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Variable context
From: |
Marco Gerards |
Subject: |
Variable context |
Date: |
Sat, 29 Apr 2006 22:05:14 +0200 |
User-agent: |
Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) |
Hi,
Here is a patch for making variables dependant on the context. Now
when the user uses configfile, another context is created. Like in
bash you can make variables global by using `export'.
--
Marco
2006-04-29 Marco Gerards <address@hidden>
* commands/configfile.c (grub_cmd_configfile): Execute the
configfile within its own context.
* include/grub/env.h (grub_env_context_open): New prototype.
(grub_env_context_close): Likewise.
(grub_env_init): Likewise.
* kern/env.c (grub_env): Removed.
(grub_env_sorted): Likewise.
(grub_env_context): New variable.
(grub_env_var_context): Likewise.
(grub_env_find): Search both the active context and the global
context.
(grub_env_context_open): New function.
(grub_env_context_close): Likewise.
(grub_env_init): Likewise.
(grub_env_insert): Likewise.
(grub_env_remove): Likewise.
(grub_env_export): Likewise.
(grub_env_set): Changed to use helper functions to avoid code
duplication.
(grub_env_iterate): Rewritten so both the current context and the
global context are being used.
* kern/i386/pc/init.c (grub_machine_init): Call `grub_env_init'.
* kern/powerpc/ieee1275/init.c (grub_machine_init): Likewise.
* kern/sparc64/ieee1275/init.c (grub_machine_init): Likewise.
* util/grub-emu.c (grub_machine_init): Likewise.
* kern/efi/init.c (grub_efi_init): Likewise.
* normal/command.c (export_command): New function.
(grub_command_init): Register the `export' function.
Index: commands/configfile.c
===================================================================
RCS file: /sources/grub/grub2/commands/configfile.c,v
retrieving revision 1.3
diff -u -p -u -p -r1.3 configfile.c
--- commands/configfile.c 13 Nov 2005 15:47:08 -0000 1.3
+++ commands/configfile.c 29 Apr 2006 20:02:17 -0000
@@ -1,7 +1,7 @@
/* configfile.c - command to manually load config file */
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2005 Free Software Foundation, Inc.
+ * Copyright (C) 2005,2006 Free Software Foundation, Inc.
*
* GRUB is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -33,7 +33,9 @@ grub_cmd_configfile (struct grub_arg_lis
return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name required");
grub_cls ();
+ grub_env_context_open ();
grub_normal_execute (args[0], 1);
+ grub_env_context_close ();
return 0;
}
Index: include/grub/env.h
===================================================================
RCS file: /sources/grub/grub2/include/grub/env.h,v
retrieving revision 1.3
diff -u -p -u -p -r1.3 env.h
--- include/grub/env.h 20 Jul 2005 20:30:45 -0000 1.3
+++ include/grub/env.h 29 Apr 2006 20:02:17 -0000
@@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2003,2005 Free Software Foundation, Inc.
+ * Copyright (C) 2003,2005,2006 Free Software Foundation, Inc.
*
* GRUB is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -50,5 +50,8 @@ void EXPORT_FUNC(grub_env_iterate) (int
grub_err_t EXPORT_FUNC(grub_register_variable_hook) (const char *var,
grub_env_read_hook_t
read_hook,
grub_env_write_hook_t
write_hook);
+grub_err_t EXPORT_FUNC(grub_env_context_open) (void);
+grub_err_t EXPORT_FUNC(grub_env_context_close) (void);
+grub_err_t EXPORT_FUNC(grub_env_init) (void);
#endif /* ! GRUB_ENV_HEADER */
Index: kern/env.c
===================================================================
RCS file: /sources/grub/grub2/kern/env.c,v
retrieving revision 1.5
diff -u -p -u -p -r1.5 env.c
--- kern/env.c 25 Dec 2005 17:21:52 -0000 1.5
+++ kern/env.c 29 Apr 2006 20:02:17 -0000
@@ -1,7 +1,7 @@
/* env.c - Environment variables */
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2003,2005 Free Software Foundation, Inc.
+ * Copyright (C) 2003,2005,2006 Free Software Foundation, Inc.
