[libc-commits] [PATCH] D109588: [libc] Check signs instead of values in memcmp unittests.

[Cheng Wang via Phabricator via libc-commits]

cheng.w created this revision.
cheng.w added a reviewer: gchatelet.
Herald added subscribers: libc-commits, ecnelises, tschuett.
Herald added a project: libc-project.
cheng.w requested review of this revision.

The C standard only guarantees the sign of return value. The exact return
value is implementation defined.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109588

Files:
  libc/test/src/string/memcmp_test.cpp


Index: libc/test/src/string/memcmp_test.cpp
===================================================================
--- libc/test/src/string/memcmp_test.cpp
+++ libc/test/src/string/memcmp_test.cpp
@@ -11,7 +11,7 @@
 
 TEST(LlvmLibcMemcmpTest, CmpZeroByte) {
   const char *lhs = "ab";
-  const char *rhs = "bc";
+  const char *rhs = "yz";
   EXPECT_EQ(__llvm_libc::memcmp(lhs, rhs, 0), 0);
 }
 
@@ -23,14 +23,14 @@
 
 TEST(LlvmLibcMemcmpTest, LhsBeforeRhsLexically) {
   const char *lhs = "ab";
-  const char *rhs = "ac";
-  EXPECT_EQ(__llvm_libc::memcmp(lhs, rhs, 2), -1);
+  const char *rhs = "az";
+  EXPECT_LT(__llvm_libc::memcmp(lhs, rhs, 2), 0);
 }
 
 TEST(LlvmLibcMemcmpTest, LhsAfterRhsLexically) {
-  const char *lhs = "ac";
+  const char *lhs = "az";
   const char *rhs = "ab";
-  EXPECT_EQ(__llvm_libc::memcmp(lhs, rhs, 2), 1);
+  EXPECT_GT(__llvm_libc::memcmp(lhs, rhs, 2), 0);
 }
 
 TEST(LlvmLibcMemcmpTest, Sweep) {
@@ -51,8 +51,8 @@
   reset(lhs);
   reset(rhs);
   for (size_t i = 0; i < kMaxSize; ++i) {
-    rhs[i] = 'b';
-    EXPECT_EQ(__llvm_libc::memcmp(lhs, rhs, kMaxSize), -1);
+    rhs[i] = 'z';
+    EXPECT_LT(__llvm_libc::memcmp(lhs, rhs, kMaxSize), 0);
     rhs[i] = 'a';
   }
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D109588.371845.patch
Type: text/x-patch
Size: 1204 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/libc-commits/attachments/20210910/45347483/attachment.bin>