Bug 1420353 - Change how replace-malloc initializes, part 2. r=njn

Because one entry point is simpler than two, we make replace_init fulfil
both the roles of replace_init and replace_get_bridge.

Note this should be binary compatible with older replace-malloc
libraries, albeit not detecting their bridge (and with the
previous change, they do not register anyways). So loading older
replace-malloc libraries should do nothing, but not crash in awful ways.

--HG--
extra : rebase_source : aaf83e706ee34f45cfa75551a2f0998e5c5b8726

memory/build/malloc_decls.h

@@ -21,13 +21,12 @@
   (MALLOC_FUNCS_MALLOC_BASE | MALLOC_FUNCS_MALLOC_EXTRA)
 #define MALLOC_FUNCS_JEMALLOC 4
 #define MALLOC_FUNCS_INIT 8
-#define MALLOC_FUNCS_BRIDGE 16
-#define MALLOC_FUNCS_ARENA_BASE 32
-#define MALLOC_FUNCS_ARENA_ALLOC 64
+#define MALLOC_FUNCS_ARENA_BASE 16
+#define MALLOC_FUNCS_ARENA_ALLOC 32
 #define MALLOC_FUNCS_ARENA (MALLOC_FUNCS_ARENA_BASE | MALLOC_FUNCS_ARENA_ALLOC)
 #define MALLOC_FUNCS_ALL                                                       \
-  (MALLOC_FUNCS_INIT | MALLOC_FUNCS_BRIDGE | MALLOC_FUNCS_MALLOC |             \
-   MALLOC_FUNCS_JEMALLOC | MALLOC_FUNCS_ARENA)
+  (MALLOC_FUNCS_INIT | MALLOC_FUNCS_MALLOC | MALLOC_FUNCS_JEMALLOC |           \
+   MALLOC_FUNCS_ARENA)
 
 #endif // malloc_decls_h
 
@@ -38,10 +37,7 @@
 
 #ifdef MALLOC_DECL
 #if MALLOC_FUNCS & MALLOC_FUNCS_INIT
-MALLOC_DECL(init, void, malloc_table_t*)
-#endif
-#if MALLOC_FUNCS & MALLOC_FUNCS_BRIDGE
-MALLOC_DECL(get_bridge, struct ReplaceMallocBridge*)
+MALLOC_DECL(init, void, malloc_table_t*, struct ReplaceMallocBridge**)
 #endif
 #if MALLOC_FUNCS & MALLOC_FUNCS_MALLOC_BASE
 MALLOC_DECL(malloc, void*, size_t)

memory/build/mozjemalloc.cpp

@@ -4830,7 +4830,7 @@ static malloc_table_t gReplaceMallocTable = {
 #define MALLOC_DECL(name, return_type, ...)                                    \
   typedef return_type(name##_impl_t)(__VA_ARGS__);                             \
   name##_impl_t* replace_##name = nullptr;
-#define MALLOC_FUNCS (MALLOC_FUNCS_INIT | MALLOC_FUNCS_BRIDGE)
+#define MALLOC_FUNCS MALLOC_FUNCS_INIT
 #include "malloc_decls.h"
 #endif
 
@@ -4878,6 +4878,7 @@ replace_malloc_init_funcs();
 // Below is the malloc implementation overriding jemalloc and calling the
 // replacement functions if they exist.
 static bool gReplaceMallocInitialized = false;
+static ReplaceMallocBridge* gReplaceMallocBridge = nullptr;
 static void
 init()
 {
@@ -4887,7 +4888,7 @@ init()
 #define MALLOC_DECL(name, ...)                                                 \
   replace_##name = REPLACE_MALLOC_GET_FUNC(handle, name);
 
-#define MALLOC_FUNCS (MALLOC_FUNCS_INIT | MALLOC_FUNCS_BRIDGE)
+#define MALLOC_FUNCS MALLOC_FUNCS_INIT
 #include "malloc_decls.h"
   }
 #endif
@@ -4896,7 +4897,7 @@ init()
   // malloc() we'll get an infinite loop.
   gReplaceMallocInitialized = true;
   if (replace_init) {
-    replace_init(&gReplaceMallocTable);
+    replace_init(&gReplaceMallocTable, &gReplaceMallocBridge);
   }
   replace_malloc_init_funcs();
 }
@@ -4919,10 +4920,7 @@ get_bridge(void)
   if (MOZ_UNLIKELY(!gReplaceMallocInitialized)) {
     init();
   }
-  if (MOZ_LIKELY(!replace_get_bridge)) {
-    return nullptr;
-  }
-  return replace_get_bridge();
+  return gReplaceMallocBridge;
 }
 