*
* GRUB is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -26,10 +26,21 @@
#define HASHSZ 13
/* A hashtable for quick lookup of variables. */
-static struct grub_env_var *grub_env[HASHSZ];
+struct grub_env_context
+{
+ struct grub_env_var *vars[HASHSZ];
+
+ struct grub_env_var *sorted;
+
+ /* One level deeper on the stack. */
+ struct grub_env_context *next;
+};
+
+/* The global context for environment variables. */
+static struct grub_env_context *grub_env_context;
-/* The variables in a sorted list. */
-static struct grub_env_var *grub_env_sorted;
+/* The nested contexts for regular variables. */
+static struct grub_env_context *grub_env_var_context;
/* Return the hash representation of the string S. */
static unsigned int grub_env_hashval (const char *s)
@@ -49,20 +60,155 @@ grub_env_find (const char *name)
struct grub_env_var *var;
int idx = grub_env_hashval (name);
- for (var = grub_env[idx]; var; var = var->next)
+ /* Look for the variable in the current context. */
+ for (var = grub_env_var_context->vars[idx]; var; var = var->next)
if (! grub_strcmp (var->name, name))
return var;
+
+ /* Look for the variable in the environment context. */
+ for (var = grub_env_context->vars[idx]; var; var = var->next)
+ if (! grub_strcmp (var->name, name))
+ return var;
+
return 0;
}
grub_err_t
-grub_env_set (const char *var, const char *val)
+grub_env_context_open (void)
{
- int idx = grub_env_hashval (var);
+ struct grub_env_context *context;
+ int i;
+
+ context = grub_malloc (sizeof (*context));
+ if (! context)
+ return grub_errno;
+
+ for (i = 0; i < HASHSZ; i++)
+ context->vars[i] = 0;
+ context->next = grub_env_var_context;
+ context->sorted = 0;
+
+ grub_env_var_context = context;
+
+ return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_context_close (void)
+{
+ struct grub_env_context *context;
struct grub_env_var *env;
+ struct grub_env_var *prev = 0;
+
+ context = grub_env_var_context->next;
+
+ /* Free the variables associated with this context. */
+ for (env = grub_env_var_context->sorted; env; env = env->sort_next)
+ {
+ /* XXX: What if a hook is associated with this variable? */
+ grub_free (prev);
+ prev = env;
+ }
+ grub_free (prev);
+
+ /* Restore the previous context. */
+ grub_free (grub_env_var_context);
+ grub_env_var_context = context;
+
+ return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_init (void)
+{
+ grub_err_t err;
+
+ /* Create the hashtable for the environment variables. */
+ err = grub_env_context_open ();
+ if (err)
+ return err;
+
+ /* Use this one for environment variables only. */
+ grub_env_context = grub_env_var_context;
+
+ return GRUB_ERR_NONE;
+}
+
+static void
+grub_env_insert (struct grub_env_context *context,
+ struct grub_env_var *env)
+{
+ struct grub_env_var **grub_env = context->vars;
struct grub_env_var *sort;
struct grub_env_var **sortp;
-
+ int idx = grub_env_hashval (env->name);
+
+ /* Insert it in the hashtable. */
+ env->prevp = &grub_env[idx];
+ env->next = grub_env[idx];
+ if (grub_env[idx])
+ grub_env[idx]->prevp = &env->next;
+ grub_env[idx] = env;
+
+ /* Insert it in the sorted list. */
+ sortp = &context->sorted;
+ sort = context->sorted;
+ while (sort)
+ {
+ if (grub_strcmp (sort->name, env->name) > 0)
+ break;
+
+ sortp = &sort->sort_next;
+ sort = sort->sort_next;
+ }
+ env->sort_prevp = sortp;
+ env->sort_next = sort;
+ if (sort)
+ sort->sort_prevp = &env->sort_next;
+ *sortp = env;
+}
+
+
+static void
+grub_env_remove (struct grub_env_var *env)
+{
+ /* Remove the entry from the variable table. */
