Set noinline attribute on exported shim layer functions.

base/allocator/allocator_shim_override_glibc_weak_symbols.h

Index: base/allocator/allocator_shim_override_glibc_weak_symbols.h
diff --git a/base/allocator/allocator_shim_override_glibc_weak_symbols.h b/base/allocator/allocator_shim_override_glibc_weak_symbols.h
index b1296369c1ec123aa101b0e10164244420252808..7f50ac81c308404cb7d4a6ad2b2bce084316dca8 100644
--- a/base/allocator/allocator_shim_override_glibc_weak_symbols.h
+++ b/base/allocator/allocator_shim_override_glibc_weak_symbols.h
@@ -56,23 +56,21 @@ void* GlibcMemalignHook(size_t align, size_t size, const void* caller) {
 
 }  // namespace
 
-SHIM_ALWAYS_EXPORT void* (*MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(
-    size_t,
-    const void*) = &GlibcMallocHook;
-
-SHIM_ALWAYS_EXPORT void* (*MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(
-    void*,
-    size_t,
-    const void*) = &GlibcReallocHook;
-
-SHIM_ALWAYS_EXPORT void (*MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*,
-                                                                  const void*) =
-    &GlibcFreeHook;
-
-SHIM_ALWAYS_EXPORT void* (*MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(
-    size_t,
-    size_t,
-    const void*) = &GlibcMemalignHook;
+__attribute__((visibility("default"))) void* (

[Primiano Tucci (use gerrit), 2017/03/15 11:42:59]

Why are you changing this?
If is just about performance I wouldn't bother doing this.
These hooks are really safety belts for very odd code that we should hit
extremely rarely.
The reason of this entire file is an ancient bug about some RedHat6 libraries
that were relying directly on __glibc_malloc (so bypassing the malloc() symbol
redefinition).
i just didn't feel brave enough to take the risk of finding out if the bug was
fixed and just kept these functions when writing the shim.

In other words, I don't think anybody would realize even if you put a
usleep(50000) here :)

+    *MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t,
+                                               const void*) = &GlibcMallocHook;
+
+__attribute__((visibility("default"))) void* (
+    *MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*) =
+    &GlibcReallocHook;
+
+__attribute__((visibility("default"))) void (
+    *MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*,
+                                             const void*) = &GlibcFreeHook;
+
+__attribute__((visibility("default"))) void* (
+    *MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(size_t, size_t, const void*) =
+    &GlibcMemalignHook;
 
 // 2) Redefine libc symbols themselves.