Start linting against global variables

6 files changed, 71 insertions, 8 deletions

diff --git a/.editorconfig b/.editorconfig
index 0baab4f..4bf1ae1 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -33,7 +33,7 @@ _mode = 9p
 [{lib9p/tests/test_server/static.h.gen,build-aux/embed-sources.h.gen,build-aux/lint-{generic,unknown},build-aux/get-dscname}]
 _mode = sh
 
-[{build-aux/lint-h,build-aux/linux-errno.txt.gen,libusb/include/libusb/tusb_helpers.h.gen,lib9p/tests/runtest}]
+[{build-aux/lint-h,build-aux/lint-bin,build-aux/linux-errno.txt.gen,libusb/include/libusb/tusb_helpers.h.gen,lib9p/tests/runtest}]
 _mode = bash
 
 [{lib9p/idl.gen,lib9p/include/lib9p/linux-errno.h.gen,build-aux/stack.c.gen}]
diff --git a/build-aux/lint-bin b/build-aux/lint-bin
new file mode 100755
index 0000000..2fe8e4b
--- /dev/null
+++ b/build-aux/lint-bin
@@ -0,0 +1,63 @@
+#!/usr/bin/env bash
+# build-aux/lint-bin - Lint final binary images
+#
+# Copyright (C) 2025  Luke T. Shumaker <lukeshu@lukeshu.com>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+set -euE -o pipefail
+
+# Output is a series of lines in the format "symbol location size
+# source".  Whitespace may seem silly.
+objdump_globals() {
+	sed -E -n '/^ \.t?(data|bss)\./{ / 0x/{ p; D; }; N; s/\n/ /; p; }' <"$1"
+}
+
+lint_globals() {
+	local in_mapfile
+	in_mapfile=$1
+
+	local rel_base
+	rel_base=${in_mapfile#build/*/}
+	rel_base=${rel_base%/*}
+
+	local topdir
+	topdir=$PWD
+
+	{
+		echo 'Source Symbol Size'
+		objdump_globals "$in_mapfile" |
+			{
+				cd "$rel_base"
+				total=0
+				while read -r symbol addr size source; do
+					: "$addr"
+					case "$source" in
+						/*)
+							# libg.a(whatever.o) -> libg.a
+							source="${source%(*)}"
+							# resolve `..` components
+							source="$(realpath --canonicalize-missing --no-symlinks -- "$source")"
+							;;
+						CMakeFiles/*.dir/*.obj)
+							# CMakeFiles/sbc_harnes_objs.dir/...
+							source="${source#CMakeFiles/*.dir/}"
+							source="${source%.obj}"
+							source="${source//__/..}"
+							source="$(realpath --canonicalize-missing --no-symlinks --relative-to="$topdir" -- "$source")"
+							;;
+					esac
+					printf '%s %s 0x%04x\n' "$source" "$symbol" "$size"
+					total=$((total + size))
+				done
+				printf '~ Total 0x%04x\n' "$total"
+			} |
+			LC_COLLATE=C sort
+	} | column -t
+}
+
+main() {
+	echo 'Global variables:'
+	lint_globals 'build/rp2040-Release/cmd/sbc_harness/sbc_harness.elf.map' | sed 's/^/  /'
+}
+
+main "$@"
diff --git a/cmd/sbc_harness/main.c b/cmd/sbc_harness/main.c
index ce80711..157f51e 100644
--- a/cmd/sbc_harness/main.c
+++ b/cmd/sbc_harness/main.c
@@ -67,7 +67,7 @@ static COROUTINE read9p_cr(void *) {
 	cr_end();
 }
 
-const char *hexdig = "0123456789ABCDEF";
+const char *const hexdig = "0123456789ABCDEF";
 static_assert(CONFIG_9P_SRV_MAX_REQS*_CONFIG_9P_NUM_SOCKS <= 16);
 
 COROUTINE init_cr(void *) {
diff --git a/lib9p/9p.generated.c b/lib9p/9p.generated.c
index eca0666..fe042e6 100644
--- a/lib9p/9p.generated.c
+++ b/lib9p/9p.generated.c
@@ -48,7 +48,7 @@
 
 /* strings ********************************************************************/
 
-const char *_lib9p_table_ver_name[LIB9P_VER_NUM] = {
+const char *const _lib9p_table_ver_name[LIB9P_VER_NUM] = {
 	[LIB9P_VER_unknown] = "unknown",
 #if CONFIG_9P_ENABLE_9P2000
 	[LIB9P_VER_9P2000] = "9P2000",
@@ -68,7 +68,7 @@ const char *_lib9p_table_ver_name[LIB9P_VER_NUM] = {
 };
 
 #define _MSG_NAME(typ) [LIB9P_TYP_##typ] = #typ
-const char * _lib9p_table_msg_name[LIB9P_VER_NUM][0x100] = {
+const char *const _lib9p_table_msg_name[LIB9P_VER_NUM][0x100] = {
 	[LIB9P_VER_unknown] = {
 		_MSG_NAME(Tversion),
 		_MSG_NAME(Rversion),
diff --git a/lib9p/idl.gen b/lib9p/idl.gen
index f2b4f13..db5f37d 100755
--- a/lib9p/idl.gen
+++ b/lib9p/idl.gen
@@ -693,7 +693,7 @@ def gen_c(versions: set[str], typs: list[idl.Type]) -> str:
     ret += f"""
 /* strings ********************************************************************/
 
-const char *_{idprefix}table_ver_name[{c_ver_enum('NUM')}] = {{
+const char *const _{idprefix}table_ver_name[{c_ver_enum('NUM')}] = {{
 """
     for ver in ["unknown", *sorted(versions)]:
         if ver in versions:
@@ -704,7 +704,7 @@ const char *_{idprefix}table_ver_name[{c_ver_enum('NUM')}] = {{
 
     ret += "\n"
     ret += f"#define _MSG_NAME(typ) [{idprefix.upper()}TYP_##typ] = #typ\n"
-    ret += msg_table("msg", "name", "char *", (0, 0x100, 1))
+    ret += msg_table("msg", "name", "char *const", (0, 0x100, 1))
 
     # bitmasks #################################################################
     ret += f"""
diff --git a/lib9p/internal.h b/lib9p/internal.h
index d27348e..1f4975f 100644
--- a/lib9p/internal.h
+++ b/lib9p/internal.h
@@ -88,8 +88,8 @@ struct _lib9p_send_tentry {
 	_marshal_fn_t           marshal;
 };
 
-extern const char * _lib9p_table_ver_name[LIB9P_VER_NUM];
-extern const char * _lib9p_table_msg_name[LIB9P_VER_NUM][0x100];
+extern const char *const _lib9p_table_ver_name[LIB9P_VER_NUM];
+extern const char *const _lib9p_table_msg_name[LIB9P_VER_NUM][0x100];
 extern const uint32_t _lib9p_table_msg_min_size[LIB9P_VER_NUM];
 extern const struct _lib9p_recv_tentry _lib9p_table_Tmsg_recv[LIB9P_VER_NUM][0x80];
 extern const struct _lib9p_recv_tentry _lib9p_table_Rmsg_recv[LIB9P_VER_NUM][0x80];