diff --git a/build-aux/mock-noinline.pl b/build-aux/mock-noinline.pl
index eafe20d2e2e8ac0254f264ba1fc29af536aa81fa..2745d4baf7eb7eaeb8370da2ebeed18d8399c827 100644
--- a/build-aux/mock-noinline.pl
+++ b/build-aux/mock-noinline.pl
@@ -43,7 +43,7 @@ sub scan_annotations {
         } elsif (/^\s*$/) {
             $func = undef;
         }
-        if (/ATTRIBUTE_NOINLINE/) {
+        if (/ATTRIBUTE_MOCKABLE/) {
             if (defined $func) {
                 $noninlined{$func} = 1;
             }
diff --git a/src/check-symfile.pl b/src/check-symfile.pl
index d59a213eba08dde6e12e07357b7219835b2b392b..3b062d0a4865ace25f966bc675f33817f7e5d9ae 100755
--- a/src/check-symfile.pl
+++ b/src/check-symfile.pl
@@ -52,7 +52,7 @@ foreach my $elflib (@elflibs) {
     open NM, "-|", "nm", $elflib or die "cannot run 'nm $elflib': $!";
 
     while (<NM>) {
-        next unless /^\S+\s(?:[TBD])\s(\S+)\s*$/;
+        next unless /^\S+\s(?:[TBDW])\s(\S+)\s*$/;
 
         $gotsyms{$1} = 1;
     }
diff --git a/src/internal.h b/src/internal.h
index c29f20f0221e7eb3a011fc3d5f73dc339f6f4374..00edd4fdeb1f399908cf521b463d2ae6561fc833 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -113,13 +113,26 @@
 # endif
 
 /**
- * ATTRIBUTE_NOINLINE:
+ * ATTRIBUTE_MOCKABLE:
+ *
+ * Ensure that the symbol can be overridden in a mock
+ * library preload. This implies a number of attributes
+ *
+ *  - noinline: prevents the body being inlined to
+ *              callers,
+ *  - noclone: prevents specialized copies of the
+ *             function body being created for different
+ *             callers
+ *  - weak: prevents the compiler making optimizations
+ *          such as constant return value propagation
  *
- * Force compiler not to inline a method. Should be used if
- * the method need to be overridable by test mocks.
  */
-# ifndef ATTRIBUTE_NOINLINE
-#  define ATTRIBUTE_NOINLINE __attribute__((__noinline__))
+# ifndef ATTRIBUTE_MOCKABLE
+#  if __GNUC_PREREQ(4, 5)
+#   define ATTRIBUTE_MOCKABLE __attribute__((__noinline__, __noclone__, __weak__))
+#  else
+#   define ATTRIBUTE_MOCKABLE __attribute__((__noinline__, __weak__))
+#  endif
 # endif
 
 /**
diff --git a/src/qemu/qemu_capspriv.h b/src/qemu/qemu_capspriv.h
index 94fa75b96016d1f8ffa2f739b7ab1e91e7591f2f..6cc189e4034f1a4b329572220ea872083d59f6ad 100644
--- a/src/qemu/qemu_capspriv.h
+++ b/src/qemu/qemu_capspriv.h
@@ -95,7 +95,7 @@ virQEMUCapsSetCPUModelInfo(virQEMUCapsPtr qemuCaps,
 virCPUDefPtr
 virQEMUCapsProbeHostCPUForEmulator(virCapsPtr caps,
                                    virQEMUCapsPtr qemuCaps,
-                                   virDomainVirtType type) ATTRIBUTE_NOINLINE;
+                                   virDomainVirtType type) ATTRIBUTE_MOCKABLE;
 
 void
 virQEMUCapsSetGICCapabilities(virQEMUCapsPtr qemuCaps,
diff --git a/src/rpc/virnetsocket.h b/src/rpc/virnetsocket.h
index de795af9170bda49f195b103b3fa5b2620370e49..3c2945e4b12c254d791b0e083813aa560142dccd 100644
--- a/src/rpc/virnetsocket.h
+++ b/src/rpc/virnetsocket.h
@@ -137,10 +137,10 @@ int virNetSocketGetUNIXIdentity(virNetSocketPtr sock,
                                 gid_t *gid,
                                 pid_t *pid,
                                 unsigned long long *timestamp)
-    ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_MOCKABLE;
 int virNetSocketGetSELinuxContext(virNetSocketPtr sock,
                                   char **context)
-    ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_MOCKABLE;
 
