Compile with -fvisibility=hidden

- Produce smaller and faster code, especially for access to static and thread-local variables
- Fix a return value corruption in Unix RhpCheckedLockCmpXchg and RhpCheckedXchg helpers.

9 files changed, 33 insertions, 52 deletions

diff --git a/src/Native/CMakeLists.txt b/src/Native/CMakeLists.txt
index fe648a769..b7d400b1c 100644
--- a/src/Native/CMakeLists.txt
+++ b/src/Native/CMakeLists.txt
@@ -79,6 +79,7 @@ if (CLR_CMAKE_PLATFORM_UNIX)
     add_compile_options(-fms-extensions)
 
     add_compile_options(-fPIC)
+    add_compile_options(-fvisibility=hidden)
 endif(CLR_CMAKE_PLATFORM_UNIX)
 
 if(CLR_CMAKE_PLATFORM_UNIX_TARGET_ARM)
diff --git a/src/Native/Runtime/amd64/WriteBarriers.S b/src/Native/Runtime/amd64/WriteBarriers.S
index e2f226a1b..3da2b6f21 100644
--- a/src/Native/Runtime/amd64/WriteBarriers.S
+++ b/src/Native/Runtime/amd64/WriteBarriers.S
@@ -15,8 +15,7 @@
 	.endif
 
     // If g_GCShadow is 0, don't perform the check.
-    PREPARE_EXTERNAL_VAR g_GCShadow, rax
-    cmp     qword ptr [rax], 0
+    cmp     qword ptr [C_VAR(g_GCShadow)], 0
     je      \BASENAME\()_UpdateShadowHeap_Done_\REFREG
 
     // Save DESTREG since we're about to modify it (and we need the original value both within the macro and
@@ -31,13 +30,10 @@
     push    \DESTREG
 
     // Transform DESTREG into the equivalent address in the shadow heap.
-    PREPARE_EXTERNAL_VAR g_lowest_address, rax
-    sub     \DESTREG, [rax]
+    sub     \DESTREG, [C_VAR(g_lowest_address)]
     jb      \BASENAME\()_UpdateShadowHeap_PopThenDone_\REFREG
-    PREPARE_EXTERNAL_VAR g_GCShadow, rax
-    add     \DESTREG, [rax]
-    PREPARE_EXTERNAL_VAR g_GCShadowEnd, rax
-    cmp     \DESTREG, [rax]
+    add     \DESTREG, [C_VAR(g_GCShadow)]
+    cmp     \DESTREG, [C_VAR(g_GCShadowEnd)]
     ja      \BASENAME\()_UpdateShadowHeap_PopThenDone_\REFREG
 
     // Update the shadow heap.
@@ -95,11 +91,9 @@
 
     // If the reference is to an object that's not in an ephemeral generation we have no need to track it
     // (since the object won't be collected or moved by an ephemeral collection).
-    PREPARE_EXTERNAL_VAR g_ephemeral_low, rax
-    cmp     \REFREG, [rax]
+    cmp     \REFREG, [C_VAR(g_ephemeral_low)]
     jb      \BASENAME\()_NoBarrierRequired_\REFREG
-    PREPARE_EXTERNAL_VAR g_ephemeral_high, rax
-    cmp     \REFREG, [rax]
+    cmp     \REFREG, [C_VAR(g_ephemeral_high)]
     jae     \BASENAME\()_NoBarrierRequired_\REFREG
 
     // We have a location on the GC heap being updated with a reference to an ephemeral object so we must
@@ -107,8 +101,7 @@
     // an entire byte in the card table since it's quicker than messing around with bitmasks and we only write
     // the byte if it hasn't already been done since writes are expensive and impact scaling.
     shr     rdi, 11
-    PREPARE_EXTERNAL_VAR g_card_table, rax
-    add     rdi, [rax]
+    add     rdi, [C_VAR(g_card_table)]
     cmp     byte ptr [rdi], 0FFh
     jne     \BASENAME\()_UpdateCardTable_\REFREG
 
