Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release:

MFC r309142 (by emaste):

Add WITH_LLD_AS_LD build knob

If set it installs LLD as /usr/bin/ld.  LLD (as of version 3.9) is not
capable of linking the world and kernel, but can self-host and link many
substantial applications. GNU ld continues to be used for the world and
kernel build, regardless of how this knob is set.

It is on by default for arm64, and off for all other CPU architectures.

Sponsored by:	The FreeBSD Foundation

MFC r310840:

Reapply 310775, now it also builds correctly if lldb is disabled:

Move llvm-objdump from CLANG_EXTRAS to installed by default

We currently install three tools from binutils 2.17.50: as, ld, and
objdump. Work is underway to migrate to a permissively-licensed
tool-chain, with one goal being the retirement of binutils 2.17.50.

LLVM's llvm-objdump is intended to be compatible with GNU objdump
although it is currently missing some options and may have formatting
differences. Enable it by default for testing and further investigation.
It may later be changed to install as /usr/bin/objdump, it becomes a
fully viable replacement.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D8879

MFC r312855 (by emaste):

Rename LLD_AS_LD to LLD_IS_LD, for consistency with CLANG_IS_CC

Reported by:	Dan McGregor <dan.mcgregor usask.ca>

MFC r313559 | glebius | 2017-02-10 18:34:48 +0100 (Fri, 10 Feb 2017) | 5 lines

Don't check struct rtentry on FreeBSD, it is an internal kernel structure.
On other systems it may be API structure for SIOCADDRT/SIOCDELRT.

Reviewed by:	emaste, dim

MFC r314152 (by jkim):

Remove an assembler flag, which is redundant since r309124.  The upstream
took care of it by introducing a macro NO_EXEC_STACK_DIRECTIVE.

http://llvm.org/viewvc/llvm-project?rev=273500&view=rev

Reviewed by:	dim

MFC r314564:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
4.0.0 (branches/release_40 296509).  The release will follow soon.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Also note that as of 4.0.0, lld should be able to link the base system
on amd64 and aarch64.  See the WITH_LLD_IS_LLD setting in src.conf(5).
Though please be aware that this is work in progress.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/4.0.0/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Jan Beich, Antoine Brodin and Eric Fiselier for
their help.

Relnotes:	yes
Exp-run:	antoine
PR:		215969, 216008

MFC r314708:

For now, revert r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.

We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it.  An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142

Reported by:	mjg

MFC r314795:

Reapply r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

Pull in r296992 from upstream llvm trunk (by Sanjoy Das):

  [SCEV] Decrease the recursion threshold for CompareValueComplexity

  Fixes PR32142.

  r287232 accidentally increased the recursion threshold for
  CompareValueComplexity from 2 to 32.  This change reverses that
  change by introducing a separate flag for CompareValueComplexity's
  threshold.

The latter revision fixes the excessive compile times for skein_block.c.

MFC r314907 | mmel | 2017-03-08 12:40:27 +0100 (Wed, 08 Mar 2017) | 7 lines

Unbreak ARMv6 world.

The new compiler_rt library imported with clang 4.0.0 have several fatal
issues (non-functional __udivsi3 for example) with ARM specific instrict
functions. As temporary workaround, until upstream solve these problems,
disable all thumb[1][2] related feature.

MFC r315016:

Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release.
We were already very close to the last release candidate, so this is a
pretty minor update.

Relnotes:	yes

MFC r316005:

Revert r314907, and pull in r298713 from upstream compiler-rt trunk (by
Weiming Zhao):

  builtins: Select correct code fragments when compiling for Thumb1/Thum2/ARM ISA.

  Summary:
  Value of __ARM_ARCH_ISA_THUMB isn't based on the actual compilation
  mode (-mthumb, -marm), it reflect's capability of given CPU.

  Due to this:
   - use  __tbumb__ and __thumb2__ insteand of __ARM_ARCH_ISA_THUMB
   - use '.thumb' directive consistently  in all affected files
   - decorate all thumb functions using
     DEFINE_COMPILERRT_THUMB_FUNCTION()

  ---------
  Note: This patch doesn't fix broken Thumb1 variant of __udivsi3 !

