From 0a468566890696f0864fa224653be8b3e609d47f Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Tue, 19 Jul 2022 09:02:42 +0200
Subject: [PATCH] Squashed 'src/c-stdaux/' changes from
 1407a1fb2754..da7209900ef0

da7209900ef0 api: add c_memcmp()
2369947a563b build: use v1 ci-sphinx
d46a3eeaf30d build: mention documentation in README.md

git-subtree-dir: src/c-stdaux
git-subtree-split: da7209900ef065024db92b180dd8bc70440af9b4
---
 .github/workflows/ci.yml |  2 +-
 README.md                |  1 +
 src/c-stdaux.h           | 17 +++++++++++++++++
 src/test-basic.c         | 11 +++++++++++
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0b905f5683..d35e113865 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,6 +25,6 @@ jobs:
       macos: true
   ci-docs:
     name: Documentation CI
-    uses: bus1/cabuild/.github/workflows/ci-sphinx.yml@main
+    uses: bus1/cabuild/.github/workflows/ci-sphinx.yml@v1
     with:
       source: "./src/docs"
diff --git a/README.md b/README.md
index 124c692e12..d56fbc05c5 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ common extended features of wide-spread compilers like gcc and clang.
 ### Project
 
  * **Website**: <https://c-util.github.io/c-stdaux>
+ * **Documentation**: <https://c-stdaux.readthedocs.io>
  * **Bug Tracker**: <https://github.com/c-util/c-stdaux/issues>
 
 ### Requirements
diff --git a/src/c-stdaux.h b/src/c-stdaux.h
index 6eb0a22d03..f87362bece 100644
--- a/src/c-stdaux.h
+++ b/src/c-stdaux.h
@@ -675,6 +675,23 @@ static inline void *c_memcpy(void *dst, const void *src, size_t n) {
         return dst;
 }
 
+/**
+ * c_memcmp() - Compare memory areas
+ * @s1:         Pointer to one area
+ * @s2:         Pointer to other area
+ * @n:          Length of area to compare
+ *
+ * Compare the memory of size ``n`` of ``s1`` and ``s2``, just as ``memcmp(3)``
+ * does, except this function allows either to be ``NULL`` if ``n`` is zero.
+ *
+ * Return: Comparison result for ordering is returned.
+ */
+static inline int c_memcmp(const void *s1, const void *s2, size_t n) {
+        if (n > 0)
+                return memcmp(s1, s2, n);
+        return 0;
+}
+
 /**
  * DOC: Common Destructors
  *
diff --git a/src/test-basic.c b/src/test-basic.c
index e5e3f907ed..28eb458973 100644
--- a/src/test-basic.c
+++ b/src/test-basic.c
@@ -357,6 +357,17 @@ static void test_misc(int non_constant_expr) {
 
                 c_memcpy(NULL, NULL, 0);
         }
+
+        /*
+         * Test c_memcmp() with.
+         */
+        {
+                uint64_t v1 = (uint64_t)-1, v2 = (uint64_t)0;
+
+                c_assert(c_memcmp(NULL, NULL, 0) == 0);
+                c_assert(c_memcmp(&v1, &v2, 0) == 0);
+                c_assert(c_memcmp(&v1, &v2, 8) != 0);
+        }
 }
 
 /*