@@ -167,11 +160,9 @@ DEFINE_UNCHECKED_WRITE_BARRIER RSI, ESI
 
     // The location being updated might not even lie in the GC heap (a handle or stack location for instance),
     // in which case no write barrier is required.
-    PREPARE_EXTERNAL_VAR g_lowest_address, rax
-    cmp     rdi, [rax]
+    cmp     rdi, [C_VAR(g_lowest_address)]
     jb      \BASENAME\()_NoBarrierRequired_\REFREG
-    PREPARE_EXTERNAL_VAR g_highest_address, rax
-    cmp     rdi, [rax]
+    cmp     rdi, [C_VAR(g_highest_address)]
     jae     \BASENAME\()_NoBarrierRequired_\REFREG
 
     DEFINE_UNCHECKED_WRITE_BARRIER_CORE \BASENAME, \REFREG
@@ -262,11 +253,9 @@ LEAF_ENTRY RhpByRefAssignRef, _TEXT
 
     // If the reference is to an object that's not in an ephemeral generation we have no need to track it
     // (since the object won't be collected or moved by an ephemeral collection).
-    PREPARE_EXTERNAL_VAR g_ephemeral_low, rax
-    cmp     rcx, [rax]
+    cmp     rcx, [C_VAR(g_ephemeral_low)]
     jb      RhpByRefAssignRef_NotInHeap
-    PREPARE_EXTERNAL_VAR g_ephemeral_high, rax
-    cmp     rcx, [rax]
+    cmp     rcx, [C_VAR(g_ephemeral_high)]
     jae     RhpByRefAssignRef_NotInHeap
 
     // move current rdi value into rcx and then increment the pointers
@@ -279,8 +268,7 @@ LEAF_ENTRY RhpByRefAssignRef, _TEXT
     // an entire byte in the card table since it's quicker than messing around with bitmasks and we only write
     // the byte if it hasn't already been done since writes are expensive and impact scaling.
     shr     rcx, 11
-    PREPARE_EXTERNAL_VAR g_card_table, rax
-    add     rcx, [rax]
+    add     rcx, [C_VAR(g_card_table)]
     cmp     byte ptr [rcx], 0FFh
     jne     RhpByRefAssignRef_UpdateCardTable
     ret
diff --git a/src/Native/Runtime/unix/unixasmmacrosamd64.inc b/src/Native/Runtime/unix/unixasmmacrosamd64.inc
index 5669aabf6..bb8738c0b 100644
--- a/src/Native/Runtime/unix/unixasmmacrosamd64.inc
+++ b/src/Native/Runtime/unix/unixasmmacrosamd64.inc
@@ -3,6 +3,8 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+#define C_VAR(Name) rip + C_FUNC(Name)
+
 .macro NESTED_ENTRY Name, Section, Handler
         LEAF_ENTRY \Name, \Section
         .ifnc \Handler, NoHandler
@@ -57,16 +59,6 @@ C_FUNC(\Name\()_End):
         .cfi_endproc
 .endm
 
-.macro TAILJMP_RAX
-        .byte 0x48
-        .byte 0xFF
-        .byte 0xE0
-.endm
-
-.macro PREPARE_EXTERNAL_VAR Name, HelperReg
-        mov \HelperReg, [rip + C_FUNC(\Name)@GOTPCREL]
-.endm
-
 .macro push_nonvol_reg Register
         push \Register
         .cfi_adjust_cfa_offset 8
diff --git a/src/Native/jitinterface/CMakeLists.txt b/src/Native/jitinterface/CMakeLists.txt
index 9832cbce7..1dee1e87c 100755
--- a/src/Native/jitinterface/CMakeLists.txt
+++ b/src/Native/jitinterface/CMakeLists.txt
@@ -6,10 +6,6 @@ set(NATIVE_SOURCES
     corinfoexception.cpp
 )
 
