add fix for gcc 9.1 in the makefile, don't accept LTO input files

Makefile

@@ -58,6 +58,12 @@ clean:
 %/:
 	@mkdir -vp "$@"
 
+ifneq ($(findstring (GCC) 9,$(shell $(CC) --version)),)
+INCLINKOPT := -flinker-output=nolto-rel
+else
+INCLINKOPT :=
+endif
+
 .SECONDARY:
 
 $(OBJDIR)/%.lto.o: $(SRCDIR)/%.c $(OBJDIR)/
@@ -71,7 +77,7 @@ $(OBJDIR)/%.o: $(TESTDIR)/%.c $(OBJDIR)/
 	$(CC) $(CFLAGS) -c "$<" -o "$@"
 
 $(OBJDIR)/%.start.o: $(OBJDIR)/%.lto.o $(OBJDIR)/crt1.lto.o
-	$(CC) $(LDFLAGS) -r -o "$@" $^
+	$(CC) $(LDFLAGS) -r $(INCLINKOPT) -o "$@" $^
 
 $(OBJDIR)/symbols.%.asm: $(OBJDIR)/%.o
 	$(PYTHON3) $(PYDIR)/smol.py $(SMOLFLAGS) $(LIBS) "$<" "$@"

src/smolparse.py

@@ -56,10 +56,16 @@ def get_needed_syms(readelf_bin, inpfiles):
 
     relocs = build_reloc_typ_table(outrel)
 
+    curfile = inpfiles[0]
     syms=set({})
     for entry in output.decode('utf-8').splitlines():
         stuff = entry.split()
+        if len(stuff)<2: continue
+        if stuff[0] == "File:": curfile = stuff[1]
         if len(stuff)<8: continue
+        if stuff[7].startswith("__gnu_lto_"): # yikes, an LTO object
+            eprintf("{} is an LTO object file, can't use this!".format(curfile))
+            exit(1)
         if stuff[4] == "GLOBAL" and stuff[6] == "UND" and len(stuff[7])>0 \
                 and stuff[7] in relocs:
             syms.add((stuff[7], relocs[stuff[7]]))