[clang-format] change to v9.0.0 (#37)

CONTRIBUTING.md

@@ -109,7 +109,7 @@ This will open up a text editor where you can specify which commits to squash.
 
 #### Coding Conventions and Style
 
-OpenThread RTOS uses and enforces the [OpenThread Coding Conventions and Style](STYLE_GUIDE.md) on all code, except for code located in [third_party](third_party). Use `script/make-pretty` and `script/make-pretty check` to automatically reformat code and check for code-style compliance, respectively. OpenThread RTOS currently requires [clang-format v10.0.0](http://releases.llvm.org/download.html#10.0.0) for C/C++ and [yapf](https://github.com/google/yapf) for Python.
+OpenThread RTOS uses and enforces the [OpenThread Coding Conventions and Style](STYLE_GUIDE.md) on all code, except for code located in [third_party](third_party). Use `script/make-pretty` and `script/make-pretty check` to automatically reformat code and check for code-style compliance, respectively. OpenThread RTOS currently requires [clang-format v9.0.0](http://releases.llvm.org/download.html#9.0.0) for C/C++ and [yapf](https://github.com/google/yapf) for Python.
 
 As part of the cleanup process, you should also run `script/make-pretty check` to ensure that your code passes the baseline code style checks.
 

STYLE_GUIDE.md

@@ -116,7 +116,7 @@
 
 - OpenThread uses `script/make-pretty` to reformat code and enforce code format and style. `script/make-pretty check` is included in OpenThread's continuous integration and must pass before a pull request is merged.
 
-- `script/make-pretty` requires [clang-format v10.0.0](http://releases.llvm.org/download.html#10.0.0) for C/C++ and [yapf](https://github.com/google/yapf) for Python.
+- `script/make-pretty` requires [clang-format v9.0.0](http://releases.llvm.org/download.html#9.0.0) for C/C++ and [yapf](https://github.com/google/yapf) for Python.
 
 ### File Names
 

script/clang-format

@@ -27,7 +27,7 @@
 #  POSSIBILITY OF SUCH DAMAGE.
 #
 
-CLANG_FORMAT_VERSION="clang-format version 10.0"
+CLANG_FORMAT_VERSION="clang-format version 9.0"
 
 die()
 {
@@ -39,18 +39,18 @@ die()
 # expand_aliases shell option is set using shopt.
 shopt -s expand_aliases
 
-if command -v clang-format-10 >/dev/null; then
-    alias clang-format=clang-format-10
+if command -v clang-format-9 >/dev/null; then
+    alias clang-format=clang-format-9
 elif command -v clang-format >/dev/null; then
     case "$(clang-format --version)" in
         "$CLANG_FORMAT_VERSION"*) ;;
 
         *)
-            die "$(clang-format --version); clang-format 10.0 required"
+            die "$(clang-format --version); clang-format 9.0 required"
             ;;
     esac
 else
-    die "clang-format 10.0 required"
+    die "clang-format 9.0 required"
 fi
 
 clang-format "$@" || die

script/clang-format-check

@@ -35,7 +35,8 @@
 
 set -euo pipefail
 
-die() {
+die()
+{
     echo " *** ERROR:  $*"
     exit 1
 }