Implement symbol hiding for JSC's JIT functions.

These functions are implemented directly in assembly, so they need the
proper directives to enable/disable visibility. On ELF systems, it's
.hidden, whereas on Mach-O systems (Mac) it's .private_extern. On
Windows, it's not necessary since you have to explicitly export. I
also implemented the AIX idiom, though it's unlikely anyone will
implement AIX/POWER JIT.

That leaves only HP-UX on PA-RISC unimplemented, from the platforms
that Qt supports. It's also unlikely that we'll imlpement JIT for it.

Reviewed-by: Kent Hansen

1 files changed, 23 insertions, 0 deletions

diff --git a/src/3rdparty/webkit/JavaScriptCore/jit/JITStubs.cpp b/src/3rdparty/webkit/JavaScriptCore/jit/JITStubs.cpp
index f0d3b84..0eb0799 100644
--- a/src/3rdparty/webkit/JavaScriptCore/jit/JITStubs.cpp
+++ b/src/3rdparty/webkit/JavaScriptCore/jit/JITStubs.cpp
@@ -73,6 +73,19 @@ namespace JSC {
 #define SYMBOL_STRING(name) #name
 #endif
 
+#if PLATFORM(DARWIN)
+    // Mach-O platform
+#define HIDE_SYMBOL(name) ".private_extern _" #name
+#elif PLATFORM(AIX)
+    // IBM's own file format
+#define HIDE_SYMBOL(name) ".lglobl " #name
+#elif PLATFORM(LINUX) || PLATFORM(FREEBSD) || PLATFORM(OPENBSD) || PLATFORM(SOLARIS) || (PLATFORM(HPUX) && PLATFORM(IA64)) || PLATFORM(SYMBIAN) || PLATFORM(NETBSD)
+    // ELF platform
+#define HIDE_SYMBOL(name) ".hidden " #name
+#else
+#define HIDE_SYMBOL(name)
+#endif
+
 #if COMPILER(GCC) && PLATFORM(X86)
 
 // These ASSERTs remind you that, if you change the layout of JITStackFrame, you
@@ -83,6 +96,7 @@ COMPILE_ASSERT(offsetof(struct JITStackFrame, savedEBX) == 0x1c, JITStackFrame_s
 
 asm volatile (
 ".globl " SYMBOL_STRING(ctiTrampoline) "\n"
+HIDE_SYMBOL(ctiTrampoline) "\n"
 SYMBOL_STRING(ctiTrampoline) ":" "\n"
     "pushl %ebp" "\n"
     "movl %esp, %ebp" "\n"
@@ -103,6 +117,7 @@ SYMBOL_STRING(ctiTrampoline) ":" "\n"
 
 asm volatile (
 ".globl " SYMBOL_STRING(ctiVMThrowTrampoline) "\n"
+HIDE_SYMBOL(ctiVMThrowTrampoline) "\n"
 SYMBOL_STRING(ctiVMThrowTrampoline) ":" "\n"
 #if !USE(JIT_STUB_ARGUMENT_VA_LIST)
     "movl %esp, %ecx" "\n"
@@ -118,6 +133,7 @@ SYMBOL_STRING(ctiVMThrowTrampoline) ":" "\n"
     
 asm volatile (
 ".globl " SYMBOL_STRING(ctiOpThrowNotCaught) "\n"
+HIDE_SYMBOL(ctiOpThrowNotCaught) "\n"
 SYMBOL_STRING(ctiOpThrowNotCaught) ":" "\n"
     "addl $0x1c, %esp" "\n"
     "popl %ebx" "\n"
@@ -141,6 +157,7 @@ COMPILE_ASSERT(offsetof(struct JITStackFrame, savedRBX) == 0x48, JITStackFrame_s
 
 asm volatile (
 ".globl " SYMBOL_STRING(ctiTrampoline) "\n"
+HIDE_SYMBOL(ctiTrampoline) "\n"
 SYMBOL_STRING(ctiTrampoline) ":" "\n"
     "pushq %rbp" "\n"
     "movq %rsp, %rbp" "\n"
@@ -167,6 +184,7 @@ SYMBOL_STRING(ctiTrampoline) ":" "\n"
 
 asm volatile (
 ".globl " SYMBOL_STRING(ctiVMThrowTrampoline) "\n"
+HIDE_SYMBOL(ctiVMThrowTrampoline) "\n"
 SYMBOL_STRING(ctiVMThrowTrampoline) ":" "\n"
     "movq %rsp, %rdi" "\n"
     "call " SYMBOL_STRING(cti_vm_throw) "\n"
@@ -182,6 +200,7 @@ SYMBOL_STRING(ctiVMThrowTrampoline) ":" "\n"
 
 asm volatile (
 ".globl " SYMBOL_STRING(ctiOpThrowNotCaught) "\n"
+HIDE_SYMBOL(ctiOpThrowNotCaught) "\n"
 SYMBOL_STRING(ctiOpThrowNotCaught) ":" "\n"
     "addq $0x48, %rsp" "\n"
     "popq %rbx" "\n"
@@ -203,6 +222,7 @@ asm volatile (
 ".text" "\n"
 ".align 2" "\n"
 ".globl " SYMBOL_STRING(ctiTrampoline) "\n"
+HIDE_SYMBOL(ctiTrampoline) "\n"
 ".thumb" "\n"
 ".thumb_func " SYMBOL_STRING(ctiTrampoline) "\n"
 SYMBOL_STRING(ctiTrampoline) ":" "\n"
@@ -229,6 +249,7 @@ asm volatile (
 ".text" "\n"
 ".align 2" "\n"
 ".globl " SYMBOL_STRING(ctiVMThrowTrampoline) "\n"
+HIDE_SYMBOL(ctiVMThrowTrampoline) "\n"
 ".thumb" "\n"
 ".thumb_func " SYMBOL_STRING(ctiVMThrowTrampoline) "\n"
 SYMBOL_STRING(ctiVMThrowTrampoline) ":" "\n"
@@ -246,6 +267,7 @@ asm volatile (
 ".text" "\n"
 ".align 2" "\n"
 ".globl " SYMBOL_STRING(ctiOpThrowNotCaught) "\n"
+HIDE_SYMBOL(ctiOpThrowNotCaught) "\n"
 ".thumb" "\n"
 ".thumb_func " SYMBOL_STRING(ctiOpThrowNotCaught) "\n"
 SYMBOL_STRING(ctiOpThrowNotCaught) ":" "\n"
@@ -591,6 +613,7 @@ namespace JITStubs {
         ".text" "\n" \
         ".align 2" "\n" \
         ".globl " SYMBOL_STRING(cti_##op) "\n" \
+        HIDE_SYMBOL(cti_##op) "\n"             \
         ".thumb" "\n" \
         ".thumb_func " SYMBOL_STRING(cti_##op) "\n" \
         SYMBOL_STRING(cti_##op) ":" "\n" \