 int virNetSocketSetBlocking(virNetSocketPtr sock,
                             bool blocking);
diff --git a/src/util/vircommand.h b/src/util/vircommand.h
index e7c2e513bae15651fc29f317049be4686e4063b8..c042a532a4835ea9738e20df33e18ad6d853b631 100644
--- a/src/util/vircommand.h
+++ b/src/util/vircommand.h
@@ -58,7 +58,7 @@ enum {
 
 void virCommandPassFD(virCommandPtr cmd,
                       int fd,
-                      unsigned int flags) ATTRIBUTE_NOINLINE;
+                      unsigned int flags) ATTRIBUTE_MOCKABLE;
 
 void virCommandPassListenFDs(virCommandPtr cmd);
 
diff --git a/src/util/vircrypto.h b/src/util/vircrypto.h
index 068602f5dfc435b48dcb43c5eabc070c27c15536..50400c6a1895592515ca69fd21a881feb5b0c9e8 100644
--- a/src/util/vircrypto.h
+++ b/src/util/vircrypto.h
@@ -55,6 +55,6 @@ int virCryptoEncryptData(virCryptoCipher algorithm,
     ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(6)
     ATTRIBUTE_NONNULL(8) ATTRIBUTE_NONNULL(9) ATTRIBUTE_RETURN_CHECK;
 
-uint8_t *virCryptoGenerateRandom(size_t nbytes) ATTRIBUTE_NOINLINE;
+uint8_t *virCryptoGenerateRandom(size_t nbytes) ATTRIBUTE_MOCKABLE;
 
 #endif /* __VIR_CRYPTO_H__ */
diff --git a/src/util/virfile.h b/src/util/virfile.h
index 57ceb807210c01358c7f057a3e37117c200db355..32c9115f57d30c7362ee0d90f94301ffed41db8b 100644
--- a/src/util/virfile.h
+++ b/src/util/virfile.h
@@ -188,7 +188,7 @@ void virFileActivateDirOverride(const char *argv0)
 
 off_t virFileLength(const char *path, int fd) ATTRIBUTE_NONNULL(1);
 bool virFileIsDir (const char *file) ATTRIBUTE_NONNULL(1);
-bool virFileExists(const char *file) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NOINLINE;
+bool virFileExists(const char *file) ATTRIBUTE_NONNULL(1) ATTRIBUTE_MOCKABLE;
 bool virFileIsExecutable(const char *file) ATTRIBUTE_NONNULL(1);
 
 enum {
diff --git a/src/util/virhostcpu.h b/src/util/virhostcpu.h
index 67033de8422bbc7b3ec69ad7891a00e0d1a6c2c0..3b30a0d16cd2b24b2f58f0b071764851d78a9fb1 100644
--- a/src/util/virhostcpu.h
+++ b/src/util/virhostcpu.h
@@ -38,7 +38,7 @@ bool virHostCPUHasBitmap(void);
 virBitmapPtr virHostCPUGetPresentBitmap(void);
 virBitmapPtr virHostCPUGetOnlineBitmap(void);
 int virHostCPUGetCount(void);
-int virHostCPUGetThreadsPerSubcore(virArch arch) ATTRIBUTE_NOINLINE;
+int virHostCPUGetThreadsPerSubcore(virArch arch) ATTRIBUTE_MOCKABLE;
 
 int virHostCPUGetMap(unsigned char **cpumap,
                      unsigned int *online,
@@ -51,7 +51,7 @@ int virHostCPUGetInfo(virArch hostarch,
                       unsigned int *cores,
                       unsigned int *threads);
 
-int virHostCPUGetKVMMaxVCPUs(void) ATTRIBUTE_NOINLINE;
+int virHostCPUGetKVMMaxVCPUs(void) ATTRIBUTE_MOCKABLE;
 
