From 6c8489f4c539042b4b59b04c612ed940526f21e5 Mon Sep 17 00:00:00 2001
From: matthewcroughan <matt@croughan.sh>
Date: Tue, 17 Dec 2024 17:48:13 +0000
Subject: [PATCH] plugins/Makefile: use files to avoid hitting ARG_MAX during
 build

When adding more modules to the build, ar will be passed far more .o files as
arguments on the command line than the limits specified by most host kernels by
default, which will cause the build to fail with "/bin/bash: Argument list too long"

Using xargs can show you what these limits are on POSIX
systems, e.g:

$ xargs --show-limits
Your environment variables take up 6774 bytes
POSIX upper limit on argument length (this system): 2088330
POSIX smallest allowable upper limit on argument length (all systems): 4096
Maximum length of command we could actually use: 2081556
Size of command buffer we are actually using: 131072
Maximum parallelism (--max-procs must be no greater): 2147483647
---
 plugins/Makefile | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/plugins/Makefile b/plugins/Makefile
index 58bd3006..d92784d2 100644
--- a/plugins/Makefile
+++ b/plugins/Makefile
@@ -1438,6 +1438,7 @@ endif
 
 clean:
 	rm -f *.a
+	rm -f plugin_objs_list.txt mini_plugin_objs_list.txt
 	rm -rf $(BUILD_DIR)
 	rm -rf surgext/build
 
@@ -2060,12 +2061,18 @@ custom_per_file_names = -D${1}=${2}_${1}
 plugins$(TARGET_SUFFIX).a: $(PLUGIN_OBJS)
 	@echo "Creating $@"
 	$(SILENT)rm -f $@
-	$(SILENT)$(AR) crs $@ $^
+	# Write object file list to a response file and use it in the `ar` command
+	# to avoid hitting stack limits when using large number of modules
+	$(SILENT)$(file > plugin_objs_list.txt,$(PLUGIN_OBJS))
+	$(SILENT)$(AR) crs $@ @plugin_objs_list.txt
+	$(SILENT)rm -f plugin_objs_list.txt
 
 plugins-mini$(TARGET_SUFFIX).a: $(MINIPLUGIN_OBJS)
 	@echo "Creating $@"
 	$(SILENT)rm -f $@
-	$(SILENT)$(AR) crs $@ $^
+	$(SILENT)$(file > mini_plugin_objs_list.txt,$(MINIPLUGIN_OBJS))
+	$(SILENT)$(AR) crs $@ @mini_plugin_objs_list.txt
+	$(SILENT)rm -f mini_plugin_objs_list.txt
 
 $(BUILD_DIR)/%.bin.c: % ../deps/res2c.py
 	-@mkdir -p "$(shell dirname $(BUILD_DIR)/$<)"