git: b166580681e3 - main - lib/libc/tests/string/memcmp_test.c: extend test to support custom memcmp function

The branch main has been updated by fuz:

URL: https://cgit.FreeBSD.org/src/commit/?id=b166580681e3af173ec368656019d02ba1cc55ad

commit b166580681e3af173ec368656019d02ba1cc55ad
Author:     Robert Clausecker <fuz@FreeBSD.org>
AuthorDate: 2023-07-14 11:56:12 +0000
Commit:     Robert Clausecker <fuz@FreeBSD.org>
CommitDate: 2023-10-02 19:25:21 +0000

    lib/libc/tests/string/memcmp_test.c: extend test to support custom memcmp function
    
    Extend the tests to permit loading an external memcmp function
    and testing it over using the libc version. This was added by the
    example of other tests in the test suite doing the same thing and
    helped tremendously in development.
    
    This change was originally part of D41442 but was taken out to
    permit separate review as extrapolated from @ngie's request in
    D41349.
    
    Sponsored by:   FreeBSD Foundation
    Approved by:    ngie
    Differential Revision:  https://reviews.freebsd.org/D41528
---
 lib/libc/tests/string/memcmp_test.c | 57 +++++++++++++++++++++----------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/lib/libc/tests/string/memcmp_test.c b/lib/libc/tests/string/memcmp_test.c
index ab782c92f255..f42bccfca529 100644
--- a/lib/libc/tests/string/memcmp_test.c
+++ b/lib/libc/tests/string/memcmp_test.c
@@ -26,18 +26,21 @@
 
 #include <sys/cdefs.h>
 #include <assert.h>
+#include <dlfcn.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <atf-c.h>
 
+static int (*memcmp_fn)(const void *, const void *, size_t);
+
 ATF_TC_WITHOUT_HEAD(zero);
 ATF_TC_BODY(zero, tc)
 {
 
-	assert(memcmp("a", "b", 0) == 0);
-	assert(memcmp("", "", 0) == 0);
+	assert(memcmp_fn("a", "b", 0) == 0);
+	assert(memcmp_fn("", "", 0) == 0);
 }
 
 ATF_TC_WITHOUT_HEAD(eq);
@@ -49,9 +52,9 @@ ATF_TC_BODY(eq, tc)
 	for (i = 0; i < 256; i++)
 		data1[i] = data2[i] = i ^ 0x55;
 	for (i = 1; i < 256; i++)
-		assert(memcmp(data1, data2, i) == 0);
+		assert(memcmp_fn(data1, data2, i) == 0);
 	for (i = 1; i < 256; i++)
-		assert(memcmp(data1 + i, data2 + i, 256 - i) == 0);
+		assert(memcmp_fn(data1 + i, data2 + i, 256 - i) == 0);
 }
 
 ATF_TC_WITHOUT_HEAD(neq);
@@ -65,9 +68,9 @@ ATF_TC_BODY(neq, tc)
 		data2[i] = i ^ 0x55;
 	}
 	for (i = 1; i < 256; i++)
-		assert(memcmp(data1, data2, i) != 0);
+		assert(memcmp_fn(data1, data2, i) != 0);
 	for (i = 1; i < 256; i++)
-		assert(memcmp(data1 + i, data2 + i, 256 - i) != 0);
+		assert(memcmp_fn(data1 + i, data2 + i, 256 - i) != 0);
 }
 