 int virHostCPUStatsAssign(virNodeCPUStatsPtr param,
                           const char *name,
diff --git a/src/util/virmacaddr.h b/src/util/virmacaddr.h
index f4f5e2ce117288f7b5ee5f72be92dc646e786214..79492cdf3f150eade8874e93db86a91a6818ae37 100644
--- a/src/util/virmacaddr.h
+++ b/src/util/virmacaddr.h
@@ -48,7 +48,7 @@ void virMacAddrGetRaw(const virMacAddr *src, unsigned char dst[VIR_MAC_BUFLEN]);
 const char *virMacAddrFormat(const virMacAddr *addr,
                              char *str);
 void virMacAddrGenerate(const unsigned char prefix[VIR_MAC_PREFIX_BUFLEN],
-                        virMacAddrPtr addr) ATTRIBUTE_NOINLINE;
+                        virMacAddrPtr addr) ATTRIBUTE_MOCKABLE;
 int virMacAddrParse(const char* str,
                     virMacAddrPtr addr) ATTRIBUTE_RETURN_CHECK;
 int virMacAddrParseHex(const char* str,
diff --git a/src/util/virnetdev.h b/src/util/virnetdev.h
index 51fcae544e89421fffccc1e34dd745698f247be0..2e9a9c4057ad1a1aa6c7d13e4f0f845342298219 100644
--- a/src/util/virnetdev.h
+++ b/src/util/virnetdev.h
@@ -156,7 +156,7 @@ int virNetDevExists(const char *brname)
 
 int virNetDevSetOnline(const char *ifname,
                        bool online)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 int virNetDevGetOnline(const char *ifname,
                       bool *online)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
@@ -164,7 +164,7 @@ int virNetDevGetOnline(const char *ifname,
 
 int virNetDevSetMAC(const char *ifname,
                     const virMacAddr *macaddr)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 int virNetDevGetMAC(const char *ifname,
                     virMacAddrPtr macaddr)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
@@ -303,8 +303,8 @@ int virNetDevSysfsFile(char **pf_sysfs_device_link,
                        const char *ifname,
                        const char *file)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
-    ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 
 int virNetDevRunEthernetScript(const char *ifname, const char *script)
-    ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_MOCKABLE;
 #endif /* __VIR_NETDEV_H__ */
diff --git a/src/util/virnetdevip.h b/src/util/virnetdevip.h
index 6b509ea445ac204782ce50bf505a156474e0020b..972a49ae8f1a422d52be5f1b3f96231bba9e3ef0 100644
--- a/src/util/virnetdevip.h
+++ b/src/util/virnetdevip.h
@@ -67,7 +67,7 @@ int virNetDevIPAddrAdd(const char *ifname,
                        virSocketAddr *addr,
                        virSocketAddr *peer,
                        unsigned int prefix)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 int virNetDevIPRouteAdd(const char *ifname,
                         virSocketAddrPtr addr,
                         unsigned int prefix,
diff --git a/src/util/virnetdevopenvswitch.h b/src/util/virnetdevopenvswitch.h
index 51bb1dd006b9e2e6328925b2f2bb5131136b3ccf..dc677ca0248c1e9317ae4bb0fc26d12a62f102bf 100644
--- a/src/util/virnetdevopenvswitch.h
+++ b/src/util/virnetdevopenvswitch.h
@@ -59,6 +59,6 @@ int virNetDevOpenvswitchInterfaceStats(const char *ifname,
 
 int virNetDevOpenvswitchGetVhostuserIfname(const char *path,
                                            char **ifname)
-    ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 
 #endif /* __VIR_NETDEV_OPENVSWITCH_H__ */
diff --git a/src/util/virnetdevtap.h b/src/util/virnetdevtap.h
index 0b17feb8d94d0306598f8de8247fca251c235ade..1c4343ef80373ef0bd1e43f918bab690683028f1 100644
--- a/src/util/virnetdevtap.h
+++ b/src/util/virnetdevtap.h
@@ -39,7 +39,7 @@ int virNetDevTapCreate(char **ifname,
                        int *tapfd,
                        size_t tapfdSize,
                        unsigned int flags)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 
 int virNetDevTapDelete(const char *ifname,
                        const char *tunpath)
@@ -49,7 +49,7 @@ int virNetDevTapGetName(int tapfd, char **ifname)
     ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
 
 char* virNetDevTapGetRealDeviceName(char *ifname)
-      ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+      ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 
 typedef enum {
    VIR_NETDEV_TAP_CREATE_NONE = 0,
@@ -89,7 +89,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
                                    unsigned int *actualMTU,
                                    unsigned int flags)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
-    ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
 
