From bf7500ad7b3426f6aae7306044c213b41f21e14f Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Thu, 3 Jun 2021 18:14:15 +0200
Subject: [PATCH] dde_linux/create_dummies: out-of-tree build dir

This patch enables the tool/dde_linux/create_dummies tool to operate on
a out-of-tree build directory. The Linux source tree is determined by
examining the build directory's Makefile.

Issue #4188
---
 tool/dde_linux/create_dummies | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/tool/dde_linux/create_dummies b/tool/dde_linux/create_dummies
index 98e69780f0..e265f763d6 100755
--- a/tool/dde_linux/create_dummies
+++ b/tool/dde_linux/create_dummies
@@ -117,25 +117,34 @@ endif # COMMAND=generate
 
 ifneq ($(realpath $(LINUX_KERNEL_DIR)),)
 
-CROSS_DEV_PREFIX ?= /usr/local/genode/tool/current/bin/genode-$(TOOL_ARCH)-
-NM                = $(CROSS_DEV_PREFIX)nm --print-file-name --defined-only
-C_FILE_DEF       := $(shell $(NM) `find $(LINUX_KERNEL_DIR) -name "*.o" | grep -v vmlinux.o` | grep -i " t " | sed 's/o:[0-f]* [tT] /c:/')
-symbol_to_c_file  = $(firstword $(subst :, ,$(filter %:$(1),$(C_FILE_DEF))))
+# determine kernel source dir if an out-of-tree build directory is specified
+LINUX_SRC_DIR := $(LINUX_KERNEL_DIR)
+ifneq ($(shell grep "Automatically generated by" $(LINUX_KERNEL_DIR)/Makefile),)
+LINUX_SRC_DIR := $(shell sed -n "/^include/s/.* \(.*\)\/Makefile/\\1/p" $(LINUX_KERNEL_DIR)/Makefile)
+endif
 
+CROSS_DEV_PREFIX ?= /usr/local/genode/tool/current/bin/genode-$(TOOL_ARCH)-
+
+# gather list of <path.c>:<symbol> pairs, strip first path element (build dir)
+NM          = $(CROSS_DEV_PREFIX)nm --print-file-name --defined-only
+C_FILE_DEF := $(shell cd $(LINUX_KERNEL_DIR); $(NM) `find -name "*.o" -printf "%P\n" | grep -v vmlinux.o` | grep -i " t " | sed -e 's/o:[0-f]* [tT] /c:/')
+
+# query C_FILE_DEF database for a given symbol
+symbol_to_c_file  = $(addprefix $(LINUX_SRC_DIR)/, $(firstword $(subst :, ,$(filter %:$(1),$(C_FILE_DEF)))))
 
 #
 # Ctags database
 #
 
-HEADER_DECL      := $(shell cd $(LINUX_KERNEL_DIR)/include; ctags -R -x --kinds-c=p --_xformat="%N:%F" .)
-GLOBAL_VAR       := $(shell cd $(LINUX_KERNEL_DIR)/include; ctags -R -x --kinds-c=x --_xformat="%N:%F" .)
+HEADER_DECL      := $(shell cd $(LINUX_SRC_DIR)/include; ctags -R -x --kinds-c=p --_xformat="%N:%F" .)
+GLOBAL_VAR       := $(shell cd $(LINUX_SRC_DIR)/include; ctags -R -x --kinds-c=x --_xformat="%N:%F" .)
 func_to_h_file    = $(lastword $(subst :, ,$(filter $(1):%,$(HEADER_DECL))))
 do_func_to_def    = $(subst :, ,$(subst typename:,,$(subst $(1): ,,$(shell ctags -x --kinds-c=f --_xformat="%N: %t %N%S" $(2) | grep "^\<$(1)\>:"))))
 check_func_to_def = $(if $(2),$(call do_func_to_def,$(1),$(2)),)
 func_to_def       = $(call check_func_to_def,$(1),$(call symbol_to_c_file,$(1)))
 
 var_to_h_file     = $(lastword $(subst :, ,$(filter $(1):%,$(GLOBAL_VAR))))
-do_var_to_def     = $(subst ];,] = {};,$(subst \/,/,$(subst extern ,,$(subst $$/,,$(subst $(1): /^,,$(shell ctags -x --kinds-c=x --_xformat="%N: %P" $(LINUX_KERNEL_DIR)/include/$(2) | grep "^\<$(1)\>:"))))))
+do_var_to_def     = $(subst ];,] = {};,$(subst \/,/,$(subst extern ,,$(subst $$/,,$(subst $(1): /^,,$(shell ctags -x --kinds-c=x --_xformat="%N: %P" $(LINUX_SRC_DIR)/include/$(2) | grep "^\<$(1)\>:"))))))
 check_var_to_def  = $(if $(2),$(call do_var_to_def,$(1),$(2)),)
 var_to_def        = $(call check_var_to_def,$(1),$(call var_to_h_file,$(1)))
 
@@ -202,7 +211,7 @@ check_func = $(if $(2),$(call check_fdef,$(1),$(2),$(call func_to_def,$(1))),$(c
 ifeq ($(realpath $(LINUX_KERNEL_DIR)),)
 show_symbol = "$1"
 else
-show_symbol = "$1 $(foreach F,$(call symbol_to_c_file,$1),(found at $(F:.c=.o)))"
+show_symbol = "$1 $(foreach F,$(call symbol_to_c_file,$1),(found at $(subst $(LINUX_SRC_DIR)/,,$(F:.c=.o))))"
 endif
 
 show: