More reasonable fallback for self path.

* Makefile (opt/txr.o, dbg/txr.o): Set up TXR_REL_PATH
preprocessor symbol on command line which specifies the
hard installation path derived from the configure prefix.

* txr.c (get_self_path): The fallback implementation simply
returns TXR_REL_PATH. This will work if in fact the executable
is installed at that path. What it means is that the build of
TXR which uses this fallback get_self_path will not support
relocation: the installation cannot be moved to another
directory, yet still find its supporting files.  This is
better than what we are replacing: not working even in the
original installation directory, if not invoked by an absolute
path.

2 files changed, 5 insertions, 11 deletions

diff --git a/Makefile b/Makefile
index c9d0f99d..64c2f02a 100644
--- a/Makefile
+++ b/Makefile
@@ -325,9 +325,11 @@ dbg/ffi.o: TXR_CFLAGS += $(LIBFFI_CFLAGS)
 # calculations.
 
 opt/txr.o: TXR_CFLAGS += -DPROG_NAME=\"$(PROG)\" \
-                         -DTXR_REL_PATH=\"$(bindir_rel)/$(PROG)$(EXE)\"
+                         -DTXR_REL_PATH=\"$(bindir_rel)/$(PROG)$(EXE)\" \
+								 -DTXR_INST_PATH=\"$(bindir)/$(PROG)$(EXE)\"
 dbg/txr.o: TXR_CFLAGS += -DPROG_NAME=\"$(PROG)-dbg\" \
-                         -DTXR_REL_PATH=\"$(bindir_rel)/$(PROG)-dbg$(EXE)\"
+                         -DTXR_REL_PATH=\"$(bindir_rel)/$(PROG)-dbg$(EXE)\" \
+								 -DTXR_INST_PATH=\"$(bindir)/$(PROG)$(EXE)\"
 opt/txr-win.o: TXR_CFLAGS += -DPROG_NAME=\"$(PROG)-win\" \
                              -DTXR_REL_PATH=\"$(bindir_rel)/$(PROG)-win$(EXE)\"
 dbg/txr-win.o: TXR_CFLAGS += -DPROG_NAME=\"$(PROG)-win-dbg\" \
diff --git a/txr.c b/txr.c
index 197f6515..a77c53c9 100644
--- a/txr.c
+++ b/txr.c
@@ -254,15 +254,7 @@ static val get_self_path(void)
 #else
 static val get_self_path(void)
 {
-  char self[PATH_MAX];
-
-  if (!progname_u8)
-    return nil;
-
-  if (realpath(progname_u8, self))
-    return string_utf8(self);
-
-  return nil;
+  return lit(TXR_INST_PATH);
 }
 #endif