 int virNetDevTapInterfaceStats(const char *ifname,
                                virDomainInterfaceStatsPtr stats)
diff --git a/src/util/virnuma.h b/src/util/virnuma.h
index e4e1fd0b9755989d590312096a72f0837e3ce5e7..62b89e9cb7b07a8f048176c4cf4ca344dcf11a03 100644
--- a/src/util/virnuma.h
+++ b/src/util/virnuma.h
@@ -34,20 +34,20 @@ int virNumaSetupMemoryPolicy(virDomainNumatuneMemMode mode,
                              virBitmapPtr nodeset);
 
 virBitmapPtr virNumaGetHostMemoryNodeset(void);
-bool virNumaNodesetIsAvailable(virBitmapPtr nodeset) ATTRIBUTE_NOINLINE;
-bool virNumaIsAvailable(void) ATTRIBUTE_NOINLINE;
-int virNumaGetMaxNode(void) ATTRIBUTE_NOINLINE;
-bool virNumaNodeIsAvailable(int node) ATTRIBUTE_NOINLINE;
+bool virNumaNodesetIsAvailable(virBitmapPtr nodeset) ATTRIBUTE_MOCKABLE;
+bool virNumaIsAvailable(void) ATTRIBUTE_MOCKABLE;
+int virNumaGetMaxNode(void) ATTRIBUTE_MOCKABLE;
+bool virNumaNodeIsAvailable(int node) ATTRIBUTE_MOCKABLE;
 int virNumaGetDistances(int node,
                         int **distances,
-                        int *ndistances) ATTRIBUTE_NOINLINE;
+                        int *ndistances) ATTRIBUTE_MOCKABLE;
 int virNumaGetNodeMemory(int node,
                          unsigned long long *memsize,
-                         unsigned long long *memfree) ATTRIBUTE_NOINLINE;
+                         unsigned long long *memfree) ATTRIBUTE_MOCKABLE;
 
 unsigned int virNumaGetMaxCPUs(void);
 
-int virNumaGetNodeCPUs(int node, virBitmapPtr *cpus) ATTRIBUTE_NOINLINE;
+int virNumaGetNodeCPUs(int node, virBitmapPtr *cpus) ATTRIBUTE_MOCKABLE;
 
 int virNumaGetPageInfo(int node,
                        unsigned int page_size,
@@ -59,7 +59,7 @@ int virNumaGetPages(int node,
                     unsigned int **pages_avail,
                     unsigned int **pages_free,
                     size_t *npages)
-    ATTRIBUTE_NONNULL(5) ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(5) ATTRIBUTE_MOCKABLE;
 int virNumaSetPagePoolSize(int node,
                            unsigned int page_size,
                            unsigned long long page_count,
diff --git a/src/util/virrandom.h b/src/util/virrandom.h
index 7a984ee7b09eb3705f63c4eff256ccadeaa9f348..990a456addf7da62467a259692b83af84482a4c4 100644
--- a/src/util/virrandom.h
+++ b/src/util/virrandom.h
@@ -24,11 +24,11 @@
 
 # include "internal.h"
 
-uint64_t virRandomBits(int nbits) ATTRIBUTE_NOINLINE;
+uint64_t virRandomBits(int nbits) ATTRIBUTE_MOCKABLE;
 double virRandom(void);
 uint32_t virRandomInt(uint32_t max);
 int virRandomBytes(unsigned char *buf, size_t buflen)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
-int virRandomGenerateWWN(char **wwn, const char *virt_type) ATTRIBUTE_NOINLINE;
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_MOCKABLE;
+int virRandomGenerateWWN(char **wwn, const char *virt_type) ATTRIBUTE_MOCKABLE;
 
 #endif /* __VIR_RANDOM_H__ */
diff --git a/src/util/virscsi.h b/src/util/virscsi.h
index 9f8b3ecf1e6409f941b9d2ff07e8d318ee3f5c75..eed563d6c7729c3a4abd688594fe7d5448ee359f 100644
--- a/src/util/virscsi.h
+++ b/src/util/virscsi.h
@@ -37,7 +37,7 @@ char *virSCSIDeviceGetSgName(const char *sysfs_prefix,
                              const char *adapter,
                              unsigned int bus,
                              unsigned int target,
-                             unsigned long long unit) ATTRIBUTE_NOINLINE;
+                             unsigned long long unit) ATTRIBUTE_MOCKABLE;
 char *virSCSIDeviceGetDevName(const char *sysfs_prefix,
                               const char *adapter,
                               unsigned int bus,
diff --git a/src/util/virscsivhost.h b/src/util/virscsivhost.h
index 21887ddbd5d49500b4c427bed19c18e58872edd2..f9272a659f577989da8b1f596b35a1186b381a97 100644
--- a/src/util/virscsivhost.h
+++ b/src/util/virscsivhost.h
@@ -61,6 +61,6 @@ void virSCSIVHostDeviceGetUsedBy(virSCSIVHostDevicePtr dev,
                                  const char **drv_name,
                                  const char **dom_name);
 void virSCSIVHostDeviceFree(virSCSIVHostDevicePtr dev);
-int virSCSIVHostOpenVhostSCSI(int *vhostfd) ATTRIBUTE_NOINLINE;
+int virSCSIVHostOpenVhostSCSI(int *vhostfd) ATTRIBUTE_MOCKABLE;
 
