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[libc] Add `IN6_IS_ADDR_MULTICAST`

Open c8ef opened this issue 4 months ago • 2 comments

c8ef avatar Dec 16 '25 15:12 c8ef

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c8ef avatar Dec 16 '25 15:12 c8ef

@llvm/pr-subscribers-libc

Author: Connector Switch (c8ef)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/172498.diff

2 Files Affected:

  • (modified) libc/include/llvm-libc-macros/netinet-in-macros.h (+3)
  • (modified) libc/test/include/netinet_in_test.cpp (+5)
diff --git a/libc/include/llvm-libc-macros/netinet-in-macros.h b/libc/include/llvm-libc-macros/netinet-in-macros.h
index 3148aed6bb112..863ff8759e446 100644
--- a/libc/include/llvm-libc-macros/netinet-in-macros.h
+++ b/libc/include/llvm-libc-macros/netinet-in-macros.h
@@ -53,6 +53,9 @@
    (__LLVM_LIBC_CAST(reinterpret_cast, uint8_t *, a)[14]) == 0 &&              \
    (__LLVM_LIBC_CAST(reinterpret_cast, uint8_t *, a)[15]) == 1)
 
+#define IN6_IS_ADDR_MULTICAST(a)                                               \
+  (__LLVM_LIBC_CAST(reinterpret_cast, uint8_t *, a)[0]) == 0xff
+
 #define IN6_IS_ADDR_LINKLOCAL(a)                                               \
   ((__LLVM_LIBC_CAST(reinterpret_cast, uint8_t *, a)[0]) == 0xfe &&            \
    (__LLVM_LIBC_CAST(reinterpret_cast, uint8_t *, a)[1] & 0xc0) == 0x80)
diff --git a/libc/test/include/netinet_in_test.cpp b/libc/test/include/netinet_in_test.cpp
index 15e57ccef7ac5..e8cb8e48ff4b4 100644
--- a/libc/test/include/netinet_in_test.cpp
+++ b/libc/test/include/netinet_in_test.cpp
@@ -24,6 +24,11 @@ TEST(LlvmLibcNetinetInTest, IN6Macro) {
   EXPECT_TRUE(IN6_IS_ADDR_LOOPBACK(buff));
   buff[15] = 0;
 
+  EXPECT_FALSE(IN6_IS_ADDR_MULTICAST(buff));
+  buff[0] = 0xff;
+  EXPECT_TRUE(IN6_IS_ADDR_MULTICAST(buff));
+  buff[0] = 0;
+
   buff[0] = 0xfe;
   buff[1] = 0x80;
   EXPECT_TRUE(IN6_IS_ADDR_LINKLOCAL(buff));

llvmbot avatar Dec 16 '25 15:12 llvmbot

Merge activity

  • Dec 18, 3:02 PM UTC: A user started a stack merge that includes this pull request via Graphite.

c8ef avatar Dec 18 '25 15:12 c8ef