Allow testsuite to be build with CC -fsanitize

Makefile: Add sani-test* targets + help
tcc.h: redefine offsetof for clang -fsanitize
tccelf.c: section_ptr_add: allow clang -fsanitize
          tcc_add_btstub/tcc_load_object_file: revert previous change.
tccpp.c: Fix -fsanitize problem by casting to unsigned.
tests/Makefile: tcc -v leaks memory (a lot of returns in main() leak memory)
tests/tests2/Makefile: testcase 112 aborts and leaks memory. Disable leak test.

Author: hermantb

Makefile

@@ -467,12 +467,17 @@ tcov-tes% : tcc_c$(EXESUF)
 	@$(MAKE) --no-print-directory TCC_LOCAL=$(CURDIR)/$< tes$*
 tcc_c$(EXESUF): $($T_FILES)
 	$S$(TCC) tcc.c -o $@ -ftest-coverage $(DEFINES) $(LIBS)
+# run tests with sanitize option
+sani-tes% : tcc_s$(EXESUF)
+	@$(MAKE) --no-print-directory TCC_LOCAL=$(CURDIR)/$< tes$*
+tcc_s$(EXESUF): $($T_FILES)
+	$S$(CC) tcc.c -o $@ -fsanitize=address,undefined $(DEFINES) $(CFLAGS) $(LIBS)
 # test the installed tcc instead
 test-install: $(TCCDEFS_H)
 	@$(MAKE) -C tests TESTINSTALL=yes #_all
 
 clean:
-	@rm -f tcc *-tcc tcc_p tcc_c
+	@rm -f tcc *-tcc tcc_p tcc_c tcc_s
 	@rm -f tags ETAGS *.o *.a *.so* *.out *.log lib*.def *.exe *.dll
 	@rm -f a.out *.dylib *_.h *.pod *.tcov
 	@$(MAKE) -s -C lib $@
@@ -501,8 +506,10 @@ help:
 	@echo "   run all/single test(s) from tests2, optionally update .expect"
 	@echo "make testspp.all / make testspp.17"
 	@echo "   run all/single test(s) from tests/pp"
-	@echo "make tcov-test / tcov-tests2... / tcov-testspp..."
+	@echo "make tcov-test / tcov-tests2.37 / tcov-testspp.17"
 	@echo "   run tests as above with code coverage. After test(s) see tcc_c$(EXESUF).tcov"
+	@echo "make sani-test / sani-tests2.37 / sani-testspp.17"
+	@echo "   run tests as above with sanitize option."
 	@echo "make test-install"
 	@echo "   run tests with the installed tcc"
 	@echo "Other supported make targets:"

tcc.h

@@ -99,6 +99,11 @@ extern long double strtold (const char *__nptr, char **__endptr);
 #define offsetof(type, field) ((size_t) &((type *)0)->field)
 #endif
 
+#ifdef __clang__ // clang -fsanitize compains about: NULL+value
+#undef offsetof
+#define offsetof(type, field) __builtin_offsetof(type, field)
+#endif
+
 #ifndef countof
 #define countof(tab) (sizeof(tab) / sizeof((tab)[0]))
 #endif

tccelf.c

@@ -318,7 +318,8 @@ ST_FUNC size_t section_add(Section *sec, addr_t size, int align)
 ST_FUNC void *section_ptr_add(Section *sec, addr_t size)
 {
     size_t offset = section_add(sec, size, 1);
-    return sec->data + offset;
+    // clang -fsanitize compains about: NULL+value
+    return sec->data ? sec->data + offset : (void *)offset;
 }
 
 #ifndef ELF_OBJ_ONLY
@@ -1597,8 +1598,7 @@ ST_FUNC void tcc_add_btstub(TCCState *s1)
 
     s = data_section;
     /* Align to PTR_SIZE */
-    if (s->data_offset)
-        section_ptr_add(s, -s->data_offset & (PTR_SIZE - 1));
+    section_ptr_add(s, -s->data_offset & (PTR_SIZE - 1));
     o = s->data_offset;
     /* create a struct rt_context (see tccrun.c) */
     if (s1->dwarf) {
@@ -3260,7 +3260,7 @@ ST_FUNC int tcc_load_object_file(TCCState *s1,
         sm_table[i].s = s;
         /* concatenate sections */
         size = sh->sh_size;
-        if (sh->sh_type != SHT_NOBITS && size) {
+        if (sh->sh_type != SHT_NOBITS) {
             unsigned char *ptr;
             lseek(fd, file_offset + sh->sh_offset, SEEK_SET);
             ptr = section_ptr_add(s, size);

tccpp.c

@@ -2055,7 +2055,7 @@ static void parse_escape_string(CString *outstr, const uint8_t *buf, int is_long
                         expect("more hex digits in universal-character-name");
                     else
                         goto add_hex_or_ucn;
-                    n = n * 16 + c;
+                    n = (unsigned) n * 16 + c;
                     p++;
                 } while (--i);
 		if (is_long) {

tests/Makefile

@@ -79,7 +79,7 @@ endif
 
 all test :
 	@echo ------------ version ------------
-	@$(TCC_LOCAL) -v
+	@ASAN_OPTIONS=detect_leaks=0 $(TCC_LOCAL) -v
 	@$(MAKE) --no-print-directory -s clean
 	@$(MAKE) --no-print-directory -s -r _all
 

tests/tests2/Makefile

@@ -102,6 +102,7 @@ GEN-ALWAYS =
 112_backtrace.test 113_btdll.test 126_bound_global.test: FILTER += \
     -e 's;[0-9A-Fa-fx]\{5,\};........;g' \
     -e 's;0x[0-9A-Fa-f]\{1,\};0x?;g'
+112_backtrace.test: LEAK=ASAN_OPTIONS=detect_leaks=0
 
 # this test creates two DLLs and an EXE
 113_btdll.test: T1 = \
@@ -136,7 +137,7 @@ all test tests2.all: $(filter-out $(SKIP),$(TESTS))
 	@echo Test: $*...
 	@$(call T1,$<) $(T3)
 
-T1 = $(TCC) $(FLAGS) $(T2) $(ARGS)
+T1 = $(LEAK) $(TCC) $(FLAGS) $(T2) $(ARGS)
 T2 = $(if $(NORUN),$1 -o $(basename $@).exe && ./$(basename $@).exe,-run $1)
 T3 = $(FILTER) >$*.output 2>&1 || true \
      && diff -Nbu $(filter %.expect,$^) $*.output \