 #endif /* __VIR_SCSIHOST_H__ */
diff --git a/src/util/virtpm.h b/src/util/virtpm.h
index b21fc0532f8df09b37073b15462bab212d4d4d41..7067bb53dedccebdf717a9d79947e9c1b3865e1d 100644
--- a/src/util/virtpm.h
+++ b/src/util/virtpm.h
@@ -22,6 +22,6 @@
 #ifndef __VIR_TPM_H__
 # define __VIR_TPM_H__
 
-char *virTPMCreateCancelPath(const char *devpath) ATTRIBUTE_NOINLINE;
+char *virTPMCreateCancelPath(const char *devpath) ATTRIBUTE_MOCKABLE;
 
 #endif /* __VIR_TPM_H__ */
diff --git a/src/util/virutil.h b/src/util/virutil.h
index 49382557f6d6292c8bda5087b8c096bd0f246dd3..35e5ca3ab64891eeb77c413dc8b1c29ef3317830 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -139,8 +139,8 @@ char *virGetUserConfigDirectory(void);
 char *virGetUserCacheDirectory(void);
 char *virGetUserRuntimeDirectory(void);
 char *virGetUserShell(uid_t uid);
-char *virGetUserName(uid_t uid) ATTRIBUTE_NOINLINE;
-char *virGetGroupName(gid_t gid) ATTRIBUTE_NOINLINE;
+char *virGetUserName(uid_t uid) ATTRIBUTE_MOCKABLE;
+char *virGetGroupName(gid_t gid) ATTRIBUTE_MOCKABLE;
 int virGetGroupList(uid_t uid, gid_t group, gid_t **groups)
     ATTRIBUTE_NONNULL(3);
 int virGetUserID(const char *name,
@@ -201,12 +201,12 @@ verify((int)VIR_TRISTATE_BOOL_ABSENT == (int)VIR_TRISTATE_SWITCH_ABSENT);
 
 unsigned int virGetListenFDs(void);
 
-long virGetSystemPageSize(void) ATTRIBUTE_NOINLINE;
-long virGetSystemPageSizeKB(void) ATTRIBUTE_NOINLINE;
+long virGetSystemPageSize(void) ATTRIBUTE_MOCKABLE;
+long virGetSystemPageSizeKB(void) ATTRIBUTE_MOCKABLE;
 
 unsigned long long virMemoryLimitTruncate(unsigned long long value);
 bool virMemoryLimitIsSet(unsigned long long value);
-unsigned long long virMemoryMaxValue(bool ulong) ATTRIBUTE_NOINLINE;
+unsigned long long virMemoryMaxValue(bool ulong) ATTRIBUTE_MOCKABLE;
 
 /**
  * VIR_ASSIGN_IS_OVERFLOW:
diff --git a/src/util/viruuid.h b/src/util/viruuid.h
index 1d67e9ee57ea4276ea2806a6ca59549827c7e9b8..3b41b4205087bf88040980a073950504e7fdf829 100644
--- a/src/util/viruuid.h
+++ b/src/util/viruuid.h
@@ -49,7 +49,7 @@ int virGetHostUUID(unsigned char *host_uuid) ATTRIBUTE_NONNULL(1);
 
 int virUUIDIsValid(unsigned char *uuid);
 
-int virUUIDGenerate(unsigned char *uuid) ATTRIBUTE_NOINLINE;
+int virUUIDGenerate(unsigned char *uuid) ATTRIBUTE_MOCKABLE;
 
 int virUUIDParse(const char *uuidstr,
                  unsigned char *uuid)