FileCheck: Document CHECK-SAME, follow-up to r230612
llvm-svn: 231379
diff --git a/llvm/docs/CommandGuide/FileCheck.rst b/llvm/docs/CommandGuide/FileCheck.rst
index af01503..72db660 100644
--- a/llvm/docs/CommandGuide/FileCheck.rst
+++ b/llvm/docs/CommandGuide/FileCheck.rst
@@ -185,6 +185,31 @@
newline between it and the previous directive. A "``CHECK-NEXT:``" cannot be
the first directive in a file.
+The "CHECK-SAME:" directive
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Sometimes you want to match lines and would like to verify that matches happen
+on the same line as the previous match. In this case, you can use "``CHECK:``"
+and "``CHECK-SAME:``" directives to specify this. If you specified a custom
+check prefix, just use "``<PREFIX>-SAME:``".
+
+"``CHECK-SAME:``" is particularly powerful in conjunction with "``CHECK-NOT:``"
+(described below).
+
+For example, the following works like you'd expect:
+
+.. code-block:: llvm
+
+ !0 = !MDLocation(line: 5, scope: !1, inlinedAt: !2)
+
+ ; CHECK: !MDLocation(line: 5,
+ ; CHECK-NOT: column:
+ ; CHECK-SAME: scope: ![[SCOPE:[0-9]+]]
+
+"``CHECK-SAME:``" directives reject the input if there are any newlines between
+it and the previous directive. A "``CHECK-SAME:``" cannot be the first
+directive in a file.
+
The "CHECK-NOT:" directive
~~~~~~~~~~~~~~~~~~~~~~~~~~