  Reviewers: weimingz, rengolin, compnerd

  Subscribers: aemerson, dim

  Differential Revision: https://reviews.llvm.org/D30938

Discussed with:	mmel

2 files changed, 120 insertions, 24 deletions

diff --git a/contrib/compiler-rt/lib/interception/interception.h b/contrib/compiler-rt/lib/interception/interception.h
index 9e9aca2..d79fa67 100644
--- a/contrib/compiler-rt/lib/interception/interception.h
+++ b/contrib/compiler-rt/lib/interception/interception.h
@@ -92,8 +92,8 @@ typedef __sanitizer::OFF64_T OFF64_T;
 
 // Just a pair of pointers.
 struct interpose_substitution {
-  const uptr replacement;
-  const uptr original;
+  const __sanitizer::uptr replacement;
+  const __sanitizer::uptr original;
 };
 
 // For a function foo() create a global pair of pointers { wrap_foo, foo } in
@@ -158,10 +158,12 @@ const interpose_substitution substitution_##func_name[] \
     namespace __interception { \
       extern FUNC_TYPE(func) PTR_TO_REAL(func); \
     }
+# define ASSIGN_REAL(dst, src) REAL(dst) = REAL(src)
 #else  // __APPLE__
 # define REAL(x) x
 # define DECLARE_REAL(ret_type, func, ...) \
     extern "C" ret_type func(__VA_ARGS__);
+# define ASSIGN_REAL(x, y)
 #endif  // __APPLE__
 
 #define DECLARE_REAL_AND_INTERCEPTOR(ret_type, func, ...) \
diff --git a/contrib/compiler-rt/lib/interception/interception_win.cc b/contrib/compiler-rt/lib/interception/interception_win.cc
index 8977d59..91abecf 100644
--- a/contrib/compiler-rt/lib/interception/interception_win.cc
+++ b/contrib/compiler-rt/lib/interception/interception_win.cc
@@ -148,10 +148,16 @@ static void InterceptionFailed() {
 }
 
 static bool DistanceIsWithin2Gig(uptr from, uptr target) {
+#if SANITIZER_WINDOWS64
   if (from < target)
     return target - from <= (uptr)0x7FFFFFFFU;
   else
     return from - target <= (uptr)0x80000000U;
+#else
+  // In a 32-bit address space, the address calculation will wrap, so this check
+  // is unnecessary.
+  return true;
+#endif
 }
 
 static uptr GetMmapGranularity() {
@@ -167,6 +173,21 @@ static uptr RoundUpTo(uptr size, uptr boundary) {
 // FIXME: internal_str* and internal_mem* functions should be moved from the
 // ASan sources into interception/.
 
+static size_t _strlen(const char *str) {
+  const char* p = str;
+  while (*p != '\0') ++p;
+  return p - str;
+}
+
+static char* _strchr(char* str, char c) {
+  while (*str) {
+    if (*str == c)
+      return str;
+    ++str;
+  }
+  return nullptr;
+}
+
 static void _memset(void *p, int value, size_t sz) {
   for (size_t i = 0; i < sz; ++i)
     ((char*)p)[i] = (char)value;
@@ -229,10 +250,6 @@ static void WritePadding(uptr from, uptr size) {
   _memset((void*)from, 0xCC, (size_t)size);
 }
 
-static void CopyInstructions(uptr from, uptr to, uptr size) {
-  _memcpy((void*)from, (void*)to, (size_t)size);
-}
-
 static void WriteJumpInstruction(uptr from, uptr target) {
   if (!DistanceIsWithin2Gig(from + kJumpInstructionLength, target))
     InterceptionFailed();
@@ -294,7 +311,7 @@ struct TrampolineMemoryRegion {
   uptr max_size;
 };
 
-static const uptr kTrampolineScanLimitRange = 1 << 30;  // 1 gig
+static const uptr kTrampolineScanLimitRange = 1 << 31;  // 2 gig
 static const int kMaxTrampolineRegion = 1024;
 static TrampolineMemoryRegion TrampolineRegions[kMaxTrampolineRegion];
 
@@ -384,7 +401,7 @@ static uptr AllocateMemoryForTrampoline(uptr image_address, size_t size) {
 }
 
 // Returns 0 on error.
-static size_t GetInstructionSize(uptr address) {
+static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
   switch (*(u64*)address) {
     case 0x90909090909006EB:  // stub: jmp over 6 x nop.
       return 8;
@@ -410,7 +427,6 @@ static size_t GetInstructionSize(uptr address) {
 
     case 0xb8:  // b8 XX XX XX XX : mov eax, XX XX XX XX
     case 0xB9:  // b9 XX XX XX XX : mov ecx, XX XX XX XX
-    case 0xA1:  // A1 XX XX XX XX : mov eax, dword ptr ds:[XXXXXXXX]
       return 5;
 
     // Cannot overwrite control-instruction. Return 0 to indicate failure.
@@ -452,7 +468,18 @@ static size_t GetInstructionSize(uptr address) {
       return 0;
   }
 
