[Qemu-devel] [PATCH 1/4] Add module infrastructure to QEMU

[Anthony Liguori <aliguori@us.ibm.com>]

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/Makefile b/Makefile
index 8649938..5c53801 100644
--- a/Makefile
+++ b/Makefile
@@ -63,7 +63,7 @@ recurse-all: $(SUBDIR_RULES)
 #######################################################################
 # BLOCK_OBJS is code used by both qemu system emulation and qemu-img
 
-BLOCK_OBJS=cutils.o cache-utils.o qemu-malloc.o
+BLOCK_OBJS=cutils.o cache-utils.o qemu-malloc.o module.o
 BLOCK_OBJS+=block-cow.o block-qcow.o aes.o block-vmdk.o block-cloop.o
 BLOCK_OBJS+=block-dmg.o block-bochs.o block-vpc.o block-vvfat.o
 BLOCK_OBJS+=block-qcow2.o block-parallels.o block-nbd.o
diff --git a/Makefile.target b/Makefile.target
index fe83837..c08c6fd 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -340,14 +340,13 @@ ifeq ($(TARGET_ARCH), m68k)
 OBJS+= m68k-sim.o m68k-semi.o
 endif
 
-OBJS+= libqemu.a
-
 # Note: this is a workaround. The real fix is to avoid compiling
 # cpu_signal_handler() in cpu-exec.c.
 signal.o: CFLAGS += $(HELPER_CFLAGS)
 
-$(QEMU_PROG): $(OBJS) ../libqemu_user.a
-	$(LINK)
+$(QEMU_PROG): ARLIBS=../libqemu_user.a libqemu.a
+$(QEMU_PROG): $(OBJS) ../libqemu_user.a libqemu.a
+	$(call LINK,$(OBJS))
 ifeq ($(ARCH),alpha)
 # Mark as 32 bit binary, i. e. it will be mapped into the low 31 bit of
 # the address space (31 bit so sign extending doesn't matter)
@@ -372,14 +371,13 @@ LIBS+=-lmx
 OBJS= main.o commpage.o machload.o mmap.o signal.o syscall.o thunk.o \
       gdbstub.o gdbstub-xml.o
 
-OBJS+= libqemu.a
-
 # Note: this is a workaround. The real fix is to avoid compiling
 # cpu_signal_handler() in cpu-exec.c.
 signal.o: CFLAGS += $(HELPER_CFLAGS)
 
-$(QEMU_PROG): $(OBJS)
-	$(LINK)
+$(QEMU_PROG): ARLIBS=libqemu.a
+$(QEMU_PROG): $(OBJS) libqemu.a
+	$(call LINK,$(OBJS))
 
 endif #CONFIG_DARWIN_USER
 
@@ -473,14 +471,13 @@ OBJS= main.o bsdload.o elfload.o mmap.o path.o signal.o strace.o syscall.o \
       gdbstub.o gdbstub-xml.o
 OBJS+= uaccess.o
 
-OBJS+= libqemu.a
-
 # Note: this is a workaround. The real fix is to avoid compiling
 # cpu_signal_handler() in cpu-exec.c.
 signal.o: CFLAGS += $(HELPER_CFLAGS)
 
-$(QEMU_PROG): $(OBJS) ../libqemu_user.a
-	$(LINK)
+$(QEMU_PROG): ARLIBS=libqemu.a ../libqemu_user.a
+$(QEMU_PROG): $(OBJS) libqemu.a ../libqemu_user.a
+	$(call LINK,$(OBJS))
 
 endif #CONFIG_BSD_USER
 
@@ -497,14 +494,6 @@ OBJS+=fw_cfg.o
 ifdef CONFIG_KVM
 OBJS+=kvm.o kvm-all.o
 endif
-ifdef CONFIG_WIN32
-OBJS+=block-raw-win32.o
-else
-ifdef CONFIG_AIO
-OBJS+=posix-aio-compat.o
-endif
-OBJS+=block-raw-posix.o
-endif
 
 LIBS+=-lz
 ifdef CONFIG_ALSA
@@ -724,9 +713,9 @@ endif
 vl.o: qemu-options.h
 
 $(QEMU_PROG): LIBS += $(SDL_LIBS) $(COCOA_LIBS) $(CURSES_LIBS) $(BRLAPI_LIBS) $(VDE_LIBS)
-
+$(QEMU_PROG): ARLIBS=../libqemu_common.a libqemu.a
 $(QEMU_PROG): $(OBJS) ../libqemu_common.a libqemu.a
-	$(LINK)
+	$(call LINK,$(OBJS))
 
