vendor/llvm/llvm-trunk-r338150

1 files changed, 59 insertions, 0 deletions

diff --git a/docs/CommandGuide/FileCheck.rst b/docs/CommandGuide/FileCheck.rst
index 9078f65e01c5..b0324f40463d 100644
--- a/docs/CommandGuide/FileCheck.rst
+++ b/docs/CommandGuide/FileCheck.rst
@@ -77,6 +77,10 @@ OPTIONS
   -verify``. With this option FileCheck will verify that input does not contain
   warnings not covered by any ``CHECK:`` patterns.
 
+.. option:: --dump-input-on-failure
+
+  When the check fails, dump all of the original input.
+
 .. option:: --enable-var-scope
 
   Enables scope for regex variables.
@@ -95,6 +99,23 @@ OPTIONS
 
  Show the version number of this program.
 
+.. option:: -v
+
+  Print directive pattern matches.
+
+.. option:: -vv
+
+  Print information helpful in diagnosing internal FileCheck issues, such as
+  discarded overlapping ``CHECK-DAG:`` matches, implicit EOF pattern matches,
+  and ``CHECK-NOT:`` patterns that do not have matches.  Implies ``-v``.
+
+.. option:: --allow-deprecated-dag-overlap
+
+  Enable overlapping among matches in a group of consecutive ``CHECK-DAG:``
+  directives.  This option is deprecated and is only provided for convenience
+  as old tests are migrated to the new non-overlapping ``CHECK-DAG:``
+  implementation.
+
 EXIT STATUS
 -----------
 
@@ -241,6 +262,25 @@ For example, the following works like you'd expect:
 it and the previous directive.  A "``CHECK-SAME:``" cannot be the first
 directive in a file.
 
+The "CHECK-EMPTY:" directive
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you need to check that the next line has nothing on it, not even whitespace,
+you can use the "``CHECK-EMPTY:``" directive.
+
+.. code-block:: llvm
+
+   foo
+
+   bar
+   ; CHECK: foo
+   ; CHECK-EMPTY:
+   ; CHECK-NEXT: bar
+
+Just like "``CHECK-NEXT:``" the directive will fail if there is more than one
+newline before it finds the next blank line, and it cannot be the first
+directive in a file.
+
 The "CHECK-NOT:" directive
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -341,6 +381,25 @@ real bugs away.
 
 In those cases, to enforce the order, use a non-DAG directive between DAG-blocks.
 
+A ``CHECK-DAG:`` directive skips matches that overlap the matches of any
+preceding ``CHECK-DAG:`` directives in the same ``CHECK-DAG:`` block.  Not only
+is this non-overlapping behavior consistent with other directives, but it's
+also necessary to handle sets of non-unique strings or patterns.  For example,
+the following directives look for unordered log entries for two tasks in a
+parallel program, such as the OpenMP runtime:
+
+.. code-block:: text
+
+    // CHECK-DAG: [[THREAD_ID:[0-9]+]]: task_begin
+    // CHECK-DAG: [[THREAD_ID]]: task_end
+    //
+    // CHECK-DAG: [[THREAD_ID:[0-9]+]]: task_begin
+    // CHECK-DAG: [[THREAD_ID]]: task_end
+
+The second pair of directives is guaranteed not to match the same log entries
+as the first pair even though the patterns are identical and even if the text
+of the log entries is identical because the thread ID manages to be reused.
+
 The "CHECK-LABEL:" directive
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~