 // posix_memalign, aligned_alloc, memalign and valloc all implement some kind

memory/build/replace_malloc.h

@@ -19,7 +19,7 @@
 // An initialization function is called before any malloc replacement
 // function, and has the following declaration:
 //
-//   void replace_init(malloc_table_t *)
+//   void replace_init(malloc_table_t*, ReplaceMallocBridge**)
 //
 // The malloc_table_t pointer given to that function is a table containing
 // pointers to the original allocator implementation, so that replacement
@@ -28,9 +28,13 @@
 // If it needs the original implementation, it thus needs a copy of the
 // original table.
 //
+// The ReplaceMallocBridge* pointer is an outparam that allows the
+// replace_init function to return a pointer to its ReplaceMallocBridge
+// (see replace_malloc_bridge.h).
+//
 // The functions to be implemented in the external library are of the form:
 //
-//   void *replace_malloc(size_t size)
+//   void* replace_malloc(size_t size)
 //   {
 //     // Fiddle with the size if necessary.
 //     // orig->malloc doesn't have to be called if the external library
@@ -85,11 +89,11 @@ MOZ_BEGIN_EXTERN_C
 #define MOZ_REPLACE_WEAK
 #endif
 
-// Export replace_init and replace_get_bridge.
+// Export replace_init.
 #define MALLOC_DECL(name, return_type, ...)                                    \
   MOZ_EXPORT return_type replace_##name(__VA_ARGS__) MOZ_REPLACE_WEAK;
 
-#define MALLOC_FUNCS (MALLOC_FUNCS_INIT | MALLOC_FUNCS_BRIDGE)
+#define MALLOC_FUNCS MALLOC_FUNCS_INIT
 #include "malloc_decls.h"
 
 // Define the remaining replace_* functions as not exported.

memory/replace/dmd/DMD.cpp

@@ -1265,18 +1265,13 @@ static void Init(malloc_table_t* aMallocTable);
 } // namespace mozilla
 
 void
-replace_init(malloc_table_t* aMallocTable)
+replace_init(malloc_table_t* aMallocTable, ReplaceMallocBridge** aBridge)
 {
   mozilla::dmd::Init(aMallocTable);
 #define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
 #define MALLOC_DECL(name, ...) aMallocTable->name = replace_ ## name;
 #include "malloc_decls.h"
-}
-
-ReplaceMallocBridge*
-replace_get_bridge()
-{
-  return mozilla::dmd::gDMDBridge;
+  *aBridge = mozilla::dmd::gDMDBridge;
 }
 
 void*

memory/replace/logalloc/LogAlloc.cpp

@@ -74,8 +74,9 @@ class LogAllocBridge : public ReplaceMallocBridge
 };
 
 void
-replace_init(malloc_table_t* aTable)
+replace_init(malloc_table_t* aTable, ReplaceMallocBridge** aBridge)
 {
+  static LogAllocBridge bridge;
   sFuncs = *aTable;
 #define MALLOC_FUNCS MALLOC_FUNCS_MALLOC_BASE
 #define MALLOC_DECL(name, ...) aTable->name = replace_ ## name;
@@ -86,6 +87,7 @@ replace_init(malloc_table_t* aTable)
   aTable->aligned_alloc = replace_aligned_alloc;
   aTable->valloc = replace_valloc;
 #endif
+  *aBridge = &bridge;
 
 #ifndef _WIN32
   /* When another thread has acquired a lock before forking, the child
@@ -168,13 +170,6 @@ replace_init(malloc_table_t* aTable)
   }
 }
 
-ReplaceMallocBridge*
-replace_get_bridge()
-{
-  static LogAllocBridge bridge;
-  return &bridge;
-}
-
 /* Do a simple, text-form, log of all calls to replace-malloc functions.
  * Use locking to guarantee that an allocation that did happen is logged
  * before any other allocation/free happens.

mozglue/build/replace_malloc.mk

@@ -3,5 +3,5 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 ifeq (Darwin_1,$(OS_TARGET)_$(MOZ_REPLACE_MALLOC))
-MK_LDFLAGS = -Wl,-U,_replace_init -Wl,-U,_replace_get_bridge
+MK_LDFLAGS = -Wl,-U,_replace_init
 endif