Unverified Commit 3b53e7f8 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!13450 [OLK-6.6][Backport] tools/nolibc: add support for constructors and destructors 

Merge Pull Request from: @lazy2528 
 
With the startup code moved to C, implementing support for
constructors and deconstructors is fairly easy to implement.

Examples for code size impact:

   text	   data	    bss	    dec	    hex	filename
  21837	    104	     88	  22029	   560d	nolibc-test.before
  22135	    120	     88	  22343	   5747	nolibc-test.after
  21970	    104	     88	  22162	   5692 nolibc-test.after-only-crt.h-changes

The sections are defined by [0].

[0] https://refspecs.linuxfoundation.org/elf/gabi4+/ch5.dynamic.html

#IB6FDC  
 
Link:https://gitee.com/openeuler/kernel/pulls/13450
parents 01b9dbc5 86a3597c

tools/include/nolibc/crt.h

+22 −1
Original line number Diff line number Diff line
@@ -13,12 +13,23 @@ const unsigned long *_auxv __attribute__((weak)); 
static void __stack_chk_init(void);

static void exit(int);



extern void (*const __preinit_array_start[])(void) __attribute__((weak));

extern void (*const __preinit_array_end[])(void) __attribute__((weak));



extern void (*const __init_array_start[])(void) __attribute__((weak));

extern void (*const __init_array_end[])(void) __attribute__((weak));



extern void (*const __fini_array_start[])(void) __attribute__((weak));

extern void (*const __fini_array_end[])(void) __attribute__((weak));



__attribute__((weak))

void _start_c(long *sp)

{

	long argc;

	char **argv;

	char **envp;

	int exitcode;

	void (* const *func)(void);

	const unsigned long *auxv;

	/* silence potential warning: conflicting types for 'main' */

	int _nolibc_main(int, char **, char **) __asm__ ("main");
@@ -55,8 +66,18 @@ void _start_c(long *sp) 
		;

	_auxv = auxv;



	for (func = __preinit_array_start; func < __preinit_array_end; func++)

		(*func)();

	for (func = __init_array_start; func < __init_array_end; func++)

		(*func)();



	/* go to application */

	exit(_nolibc_main(argc, argv, envp));

	exitcode = _nolibc_main(argc, argv, envp);



	for (func = __fini_array_end; func > __fini_array_start;)

		(*--func)();



	exit(exitcode);

}



#endif /* _NOLIBC_CRT_H */

tools/testing/selftests/nolibc/nolibc-test.c

+17 −0
Original line number Diff line number Diff line
@@ -57,6 +57,9 @@ static int test_argc; 
/* will be used by some test cases as readable file, please don't write it */

static const char *argv0;



/* will be used by constructor tests */

static int constructor_test_value;



/* definition of a series of tests */

struct test {

	const char *name;              /* test name */
@@ -594,6 +597,19 @@ int expect_strne(const char *expr, int llen, const char *cmp) 
#define CASE_TEST(name) \

	case __LINE__: llen += printf("%d %s", test, #name);



/* constructors validate that they are executed in definition order */

__attribute__((constructor))

static void constructor1(void)

{

	constructor_test_value = 1;

}



__attribute__((constructor))

static void constructor2(void)

{

	constructor_test_value *= 2;

}



int run_startup(int min, int max)

{

	int test;
@@ -630,6 +646,7 @@ int run_startup(int min, int max) 
		CASE_TEST(environ_HOME);     EXPECT_PTRNZ(1, getenv("HOME")); break;

		CASE_TEST(auxv_addr);        EXPECT_PTRGT(test_auxv != (void *)-1, test_auxv, brk); break;

		CASE_TEST(auxv_AT_UID);      EXPECT_EQ(1, getauxval(AT_UID), getuid()); break;

		CASE_TEST(constructor);      EXPECT_EQ(1, constructor_test_value, 2); break;

		CASE_TEST(auxv_AT_PAGESZ);   EXPECT_GE(1, getauxval(AT_PAGESZ), 4096); break;

		case __LINE__:

			return ret; /* must be last */