 endif # !CONFIG_USER_ONLY
 
diff --git a/module.c b/module.c
new file mode 100644
index 0000000..2db2dad
--- /dev/null
+++ b/module.c
@@ -0,0 +1,137 @@
+/*
+ * QEMU Module Infrastructure
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "sys-queue.h"
+#include "module.h"
+
+typedef struct ModuleEntry
+{
+    int priority;
+    int is_init;
+    union {
+        int (*init)(void);
+        void (*exit)(void);
+    };
+    TAILQ_ENTRY(ModuleEntry) node;
+} ModuleEntry;
+
+typedef struct ModulePriorityList
+{
+    int priority;
+    TAILQ_HEAD(, ModuleEntry) entry_list;
+    TAILQ_ENTRY(ModulePriorityList) node;
+} ModulePriorityList;
+
+static TAILQ_HEAD(, ModulePriorityList) priority_list;
+
+static ModulePriorityList *find_priority_or_alloc(int priority, int alloc)
+{
+    ModulePriorityList *n;
+
+    TAILQ_FOREACH(n, &priority_list, node) {
+        if (priority >= n->priority)
+            break;
+    }
+
+    if (!n || n->priority != priority) {
+        ModulePriorityList *o;
+
+        if (!alloc)
+            return NULL;
+
+        o = qemu_mallocz(sizeof(*o));
+        o->priority = priority;
+        TAILQ_INIT(&o->entry_list);
+
+        if (n) {
+            TAILQ_INSERT_AFTER(&priority_list, n, o, node);
+        } else {
+            TAILQ_INSERT_HEAD(&priority_list, o, node);
+        }
+
+        n = o;
+    }
+
+    return n;
+}
+
+void register_module_init(int (*fn)(void), int priority)
+{
+    ModuleEntry *e;
+    ModulePriorityList *l;
+
+    e = qemu_mallocz(sizeof(*e));
+    e->is_init = 1;
+    e->init = fn;
+
+    l = find_priority_or_alloc(priority, 1);
+
+    TAILQ_INSERT_TAIL(&l->entry_list, e, node);
+}
+
+void register_module_exit(void (*fn)(void), int priority)
+{
+    ModuleEntry *e;
+    ModulePriorityList *l;
+
+    e = qemu_mallocz(sizeof(*e));
+    e->is_init = 0;
+    e->exit = fn;
+
+    l = find_priority_or_alloc(priority, 1);
+
+    TAILQ_INSERT_TAIL(&l->entry_list, e, node);
+}
+
+int module_call_init(int priority)
+{
+    ModulePriorityList *l;
+    ModuleEntry *e;
+
+    l = find_priority_or_alloc(priority, 0);
+    if (!l) {
+        return 0;
+    }
+
+    TAILQ_FOREACH(e, &l->entry_list, node) {
+        int ret;
+
+        if (!e->is_init) {
+            continue;
+        }
+
+        ret = e->init();
+        if (ret != 0)
+            return ret;
+    }
+
+    return 0;
+}
+
+void module_call_exit(int priority)
+{
+    ModulePriorityList *l;
+    ModuleEntry *e;
+
+    l = find_priority_or_alloc(priority, 0);
+    if (!l) {
+        return;
+    }
+
+    TAILQ_FOREACH(e, &l->entry_list, node) {
+        if (!e->is_init) {
+            e->exit();
+        }
+    }
+}
diff --git a/module.h b/module.h
new file mode 100644
index 0000000..5aa3eaa
--- /dev/null
+++ b/module.h
@@ -0,0 +1,41 @@
+/*
+ * QEMU Module Infrastructure
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_MODULE_H
+#define QEMU_MODULE_H
+
+#define module_init(function, priority)                                  \
+static void __attribute__((constructor)) qemu_init_ ## function(void) {  \
+   register_module_init(function, priority);                             \
+}
+
+#define module_exit(function, priority)                                  \
+static void __attribute__((constructor)) qemu_exit_ ## function(void) {  \
+   register_module_exit(function, priority);                             \
+}
+
+#define MOD_PRI_HIGHEST    0
+#define MOD_PRI_BLOCK      (MOD_PRI_HIGHEST + 1)
+
+#define block_init(function) module_init(function, MOD_PRI_BLOCK)
+#define block_exit(function) module_exit(function, MOD_PRI_BLOCK)
+
+void register_module_init(int (*fn)(void), int priority);
+
+void register_module_exit(void (*fn)(void), int priority);
+
+int module_call_init(int priority);
+
+void module_call_exit(int priority);
+
+#endif
diff --git a/rules.mak b/rules.mak
index a75a93b..8471d40 100644
--- a/rules.mak
+++ b/rules.mak
@@ -8,10 +8,13 @@
 %.o: %.m
 	$(call quiet-command,$(CC) $(CFLAGS) $(CPPFLAGS) -c -o $@ $<,"  OBJC  $(TARGET_DIR)$@")
 
-LINK = $(call quiet-command,$(CC) $(LDFLAGS) -o $@ $^ $(LIBS),"  LINK  $(TARGET_DIR)$@")
+WAS=-Wl,--whole-archive
+WAE=-Wl,--no-whole-archive
+
+LINK = $(call quiet-command,$(CC) $(LDFLAGS) -o $@ $(1) $(LIBS) $(WAS) $(ARLIBS) $(WAE),"  LINK  $(TARGET_DIR)$@")
 
 %$(EXESUF): %.o
-	$(LINK)
+	$(call LINK,$^)
 
 %.a:
 	$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^,"  AR    $(TARGET_DIR)$@")
-- 
1.6.0.6