Reapply "[llvm-cov] Add an -output-dir option for the show sub-command""

Passing -output-dir path/to/dir to llvm-cov show creates path/to/dir if
it doesn't already exist, and prints reports into that directory.

In function view mode, all views are written into
path/to/dir/functions.$EXTENSION. In file view mode, all views are
written into path/to/dir/coverage/$PATH.$EXTENSION.

Changes since the initial commit:

- Avoid accidentally closing stdout twice.

llvm-svn: 273985

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/docs/CommandGuide/llvm-cov.rst b/llvm/docs/CommandGuide/llvm-cov.rst
index 8e2806b0c61..35a7a036456 100644
--- a/llvm/docs/CommandGuide/llvm-cov.rst
+++ b/llvm/docs/CommandGuide/llvm-cov.rst
@@ -240,6 +240,14 @@ OPTIONS
 
  Use the specified output format. The supported formats are: "text".
 
+.. option:: -output-dir=PATH
+
+ Specify a directory to write coverage reports into. If the directory does not
+ exist, it is created. When used in function view mode (i.e when -name or
+ -name-regex are used to select specific functions), the report is written to
+ PATH/functions.EXTENSION. When used in file view mode, a report for each file
+ is written to PATH/REL_PATH_TO_FILE.EXTENSION.
+
 .. option:: -line-coverage-gt=<N>
 
  Show code coverage only for functions with line coverage greater than the