Added ABI compatibility tests with native compiler using libtcc.

Only one test so far, which fails on Windows (with MinGW as the native
compiler - I've tested the MinGW output against MSVC and it appears the
two are compatible).

I've also had to modify tcc.h so that tcc_set_lib_path can point to the
directory containing libtcc1.a on Windows to make the libtcc dependent
tests work. I'm not sure this is the right way to fix this problem.

tcc.h

@@ -191,7 +191,7 @@
 /* library search paths */
 #ifndef CONFIG_TCC_LIBPATHS
 # ifdef TCC_TARGET_PE
-#  define CONFIG_TCC_LIBPATHS "{B}/lib"
+#  define CONFIG_TCC_LIBPATHS "{B}/lib;{B}"
 # else
 #  define CONFIG_TCC_LIBPATHS \
         CONFIG_SYSROOT "/usr/" CONFIG_LDDIR \

tests/Makefile

@@ -13,6 +13,7 @@ TESTS = \
  hello-run \
  libtest \
  test3 \
+ abitest-exe \
  moretests
 
 # test4 -- problem with -static
@@ -177,6 +178,15 @@ asmtest: asmtest.ref
 	objdump -D asmtest.o > asmtest.out
 	@if diff -u --ignore-matching-lines="file format" asmtest.ref asmtest.out ; then echo "ASM Auto Test OK"; fi
 
+# Check that code generated by libtcc is binary compatible with
+# that generated by CC
+abitest$(EXESUF): abitest.c $(top_builddir)/$(LIBTCC)
+	$(CC) -o $@ $^ $(CPPFLAGS) $(CFLAGS) $(NATIVE_DEFINES) $(LIBS) $(LINK_LIBTCC) $(LDFLAGS) -I$(top_srcdir) -g -O0
+
+abitest-exe: abitest$(EXESUF)
+	@echo ------------ $@ ------------
+	abitest$(EXESUF) lib_path=..
+
 # targets for development
 %.bin: %.c tcc
 	$(TCC) -g -o $@ $<

tests/abitest.c

@@ -0,0 +1,80 @@
+#include <libtcc.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+static const char *tccdir = NULL;
+
+typedef int (*callback_type) (void*);
+
+/*
+ * Compile source code and call a callback with a pointer to the symbol "f".
+ */
+static int run_callback(const char *src, callback_type callback) {
+  TCCState *s;
+  int result;
+  void *ptr;
+  
+  s = tcc_new();
+  if (!s)
+    return -1;
+  if (tccdir)
+    tcc_set_lib_path(s, tccdir);
+  if (tcc_set_output_type(s, TCC_OUTPUT_MEMORY) == -1)
+    return -1;
+  if (tcc_compile_string(s, src) == -1)
+    return -1;
+  if (tcc_relocate(s, TCC_RELOCATE_AUTO) == -1)
+    return -1;
+  
+  ptr = tcc_get_symbol(s, "f");
+  if (!ptr)
+    return -1;
+  result = callback(ptr);
+  
+  tcc_delete(s);
+  
+  return result;
+}
+
+typedef struct test1_type_s {int x, y;} test1_type;
+typedef test1_type (*test1_function_type) ();
+
+static int test1_callback(void *ptr) {
+  test1_type r;
+  r  = ((test1_function_type)ptr)();
+  return ((r.x == 10) && (r.y == 35)) ? 0 : -1;
+}
+
+static int test1() {
+  const char *src =
+  "typedef struct test1_type_s {int x, y;} test1_type;"
+  "test1_type f() {\n"
+  "  test1_type r = {10, 35};\n"
+  "  return r;\n"
+  "}\n";
+  
+  return run_callback(src, test1_callback);
+}
+
+#define RUN_TEST(t) \
+  do { \
+    fputs(#t "... ", stdout); \
+    fflush(stdout); \
+    if (t() == 0) { \
+      fputs("success\n", stdout); \
+    } else { \
+      fputs("failure\n", stdout); \
+      retval = EXIT_FAILURE; \
+    } \
+  } while (0);
+
+int main(int argc, char **argv) {
+  int retval = EXIT_SUCCESS;
+  /* if tcclib.h and libtcc1.a are not installed, where can we find them */
+  if (argc == 2 && !memcmp(argv[1], "lib_path=",9))
+    tccdir = argv[1] + 9;
+  
+  RUN_TEST(test1);
+  return retval;
+}