我正在尝试在我的 Linux 内核开发项目中使用 Emacs 作为 IDE。所以我毫无问题地安装了 CEDET 和 GNU Global (gtags)。
当我打开属于我的 Linux 内核源文件夹的 C 源代码时，会自动检测到 linux 项目。正确突出显示函数、变量、标题和其他关键字。
通过 ~/.emacs 文件，我配置了语义的代码完成和智能感知。因此，当我按 C- 时，代码完成菜单出现，我可以选择需要的内容。
问题是当我使用预处理器定义时，智能感知系统在当前位置显示菜单，但在调用时未检测到正确的内容 (C-)。即使我关闭并重新启动 emacs，也会重现相同的行为。
测试代码为：
//------------------------------------------------ --------------------------------------
typedef struct
{
int p1;
#ifdef __KERNEL__
int p2;
#endif
#ifdef USE1
char p3;
#endif
#ifdef __LINUX_ARM_ARCH__
int p4;
#endif
}OBJ;
OBJ g_obj;
//------------------------------------------------ --------------------------------------
KERNEL、 USE1 和LINUX_ARM_ARCH已经定义如下：
__KERNEL__ : (add-to-list 'semantic-lex-c-preprocessor-symbol-map '("__KERNEL__" . "")) in .emacs
USE1 : defined in a header file included by the current C source file.
__LINUX_ARM_ARCH__ : (add-to-list 'semantic-lex-c-preprocessor-symbol-file "/home/abdellatif/kernel/include/generated/autoconf.h") in .emacs
在 .emacs 文件中，我还添加了 GCC 交叉编译器（GCC for ARM）构建内核项目所需的所有包含和定义。
我还尝试强制语义使用 GCC 交叉编译器命令行代替系统 GCC 来正确预处理，但还没有找到如何做到这一点。
“Mx semantic-c-describe-environment”命令显示正确的包含路径和定义（在 .emacs 中设置）。但也列出了 GCC 定义的系统。
.emacs 文件和软件版本如下所示。
欢迎任何帮助或指示:) 最好的问候
############# Software versions #############
- Emacs (23.2.1)
- Ubuntu machine (natty, 11.04)
- Cedet 1.0 (from http://cedet.sourceforge.net/)
############# .emacs #############
;load CEDET
(load-file "~/Documents/my_emacs/cedet-1.0/common/cedet.el")
(require 'ede)
(global-ede-mode t)
; turn on which-func support (plus all other code helpers)
(semantic-load-enable-gaudy-code-helpers)
(semantic-load-enable-excessive-code-helpers)
; turn on all "useful" features
(setq semantic-load-turn-useful-things-on t)
(setq-mode-local c-mode
semanticdb-find-default-throttle
'(project unloaded system recursive))
;init names completion, and displaying of information for tags & classes
(require 'semantic-ia)
;preprocessing of source code
(require 'semantic-c)
(semantic-reset-system-include 'c-mode)
(semantic-reset-system-include 'c++-mode)
(semantic-add-system-include "/home/abdellatif/toolchain/arm-eabi-4.4.3/lib/gcc/arm-eabi/4.4.3/include" 'c-mode)
(semantic-add-system-include "/home/abdellatif/kernel/arch/arm/include" 'c-mode)
(semantic-add-system-include "/home/abdellatif/kernel/include" 'c-mode)
(semantic-add-system-include "/home/abdellatif/kernel/arch/arm/mach-omap2/include" 'c-mode)
(semantic-add-system-include "/home/abdellatif/kernel/arch/arm/plat-omap/include" 'c-mode)
(add-to-list 'semantic-lex-c-preprocessor-symbol-file "/home/abdellatif/kernel/include/generated/autoconf.h")
(add-to-list 'semantic-lex-c-preprocessor-symbol-map '("__KERNEL__" . ""))
(add-to-list 'semantic-lex-c-preprocessor-symbol-map '("__LINUX_ARM_ARCH__" . "7"))
(add-to-list 'semantic-lex-c-preprocessor-symbol-map '("KBUILD_STR(s)" . "#s"))
(add-to-list 'semantic-lex-c-preprocessor-symbol-map '("KBUILD_BASENAME" . "KBUILD_STR(main)"))
(add-to-list 'semantic-lex-c-preprocessor-symbol-map '("KBUILD_MODNAME" . "KBUILD_STR(main)"))
;semantic integration with imenu (display of a menu with a list of functions, variables, and other tags)
(defun my-semantic-hook ()
(imenu-add-to-menubar "TAGS"))
(add-hook 'semantic-init-hooks 'my-semantic-hook)
;names completion (semantic commands)
(defun my-cedet-hook ()
(local-set-key [(control return)] 'semantic-ia-complete-symbol)
(local-set-key "\C-x " 'semantic-ia-complete-symbol-menu)
(local-set-key "\C-x\r" 'gtags-find-tag-from-here))
(add-hook 'c-mode-common-hook 'my-cedet-hook)
;navigating in source code
(semantic-mru-bookmark-mode 1)
;tell semantic to store its tags database between sessions here
(require 'semanticdb)
(setq-default semanticdb-default-save-directory "~/.semantic.cache")
(setq-default semanticdb-default-system-save-directory "~/.semantic.cache")
;allow Semanticdb use databases generated by global(gtags)
(require 'semanticdb-global)
(semanticdb-enable-gnu-global-databases 'c-mode)