standards: add .editorconfig and per-area .clang-format configs

Editor defaults at the repo root; kernel/ uses Linux kernel style (tabs,
width 8, ~80 cols) and userspace//tools/ use LLVM base with 4-space indent
and ~100 cols. Configs govern new code and edited hunks only: existing
files are not to be mass-reformatted (recorded in the file headers and
docs/07-developers/onboarding-and-standards.md 3.1/3.2).

1 files changed, 38 insertions, 0 deletions

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..fd0ee61
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,38 @@
+# Open-IOV editor defaults. Per-area .clang-format files govern C layout;
+# tools must not mass-reformat existing files (see
+# docs/07-developers/onboarding-and-standards.md section 3).
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+[*.md]
+trim_trailing_whitespace = false
+
+[Makefile]
+indent_style = tab
+indent_size = 8
+
+# Host kernel module: Linux kernel C style (tabs, tab width 8, ~80 columns).
+[kernel/**.{c,h}]
+indent_style = tab
+indent_size = 8
+tab_width = 8
+
+# Userspace library: LLVM base, 4 spaces, ~100 columns.
+[userspace/**.{c,h}]
+indent_style = space
+indent_size = 4
+tab_width = 4
+
+# Tools: LLVM base, 4 spaces, ~100 columns.
+[tools/**.{c,h}]
+indent_style = space
+indent_size = 4
+tab_width = 4