Replace strdup by an assembler implementation

git-svn-id: svn://svn.cc65.org/cc65/trunk@186 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/common/.cvsignore b/libsrc/common/.cvsignore
index fabf0b023145e3b87f97d28f6160e7fe66fbbe2c..338c6bca56bd774deda6e9d9a6ce77e10b29cf00 100644 (file)
--- a/libsrc/common/.cvsignore
+++ b/libsrc/common/.cvsignore
@@ -1,7 +1,6 @@
 fclose.s
 fgets.s
 fprintf.s
-strdup.s
 calloc.s
 _fopen.s
 fputs.s

diff --git a/libsrc/common/Makefile b/libsrc/common/Makefile
index 98ca45efdb8bd07784dc76ea4f468d01eb18fef8..3c138635ac834eaae71db1c590893cbaa40e0837 100644 (file)
--- a/libsrc/common/Makefile
+++ b/libsrc/common/Makefile
@@ -13,7 +13,7 @@
        @echo $<
        @$(AS) -g -o $@ $(AFLAGS) $<
 
-C_OBJS = fclose.o fgets.o fprintf.o strdup.o calloc.o _fopen.o\
+C_OBJS = fclose.o fgets.o fprintf.o calloc.o _fopen.o\
         fputs.o fread.o fwrite.o gets.o realloc.o bsearch.o strxfrm.o\
         printf.o _hextab.o vfprintf.o fdopen.o strtok.o\
         _afailed.o fopen.o fgetc.o fputc.o puts.o gets.o perror.o getchar.o\
@@ -68,6 +68,7 @@ S_OBJS =      _fdesc.o        \
                strcoll.o       \
                strcpy.o        \
                strcspn.o       \
+               strdup.o        \
                strerror.o      \
                stricmp.o       \
                strlen.o        \

diff --git a/libsrc/common/strdup.c b/libsrc/common/strdup.c
deleted file mode 100644 (file)
index 42a01af..0000000
--- a/libsrc/common/strdup.c
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * strdup.c
- *
- * Ullrich von Bassewitz, 11.08.1998
- */
-
-
-
-#include <string.h>
-#include <stdlib.h>
-
-
-
-char* strdup (char* s)
-{
-    char* p;
-    p = malloc (strlen (s) + 1);
-    if (p) {
-       strcpy (p, s);
-    }
-    return p;
-}
-
-
-

diff --git a/libsrc/common/strdup.s b/libsrc/common/strdup.s
new file mode 100644 (file)
index 0000000..fa2d289
--- /dev/null
+++ b/libsrc/common/strdup.s
@@ -0,0 +1,80 @@
+;
+; Ullrich von Bassewitz, 18.07.2000
+;
+; char* __fastcall__ strdup (const char* S);
+;
+; Note: The code knowns which zero page locations are used by malloc.
+;
+
+       .importzp       sp, tmp1, ptr4
+       .import         pushax, decsp4, incsp4
+       .import         _strlen, _malloc, _memcpy
+       .export         _strdup
+
+       .macpack        generic
+
+_strdup:
+
+; Since we need some place to store the intermediate results, allocate a
+; stack frame. To make this somewhat more efficient, create the stackframe
+; as needed for the final call to the memcpy function.
+
+       jsr     decsp4          ; Target/source
+
+; Store the pointer into the source slot
+
+       ldy     #0
+       sta     (sp),y
+       iny
+       pha
+       txa
+       sta     (sp),y
+       pla
+
+; Get length of S (which is still in a/x)
+
+       jsr     _strlen
+
+; Calculate strlen(S)+1 (the space needed)
+
+       add     #1
+       bcc     @L1
+       inx
+
+; Save the space we're about to allocate in ptr4
+
+@L1:   sta     ptr4
+       stx     ptr4+1
+
+; Allocate memory. _malloc will not use ptr4
+
+       jsr     _malloc
+
+; Store the result into the target stack slot
+
+       ldy     #2
+       sta     (sp),y          ; Store low byte
+       sta     tmp1
+       txa                     ; Get high byte
+       iny
+       sta     (sp),y          ; Store high byte
+
+; Check for a NULL pointer
+
+       ora     tmp1
+       beq     OutOfMemory
+
+; Copy the string. memcpy will return the target string which is exactly
+; what we need here. It will also drop the allocated stack frame.
+
+       lda     ptr4
+       ldx     ptr4+1          ; Load size
+       jmp     _memcpy         ; Copy string, drop stackframe
+
+; Out of memory, return NULL (A = 0)
+
+OutOfMemory:
+       tax
+       jmp     incsp4          ; Drop stack frame
+
+