+ *env->prevp = env->next;
+ if (env->next)
+ env->next->prevp = env->prevp;
+
+ /* And from the sorted list. */
+ *env->sort_prevp = env->sort_next;
+ if (env->sort_next)
+ env->sort_next->sort_prevp = env->sort_prevp;
+}
+
+grub_err_t
+grub_env_export (const char *var)
+{
+ struct grub_env_var *env;
+ int idx = grub_env_hashval (var);
+
+ /* Look for the variable in the current context only. */
+ for (env = grub_env_var_context->vars[idx]; env; env = env->next)
+ if (! grub_strcmp (env->name, var))
+ {
+ /* Remove the variable from the old context and reinsert it
+ into the environment. */
+ grub_env_remove (env);
+ grub_env_insert (grub_env_context, env);
+
+ return GRUB_ERR_NONE;
+ }
+
+ return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_set (const char *var, const char *val)
+{
+ struct grub_env_var *env;
+
/* If the variable does already exist, just update the variable. */
env = grub_env_find (var);
if (env)
@@ -98,30 +244,8 @@ grub_env_set (const char *var, const cha
env->value = grub_strdup (val);
if (! env->value)
goto fail;
-
- /* Insert it in the hashtable. */
- env->prevp = &grub_env[idx];
- env->next = grub_env[idx];
- if (grub_env[idx])
- grub_env[idx]->prevp = &env->next;
- grub_env[idx] = env;
-
- /* Insert it in the sorted list. */
- sortp = &grub_env_sorted;
- sort = grub_env_sorted;
- while (sort)
- {
- if (grub_strcmp (sort->name, var) > 0)
- break;
-
- sortp = &sort->sort_next;
- sort = sort->sort_next;
- }
- env->sort_prevp = sortp;
- env->sort_next = sort;
- if (sort)
- sort->sort_prevp = &env->sort_next;
- *sortp = env;
+
+ grub_env_insert (grub_env_var_context, env);
return 0;
@@ -160,13 +284,7 @@ grub_env_unset (const char *name)
if (env->read_hook || env->write_hook)
return;
- *env->prevp = env->next;
- if (env->next)
- env->next->prevp = env->prevp;
-
- *env->sort_prevp = env->sort_next;
- if (env->sort_next)
- env->sort_next->sort_prevp = env->sort_prevp;
+ grub_env_remove (env);
grub_free (env->name);
grub_free (env->value);
@@ -177,11 +295,32 @@ grub_env_unset (const char *name)
void
grub_env_iterate (int (* func) (struct grub_env_var *var))
{
- struct grub_env_var *env;
+ struct grub_env_var *env = grub_env_context->sorted;
+ struct grub_env_var *var = grub_env_var_context->sorted;
+
+ /* Initially these are the same. */
+ if (env == var)
+ var = 0;
- for (env = grub_env_sorted; env; env = env->sort_next)
- if (func (env))
- return;
+ while (env || var)
+ {
+ struct grub_env_var **cur;
+
+ /* Select the first name to be printed from the head of two
+ sorted lists. */
+ if (! env)
+ cur = &var;
+ else if (! var)
+ cur = &env;
+ else if (grub_strcmp (env->name, var->name) > 0)
+ cur = &var;
+ else
+ cur = &env;
+
+ if (func (*cur))
+ return;
+ *cur = (*cur)->sort_next;
+ }
}
grub_err_t
Index: kern/efi/init.c
===================================================================
RCS file: /sources/grub/grub2/kern/efi/init.c,v
retrieving revision 1.3
diff -u -p -u -p -r1.3 init.c
--- kern/efi/init.c 25 Apr 2006 20:08:31 -0000 1.3
+++ kern/efi/init.c 29 Apr 2006 20:02:17 -0000
@@ -38,6 +38,8 @@ grub_efi_init (void)
/* Initialize the memory management system. */
grub_efi_mm_init ();
+ grub_env_init ();
+
grub_efidisk_init ();
}
Index: kern/i386/pc/init.c
===================================================================
RCS file: /sources/grub/grub2/kern/i386/pc/init.c,v
retrieving revision 1.12
diff -u -p -u -p -r1.12 init.c
--- kern/i386/pc/init.c 25 Apr 2006 20:08:31 -0000 1.12
+++ kern/i386/pc/init.c 29 Apr 2006 20:02:17 -0000