-if (WIN32)
-    list(APPEND NATIVE_SOURCES jitinterface.def)
-endif ()
-
 add_library(jitinterface
     SHARED
     ${NATIVE_SOURCES}
diff --git a/src/Native/jitinterface/corinfoexception.cpp b/src/Native/jitinterface/corinfoexception.cpp
index b8e44fab9..c2dd97c7a 100644
--- a/src/Native/jitinterface/corinfoexception.cpp
+++ b/src/Native/jitinterface/corinfoexception.cpp
@@ -4,18 +4,19 @@
 //
 
 #include "corinfoexception.h"
+#include "dllexport.h"
 
-extern "C" CorInfoException* AllocException(const WCHAR* message, int messageLength)
+DLL_EXPORT CorInfoException* AllocException(const WCHAR* message, int messageLength)
 {
     return new CorInfoException(message, messageLength);
 }
 
-extern "C" void FreeException(CorInfoException* pException)
+DLL_EXPORT void FreeException(CorInfoException* pException)
 {
     delete pException;
 }
 
-extern "C" const WCHAR* GetExceptionMessage(const CorInfoException* pException)
+DLL_EXPORT const WCHAR* GetExceptionMessage(const CorInfoException* pException)
 {
     return pException->GetMessage();
 }
diff --git a/src/Native/jitinterface/dllexport.h b/src/Native/jitinterface/dllexport.h
new file mode 100644
index 000000000..3fd5e8989
--- /dev/null
+++ b/src/Native/jitinterface/dllexport.h
@@ -0,0 +1,10 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+#ifdef _WIN32
+#define DLL_EXPORT extern "C" __declspec(dllexport)
+#else
+#define DLL_EXPORT extern "C" __attribute((visibility("default")))
+#endif
diff --git a/src/Native/jitinterface/jitinterface.cpp b/src/Native/jitinterface/jitinterface.cpp
index 7b73f4644..7c04ed30e 100644
--- a/src/Native/jitinterface/jitinterface.cpp
+++ b/src/Native/jitinterface/jitinterface.cpp
@@ -4,6 +4,7 @@
 //
 
 #include "jitinterface.h"
+#include "dllexport.h"
 
 enum CORINFO_RUNTIME_LOOKUP_KIND { };
 struct CORINFO_LOOKUP_KIND
@@ -31,7 +32,7 @@ CORINFO_LOOKUP_KIND JitInterfaceWrapper::getLocationOfThisType(void* context)
 
 static JitInterfaceWrapper instance;
 
-extern "C" void* GetJitInterfaceWrapper(IJitInterface *pCorInfo)
+DLL_EXPORT void* GetJitInterfaceWrapper(IJitInterface *pCorInfo)
 {
     instance._pCorInfo = pCorInfo;
     return &instance;
diff --git a/src/Native/jitinterface/jitinterface.def b/src/Native/jitinterface/jitinterface.def
deleted file mode 100644
index ea19c75fa..000000000
--- a/src/Native/jitinterface/jitinterface.def
+++ /dev/null
@@ -1,9 +0,0 @@
-; Copyright (c) Microsoft. All rights reserved.
-; Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-EXPORTS
-    GetJitInterfaceWrapper
-    JitWrapper
-    AllocException
-    FreeException
-    GetExceptionMessage
diff --git a/src/Native/jitinterface/jitwrapper.cpp b/src/Native/jitinterface/jitwrapper.cpp
index 3da42ace9..3428356d5 100644
--- a/src/Native/jitinterface/jitwrapper.cpp
+++ b/src/Native/jitinterface/jitwrapper.cpp
@@ -4,6 +4,7 @@
 //
 
 #include "corinfoexception.h"
+#include "dllexport.h"
 
 class Jit
 {
@@ -16,7 +17,7 @@ public:
         void* nativeSizeOfCode) = 0;
 };
 
-extern "C" int JitWrapper(
+DLL_EXPORT int JitWrapper(
     CorInfoException **ppException,
     Jit* pJit,
     void* compHnd,