Some compatibility improvements for older (C89) environments

Whether this actually works on older environments, I don't really know.

Makefile.am

@@ -45,6 +45,8 @@ EXTRA_DIST=ncdu.1 doc/ncdu.pod
 ncdu.1: $(srcdir)/doc/ncdu.pod
 	pod2man --center "ncdu manual" --release "@PACKAGE@-@VERSION@" "$(srcdir)/doc/ncdu.pod" >ncdu.1
 
+# This target exists more for documentation purposes than actual use; some
+# dependencies have minor ncdu-specific changes.
 update-deps:
 	wget -q https://raw.github.com/attractivechaos/klib/master/khashl.h -O "$(srcdir)/deps/khashl.h"
 	wget -q http://g.blicky.net/ylib.git/plain/yopt.h -O "$(srcdir)/deps/yopt.h"

configure.ac

@@ -1,10 +1,11 @@
 
 AC_INIT([ncdu],[1.16],[projects@yorhel.nl])
 AC_CONFIG_SRCDIR([src/global.h])
-AC_CONFIG_HEADER([config.h])
+AC_CONFIG_HEADERS([config.h])
 AM_INIT_AUTOMAKE([foreign std-options subdir-objects])
 
 # Check for programs.
+AC_USE_SYSTEM_EXTENSIONS
 AC_PROG_CC
 AC_PROG_INSTALL
 AC_PROG_RANLIB
@@ -22,6 +23,8 @@ AC_TYPE_INT64_T
 AC_TYPE_UINT64_T
 AC_SYS_LARGEFILE
 AC_STRUCT_ST_BLOCKS
+AC_C_INLINE
+AC_C_FLEXIBLE_ARRAY_MEMBER
 
 # Check for library functions.
 AC_CHECK_FUNCS(

deps/strnatcmp.c

@@ -28,35 +28,22 @@
  * Eric Sosman pointed out that ctype functions take a parameter whose
  * value must be that of an unsigned int, even on platforms that have
  * negative chars in their default char type.
+ *
+ * ncdu edits:
+ * - static inline -> #define for better compatibility
+ * - don't use ctype.h, for more predictable results
  */
 
 #include <stddef.h>	/* size_t */
-#include <ctype.h>
 
 #include "strnatcmp.h"
 
 
 /* These are defined as macros to make it easier to adapt this code to
  * different characters types or comparison functions. */
-static inline int
-nat_isdigit(nat_char a)
-{
-     return isdigit((unsigned char) a);
-}
-
-
-static inline int
-nat_isspace(nat_char a)
-{
-     return isspace((unsigned char) a);
-}
-
-
-static inline nat_char
-nat_toupper(nat_char a)
-{
-     return toupper((unsigned char) a);
-}
+#define nat_isdigit(a) ((a) >= '0' && (a) <= '9')
+#define nat_isspace(a) ((a) == ' ' || (a) == '\t' || (a) == '\r' || (a) == '\n')
+#define nat_toupper(a) (a)
 
 
 static int

src/dir_import.c

@@ -465,7 +465,7 @@ static int iteminfo(void) {
       C(rint64(&iv, UINT64_MAX));
       ctx->buf_dir->flags |= FF_EXT;
       ctx->buf_ext->mtime = iv;
-      // Accept decimal numbers, but discard the fractional part because our data model doesn't support it.
+      /* Accept decimal numbers, but discard the fractional part because our data model doesn't support it. */
       if(*ctx->buf == '.') {
           con(1);
           while(*ctx->buf >= '0' && *ctx->buf <= '9')

src/dir_mem.c

@@ -127,7 +127,7 @@ static int item(struct dir *dir, const char *name, struct dir_ext *ext, unsigned
   item = xmalloc(dir->flags & FF_EXT ? dir_ext_memsize(name) : dir_memsize(name));
   memcpy(item, dir, offsetof(struct dir, name));
   strcpy(item->name, name);
-  if(dir->flags & FF_EXT)
+  if(item->flags & FF_EXT)
     memcpy(dir_ext_ptr(item), ext, sizeof(struct dir_ext));
 
   item_add(item);

src/global.h

@@ -70,7 +70,7 @@ struct dir {
   struct dir *parent, *next, *prev, *sub, *hlnk;
   int items;
   unsigned short flags;
-  char name[];
+  char name[FLEXIBLE_ARRAY_MEMBER];
 };
 
 /* A note on the ino and dev fields above: ino is usually represented as ino_t,

src/shell.c

@@ -40,7 +40,7 @@ static void set_level(void) {
   if(done)
     return;
   const char *lvl = getenv("NCDU_LEVEL");
-  // too lazy to count beyond 9
+  /* too lazy to count beyond 9 */
   if(lvl && *lvl >= '1' && *lvl < '9' && lvl[1] == 0) {
     nlvl[0] = 1 + *lvl;
     nlvl[1] = 0;

src/util.h

@@ -73,17 +73,12 @@ extern int subwinr, subwinc;
 extern int si;
 
 
-/* Macros/functions for managing struct dir and struct dir_ext */
+/* Macros for managing struct dir and struct dir_ext */
 
 #define dir_memsize(n)     (offsetof(struct dir, name)+1+strlen(n))
 #define dir_ext_offset(n)  ((dir_memsize(n) + 7) & ~7)
 #define dir_ext_memsize(n) (dir_ext_offset(n) + sizeof(struct dir_ext))
-
-static inline struct dir_ext *dir_ext_ptr(struct dir *d) {
-  return d->flags & FF_EXT
-    ? (struct dir_ext *) ( ((char *)d) + dir_ext_offset(d->name) )
-    : NULL;
-}
+#define dir_ext_ptr(d)     ((d)->flags & FF_EXT ? (struct dir_ext *) ( ((char *)(d)) + dir_ext_offset((d)->name) ) : NULL)
 
 
 /* Instead of using several ncurses windows, we only draw to stdscr.