 ATF_TC_WITHOUT_HEAD(diff);
@@ -81,37 +84,43 @@ ATF_TC_BODY(diff, tc)
 	data1[128] = 255;
 	data2[128] = 0;
 	for (i = 1; i < 66; i++) {
-		assert(memcmp(data1 + 128, data2 + 128, i) == 255);
-		assert(memcmp(data2 + 128, data1 + 128, i) == -255);
-		assert(memcmp(data1 + 129 - i, data2 + 129 - i, i) == 255);
-		assert(memcmp(data2 + 129 - i, data1 + 129 - i, i) == -255);
-		assert(memcmp(data1 + 129 - i, data2 + 129 - i, i * 2) == 255);
-		assert(memcmp(data2 + 129 - i, data1 + 129 - i, i * 2) == -255);
+		assert(memcmp_fn(data1 + 128, data2 + 128, i) == 255);
+		assert(memcmp_fn(data2 + 128, data1 + 128, i) == -255);
+		assert(memcmp_fn(data1 + 129 - i, data2 + 129 - i, i) == 255);
+		assert(memcmp_fn(data2 + 129 - i, data1 + 129 - i, i) == -255);
+		assert(memcmp_fn(data1 + 129 - i, data2 + 129 - i, i * 2) == 255);
+		assert(memcmp_fn(data2 + 129 - i, data1 + 129 - i, i * 2) == -255);
 	}
 	data1[128] = 'c';
 	data2[128] = 'e';
 	for (i = 1; i < 66; i++) {
-		assert(memcmp(data1 + 128, data2 + 128, i) == -2);
-		assert(memcmp(data2 + 128, data1 + 128, i) == 2);
-		assert(memcmp(data1 + 129 - i, data2 + 129 - i, i) == -2);
-		assert(memcmp(data2 + 129 - i, data1 + 129 - i, i) == 2);
-		assert(memcmp(data1 + 129 - i, data2 + 129 - i, i * 2) == -2);
-		assert(memcmp(data2 + 129 - i, data1 + 129 - i, i * 2) == 2);
+		assert(memcmp_fn(data1 + 128, data2 + 128, i) == -2);
+		assert(memcmp_fn(data2 + 128, data1 + 128, i) == 2);
+		assert(memcmp_fn(data1 + 129 - i, data2 + 129 - i, i) == -2);
+		assert(memcmp_fn(data2 + 129 - i, data1 + 129 - i, i) == 2);
+		assert(memcmp_fn(data1 + 129 - i, data2 + 129 - i, i * 2) == -2);
+		assert(memcmp_fn(data2 + 129 - i, data1 + 129 - i, i * 2) == 2);
 	}
 	memset(data1 + 129, 'A', sizeof(data1) - 129);
 	memset(data2 + 129, 'Z', sizeof(data2) - 129);
 	for (i = 1; i < 66; i++) {
-		assert(memcmp(data1 + 128, data2 + 128, i) == -2);
-		assert(memcmp(data2 + 128, data1 + 128, i) == 2);
-		assert(memcmp(data1 + 129 - i, data2 + 129 - i, i) == -2);
-		assert(memcmp(data2 + 129 - i, data1 + 129 - i, i) == 2);
-		assert(memcmp(data1 + 129 - i, data2 + 129 - i, i * 2) == -2);
-		assert(memcmp(data2 + 129 - i, data1 + 129 - i, i * 2) == 2);
+		assert(memcmp_fn(data1 + 128, data2 + 128, i) == -2);
+		assert(memcmp_fn(data2 + 128, data1 + 128, i) == 2);
+		assert(memcmp_fn(data1 + 129 - i, data2 + 129 - i, i) == -2);
+		assert(memcmp_fn(data2 + 129 - i, data1 + 129 - i, i) == 2);
+		assert(memcmp_fn(data1 + 129 - i, data2 + 129 - i, i * 2) == -2);
+		assert(memcmp_fn(data2 + 129 - i, data1 + 129 - i, i * 2) == 2);
 	}
 }
 
 ATF_TP_ADD_TCS(tp)
 {
+	void *dl_handle;
+
+	dl_handle = dlopen(NULL, RTLD_LAZY);
+	memcmp_fn = dlsym(dl_handle, "test_memcmp");
+	if (memcmp_fn == NULL)
+		memcmp_fn = memcmp;
 
 	ATF_TP_ADD_TC(tp, zero);
 	ATF_TP_ADD_TC(tp, eq);