) ungetc,
+;         (  getfunc)  fgetc,
-;     d.data   = f;
+;         (ungetfunc) ungetc
+;     };
+;     static int count;
 ;
-;     /* Call the internal function and return the result */
+;     d.data = (void*) f;
-;     return _scanf (&d, format, ap);
+;
+;     /* Call the internal function */
+;     count = _scanf (&d, format, ap);
+;
+;     /* And, return the result */
+;     return ferror (f) ? EOF : count;
 ; }
 ;
-; Since _scanf has the same parameter stack as vfscanf, with f replaced by &d,
+; Because _scanf() has the same parameter stack as vfscanf(), with f replaced
-; we will do exactly that. _scanf will then clean up the stack, so we can jump
+; by &d, we will do exactly that.  _scanf() then will clean up the stack.
-; directly there, no need to return.
 ; Beware: Since ap is a fastcall parameter, we must not destroy a/x.
 ;
 
@@ -63,8 +72,27 @@ _vfscanf:
         lda     #>d
         sta     (sp),y
 
-; Restore the low byte of ap and jump to the _scanf function
+; Restore the low byte of ap, and call the _scanf function
 
         pla
-        jmp     __scanf
+        jsr     __scanf
+        sta     count
+        stx     count+1
+
+; Return -1 if there was a read error during the scan
+
+        lda     d + SCANFDATA::DATA     ; Get f
+        ldx     d + SCANFDATA::DATA+1
+        jsr     _ferror
+        tay
+        beq     L1
+        lda     #<EOF
+        tax
+        rts
+
+; Or, return the result of the scan
+
+L1:     lda     count
+        ldx     count+1
+        rts
 

libsrc/common/vsscanf.s

@@ -2,10 +2,12 @@
 ; int __fastcall__ vsscanf (const char* str, const char* format, va_list ap);
 ; /* Standard C function */
 ;
-; Ullrich von Bassewitz, 2004-11-28
+; 2004-11-28, Ullrich von Bassewitz
+; 2004-12-21, Greg King
 ;
 
 	.export	      	_vsscanf
+
 	.import		popax, __scanf
 	.importzp	sp, ptr1, ptr2
 
@@ -25,14 +27,13 @@
 ; static int __fastcall__ get (struct sscanfdata* d)
 ; /* Read a character from the input string and return it */
 ; {
-;     char C;
+;     char C = d->str[d->index];
-;     if (C = d->str[d->index]) {
+;     if (C == '\0') {
-;     	/* Increment index only if end not reached */
-;        	++d->index;
-;         return C;
-;     } else {
 ;         return EOF;
 ;     }
+;     /* Increment index only if end not reached */
+;     ++d->index;
+;     return C;
 ; }
 ;
 
@@ -73,17 +74,17 @@
 L1:     tax                             ; Save return value
         tya                             ; Low byte of index
         ldy     #SSCANFDATA::INDEX
-        add     #1
+        add     #<1
         sta     (ptr1),y
         iny
         lda     (ptr1),y
-        adc     #$00
+        adc     #>1
         sta     (ptr1),y
 
 ; Return the char just read
 
         txa
-        ldx     #$00
+        ldx     #>0
         rts
 
 .endproc
@@ -110,11 +111,11 @@ L1:     tax                             ; Save return value
 
         ldy     #SSCANFDATA::INDEX
         lda     (ptr1),y
-        sub     #1
+        sub     #<1
         sta     (ptr1),y
         iny
         lda     (ptr1),y
-        sbc     #0
+        sbc     #>1
         sta     (ptr1),y
 
 ; Return c
@@ -127,15 +128,16 @@ L1:     tax                             ; Save return value
 ; int __fastcall__ vsscanf (const char* str, const char* format, va_list ap)
 ; /* Standard C function */
 ; {
-;     struct sscanfdata sd;
-;     struct scanfdata d;
-;
 ;     /* Initialize the data structs. The sscanfdata struct will be passed back
-;      * to the get and unget functions by _scanf.
+;      * to the get and unget functions by _scanf().
 ;      */
-;     d.get    = (getfunc) get;
+;     static       struct sscanfdata sd;
-;     d.unget  = (ungetfunc) unget,
+;     static const struct  scanfdata  d = {
-;     d.data   = &sd;
+;         (  getfunc)   get,
+;         (ungetfunc) unget,
+;         (void*) &sd
+;     };
+;
 ;     sd.str   = str;
 ;     sd.index = 0;
 ;
@@ -144,10 +146,10 @@ L1:     tax                             ; Save return value
 ; }
 ;
 
-.data
+.bss
-
 sd:     .tag    SSCANFDATA
 
+.rodata
 d:      .addr   get
         .addr   unget
         .addr   sd
@@ -177,11 +179,10 @@ d:      .addr   get
         sta     sd + SSCANFDATA::INDEX
         sta     sd + SSCANFDATA::INDEX+1
 
-; Restore the low byte of ap and jump to _scanf which will cleanup the stacl
+; Restore the low byte of ap, and jump to _scanf() which will clean up the stack
 
         pla
         jmp     __scanf
 
 .endproc
 
-