Thomas,
On Sun, Apr 02, 2023 at 01:02:44PM +0000, Thomas Weißschuh wrote:
vfprintf() is complex and so far did not have proper tests.
This series is based on the "dev" branch of the RCU tree.
I've just ran it with glibc to see:
$ gcc nolibc-test.c $ ./a.out vfprintf Running test 'vfprintf' 0 empty "" = "" [OK] 1 simple written(3) != read(0) [FAIL] 2 string written(3) != read(0) [FAIL] 3 number written(4) != read(0) [FAIL] 4 negnumber written(5) != read(0) [FAIL] 5 unsigned written(5) != read(0) [FAIL] 6 char written(1) != read(0) [FAIL] 7 hex written(1) != read(0) [FAIL] 8 pointer written(5) != 3 [FAIL] Errors during this test: 8
The main issue was that glibc uses buffered writes by default.
I could fix them with fflush() (which we don't have so it required an ifndef), and this also made me realize that we were missing an fclose() as well for compatibility with glibc. With this it got better:
Running test 'vfprintf' 0 empty "" = "" [OK] 1 simple "foo" = "foo" [OK] 2 string "foo" = "foo" [OK] 3 number "1234" = "1234" [OK] 4 negnumber "-1234" = "-1234" [OK] 5 unsigned "12345" = "12345" [OK] 6 char "c" = "c" [OK] 7 hex "f" = "f" [OK] 8 pointer written(5) != 3 [FAIL] Errors during this test: 1
This is caused by glibc emitting "(nil)" while we emit "0x0" for a NULL pointer since we use the same code as when dumping integers. I could fix that one as well by printing (void*)1 instead, which shows "0x1" for both.
This gives me the patch below on top of yours, which I think would make sense to integrate in this form or a simplified one if we manage to add fflush() and fclose() earlier.
What do you think ?
Thanks, Willy
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 28a8d77078dc..2958dc3eca93 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -678,6 +678,7 @@ static int expect_vfprintf(int llen, size_t c, const char *expected, const char int ret, fd, w, r; char buf[100]; va_list args; + FILE *memfile;
fd = memfd_create("vfprintf", 0); if (fd == -1) { @@ -685,8 +686,14 @@ static int expect_vfprintf(int llen, size_t c, const char *expected, const char return 1; }
+ memfile = fdopen(fd, "w+"); + if (!memfile) { + pad_spc(llen, 64, "[FAIL]\n"); + return 1; + } + va_start(args, fmt); - w = vfprintf(fdopen(fd, "w+"), fmt, args); + w = vfprintf(memfile, fmt, args); va_end(args);
if (w != c) { @@ -695,12 +702,19 @@ static int expect_vfprintf(int llen, size_t c, const char *expected, const char return 1; }
+#ifndef _NOLIBC_STDIO_H + fflush(memfile); +#endif lseek(fd, 0, SEEK_SET);
r = read(fd, buf, sizeof(buf) - 1); buf[r] = '\0';
+#ifndef _NOLIBC_STDIO_H + fclose(memfile); +#else close(fd); +#endif
if (r != w) { llen += printf(" written(%d) != read(%d)", w, r); @@ -737,7 +751,7 @@ static int run_vfprintf(int min, int max) CASE_TEST(unsigned); EXPECT_VFPRINTF(5, "12345", "%u", 12345); break; CASE_TEST(char); EXPECT_VFPRINTF(1, "c", "%c", 'c'); break; CASE_TEST(hex); EXPECT_VFPRINTF(1, "f", "%x", 0xf); break; - CASE_TEST(pointer); EXPECT_VFPRINTF(3, "0x0", "%p", NULL); break; + CASE_TEST(pointer); EXPECT_VFPRINTF(3, "0x1", "%p", (void*)0x1); break; case __LINE__: return ret; /* must be last */ /* note: do not set any defaults so as to permit holes above */