@@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ * Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -226,6 +226,8 @@ grub_machine_init (void)
/* The memory system was initialized, thus register built-in devices. */
grub_biosdisk_init ();
+
+ grub_env_init ();
}
void
Index: kern/powerpc/ieee1275/init.c
===================================================================
RCS file: /sources/grub/grub2/kern/powerpc/ieee1275/init.c,v
retrieving revision 1.25
diff -u -p -u -p -r1.25 init.c
--- kern/powerpc/ieee1275/init.c 26 Apr 2006 02:20:12 -0000 1.25
+++ kern/powerpc/ieee1275/init.c 29 Apr 2006 20:02:17 -0000
@@ -1,7 +1,7 @@
/* init.c -- Initialize GRUB on the newworld mac (PPC). */
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ * Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -134,6 +134,8 @@ grub_machine_init (void)
}
grub_mm_init_region ((void *) grub_heap_start, grub_heap_len);
+ grub_env_init ();
+
grub_ofdisk_init ();
/* Process commandline. */
Index: kern/sparc64/ieee1275/init.c
===================================================================
RCS file: /sources/grub/grub2/kern/sparc64/ieee1275/init.c,v
retrieving revision 1.2
diff -u -p -u -p -r1.2 init.c
--- kern/sparc64/ieee1275/init.c 25 Apr 2006 20:08:31 -0000 1.2
+++ kern/sparc64/ieee1275/init.c 29 Apr 2006 20:02:17 -0000
@@ -1,7 +1,7 @@
/* init.c -- Initialize GRUB on the Ultra Sprac (sparc64). */
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ * Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -156,6 +156,8 @@ grub_machine_init (void)
grub_heap_len);
grub_mm_init_region ((void *) grub_heap_start, grub_heap_len);
+ grub_env_init ();
+
grub_ofdisk_init ();
/* Process commandline. */
Index: normal/command.c
===================================================================
RCS file: /sources/grub/grub2/normal/command.c,v
retrieving revision 1.16
diff -u -p -u -p -r1.16 command.c
--- normal/command.c 16 Apr 2006 18:02:42 -0000 1.16
+++ normal/command.c 29 Apr 2006 20:02:17 -0000
@@ -1,6 +1,6 @@
/*
* GRUB -- GRand Unified Bootloader
- * Copyright (C) 2003,2005 Free Software Foundation, Inc.
+ * Copyright (C) 2003,2005,2006 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -284,6 +284,18 @@ unset_command (struct grub_arg_list *sta
}
static grub_err_t
+export_command (struct grub_arg_list *state __attribute__ ((unused)),
+ int argc, char **args)
+{
+ if (argc < 1)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT,
+ "no environment variable specified");
+
+ grub_env_export (args[0]);
+ return 0;
+}
+
+static grub_err_t
insmod_command (struct grub_arg_list *state __attribute__ ((unused)),
int argc, char **args)
{
@@ -367,6 +379,9 @@ grub_command_init (void)
grub_register_command ("unset", unset_command, GRUB_COMMAND_FLAG_BOTH,
"unset ENVVAR", "Remove an environment variable.", 0);
+ grub_register_command ("export", export_command, GRUB_COMMAND_FLAG_BOTH,
+ "export ENVVAR", "Export a variable.", 0);
+
grub_register_command ("insmod", insmod_command, GRUB_COMMAND_FLAG_BOTH,
"insmod MODULE",
"Insert a module. The argument can be a file or a
module name.",
Index: util/grub-emu.c
===================================================================
RCS file: /sources/grub/grub2/util/grub-emu.c,v
retrieving revision 1.29
diff -u -p -u -p -r1.29 grub-emu.c
--- util/grub-emu.c 26 Apr 2006 21:58:36 -0000 1.29
+++ util/grub-emu.c 29 Apr 2006 20:02:17 -0000
@@ -83,6 +83,7 @@ void
grub_machine_init (void)
{
signal (SIGINT, SIG_IGN);
+ grub_env_init ();
grub_console_init ();
}
- Variable context,
Marco Gerards <=