MCJIT-remote: __main should be resolved in child context.

- Mark tests as XFAIL:cygming in test/ExecutionEngine/MCJIT/remote.
    Rather to suppress them, I'd like to leave them running as XFAIL.
  - Revert r193472. RecordMemoryManager no longer resolves __main on cygming.

There are a couple of issues.

  - X86 Codegen emits "call __main" in @main for targeting cygming.
    It is useless in JIT. FYI, tests are passing when emitting __main is disabled.
  - Current remote JIT does not resolve any symbols in child context.

FIXME: __main should be disabled, or remote JIT should resolve __main.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193498 91177308-0d34-0410-b5e6-96231b3b80d8

test/ExecutionEngine/MCJIT/remote/cross-module-a.ll

@@ -1,5 +1,8 @@
 ; RUN: %lli_mcjit -extra-modules=%p/cross-module-b.ir  -disable-lazy-compilation=true -remote-mcjit -mcjit-remote-process=lli-child-target %s > /dev/null
 
+; This fails because __main is not resolved in remote mcjit.
+; XFAIL: cygwin,mingw32
+
 declare i32 @FB()
 
 define i32 @FA() {

test/ExecutionEngine/MCJIT/remote/multi-module-a.ll

@@ -1,5 +1,8 @@
 ; RUN: %lli_mcjit -extra-modules=%p/multi-module-b.ir,%p/multi-module-c.ir  -disable-lazy-compilation=true -remote-mcjit -mcjit-remote-process=lli-child-target %s > /dev/null
 
+; This fails because __main is not resolved in remote mcjit.
+; XFAIL: cygwin,mingw32
+
 declare i32 @FB()
 
 define i32 @main() {

test/ExecutionEngine/MCJIT/remote/simpletest-remote.ll

@@ -1,5 +1,7 @@
 ; RUN: %lli_mcjit -remote-mcjit -mcjit-remote-process=lli-child-target %s > /dev/null
-; XFAIL:  mips
+
+; This fails because __main is not resolved in remote mcjit on cygming.
+; XFAIL: cygwin,mingw32,mips
 
 define i32 @bar() {
 	ret i32 0

test/ExecutionEngine/MCJIT/remote/test-common-symbols-remote.ll

@@ -1,5 +1,7 @@
 ; RUN: %lli_mcjit -remote-mcjit -O0 -disable-lazy-compilation=false -mcjit-remote-process=lli-child-target %s
-; XFAIL: mips
+
+; This fails because __main is not resolved in remote mcjit on cygming.
+; XFAIL: cygwin,mingw32,mips
 
 ; The intention of this test is to verify that symbols mapped to COMMON in ELF
 ; work as expected.

test/ExecutionEngine/MCJIT/remote/test-data-align-remote.ll

@@ -1,5 +1,7 @@
 ; RUN:  %lli_mcjit -remote-mcjit -O0 -mcjit-remote-process=lli-child-target %s
-; XFAIL: mips
+
+; This fails because __main is not resolved in remote mcjit on cygming.
+; XFAIL: cygwin,mingw32,mips
 
 ; Check that a variable is always aligned as specified.
 

test/ExecutionEngine/MCJIT/remote/test-fp-no-external-funcs-remote.ll

@@ -1,5 +1,7 @@
 ; RUN: %lli_mcjit -remote-mcjit -mcjit-remote-process=lli-child-target %s > /dev/null
-; XFAIL:  mips
+
+; This fails because __main is not resolved in remote mcjit on cygming.
+; XFAIL: cygwin,mingw32,mips
 
 define double @test(double* %DP, double %Arg) {
 	%D = load double* %DP		; <double> [#uses=1]

test/ExecutionEngine/MCJIT/remote/test-global-init-nonzero-remote.ll

@@ -1,5 +1,7 @@
 ; RUN: %lli_mcjit -remote-mcjit -mcjit-remote-process=lli-child-target %s > /dev/null
-; XFAIL: mips
+
+; This fails because __main is not resolved in remote mcjit on cygming.
+; XFAIL: cygwin,mingw32,mips
 
 @count = global i32 1, align 4
 

test/ExecutionEngine/MCJIT/remote/test-ptr-reloc-remote.ll

@@ -1,5 +1,8 @@
 ; RUN: %lli_mcjit -remote-mcjit -O0 -mcjit-remote-process=lli-child-target %s
 
+; This fails because __main is not resolved in remote mcjit.
+; XFAIL: cygwin,mingw32
+
 @.str = private unnamed_addr constant [6 x i8] c"data1\00", align 1
 @ptr = global i8* getelementptr inbounds ([6 x i8]* @.str, i32 0, i32 0), align 4
 @.str1 = private unnamed_addr constant [6 x i8] c"data2\00", align 1

tools/lli/RemoteMemoryManager.cpp

@@ -204,19 +204,3 @@ uint8_t *RemoteMemoryManager::allocateGlobal(uintptr_t Size, unsigned Alignment)
 void RemoteMemoryManager::deallocateFunctionBody(void *Body) {
   llvm_unreachable("Unexpected!");
 }
-
-static int jit_noop() {
-  return 0;
-}
-
-uint64_t RemoteMemoryManager::getSymbolAddress(const std::string &Name) {
-  // We should not invoke parent's ctors/dtors from generated main()!
-  // On Mingw and Cygwin, the symbol __main is resolved to
-  // callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
-  // (and register wrong callee's dtors with atexit(3)).
-  // We expect ExecutionEngine::runStaticConstructorsDestructors()
-  // is called before ExecutionEngine::runFunctionAsMain() is called.
-  if (Name == "__main") return (uintptr_t)&jit_noop;
-
-  return 0;
-}

tools/lli/RemoteMemoryManager.h

@@ -78,7 +78,7 @@ public:
   // interface does support this, but clients must provide their own
   // mechanism for finding remote symbol addresses.  MCJIT will resolve
   // symbols from Modules it contains.
-  uint64_t getSymbolAddress(const std::string &Name);
+  uint64_t getSymbolAddress(const std::string &Name) { return 0; }
 
   void notifyObjectLoaded(ExecutionEngine *EE, const ObjectImage *Obj);