+  switch (0x00FFFFFF & *(u32*)address) {
+    case 0x24A48D:  // 8D A4 24 XX XX XX XX : lea esp, [esp + XX XX XX XX]
+      return 7;
+  }
+
 #if SANITIZER_WINDOWS64
+  switch (*(u8*)address) {
+    case 0xA1:  // A1 XX XX XX XX XX XX XX XX :
+                //   movabs eax, dword ptr ds:[XXXXXXXX]
+      return 8;
+  }
+
   switch (*(u16*)address) {
     case 0x5040:  // push rax
     case 0x5140:  // push rcx
@@ -477,17 +504,20 @@ static size_t GetInstructionSize(uptr address) {
     case 0xd9f748:    // 48 f7 d9 : neg rcx
     case 0xd12b48:    // 48 2b d1 : sub rdx, rcx
     case 0x07c1f6:    // f6 c1 07 : test cl, 0x7
+    case 0xc98548:    // 48 85 C9 : test rcx, rcx
     case 0xc0854d:    // 4d 85 c0 : test r8, r8
     case 0xc2b60f:    // 0f b6 c2 : movzx eax, dl
     case 0xc03345:    // 45 33 c0 : xor r8d, r8d
+    case 0xdb3345:    // 45 33 DB : xor r11d, r11d
     case 0xd98b4c:    // 4c 8b d9 : mov r11, rcx
     case 0xd28b4c:    // 4c 8b d2 : mov r10, rdx
+    case 0xc98b4c:    // 4C 8B C9 : mov r9, rcx
     case 0xd2b60f:    // 0f b6 d2 : movzx edx, dl
     case 0xca2b48:    // 48 2b ca : sub rcx, rdx
     case 0x10b70f:    // 0f b7 10 : movzx edx, WORD PTR [rax]
     case 0xc00b4d:    // 3d 0b c0 : or r8, r8
     case 0xd18b48:    // 48 8b d1 : mov rdx, rcx
-    case 0xdc8b4c:    // 4c 8b dc : mov r11,rsp
+    case 0xdc8b4c:    // 4c 8b dc : mov r11, rsp
     case 0xd18b4c:    // 4c 8b d1 : mov r10, rcx
       return 3;
 
@@ -496,11 +526,22 @@ static size_t GetInstructionSize(uptr address) {
     case 0x588948:    // 48 89 58 XX : mov QWORD PTR[rax + XX], rbx
       return 4;
 
+    case 0xec8148:    // 48 81 EC XX XX XX XX : sub rsp, XXXXXXXX
+      return 7;
+
     case 0x058b48:    // 48 8b 05 XX XX XX XX :
                       //   mov rax, QWORD PTR [rip + XXXXXXXX]
     case 0x25ff48:    // 48 ff 25 XX XX XX XX :
                       //   rex.W jmp QWORD PTR [rip + XXXXXXXX]
+
+      // Instructions having offset relative to 'rip' need offset adjustment.
+      if (rel_offset)
+        *rel_offset = 3;
       return 7;
+
+    case 0x2444c7:    // C7 44 24 XX YY YY YY YY
+                      //   mov dword ptr [rsp + XX], YYYYYYYY
+      return 8;
   }
 
   switch (*(u32*)(address)) {
@@ -513,6 +554,10 @@ static size_t GetInstructionSize(uptr address) {
 
 #else
 
+  switch (*(u8*)address) {
+    case 0xA1:  // A1 XX XX XX XX :  mov eax, dword ptr ds:[XXXXXXXX]
+      return 5;
+  }
   switch (*(u16*)address) {
     case 0x458B:  // 8B 45 XX : mov eax, dword ptr [ebp + XX]
     case 0x5D8B:  // 8B 5D XX : mov ebx, dword ptr [ebp + XX]
@@ -566,6 +611,28 @@ static size_t RoundUpToInstrBoundary(size_t size, uptr address) {
   return cursor;
 }
 
+static bool CopyInstructions(uptr to, uptr from, size_t size) {
+  size_t cursor = 0;
+  while (cursor != size) {
+    size_t rel_offset = 0;
+    size_t instruction_size = GetInstructionSize(from + cursor, &rel_offset);
+    _memcpy((void*)(to + cursor), (void*)(from + cursor),
+            (size_t)instruction_size);
+    if (rel_offset) {
+      uptr delta = to - from;
+      uptr relocated_offset = *(u32*)(to + cursor + rel_offset) - delta;
+#if SANITIZER_WINDOWS64
+      if (relocated_offset + 0x80000000U >= 0xFFFFFFFFU)
+        return false;
+#endif
+      *(u32*)(to + cursor + rel_offset) = relocated_offset;
+    }
+    cursor += instruction_size;
+  }
+  return true;
+}
+
+
 #if !SANITIZER_WINDOWS64
 bool OverrideFunctionWithDetour(
     uptr old_func, uptr new_func, uptr *orig_old_func) {
@@ -656,7 +723,8 @@ bool OverrideFunctionWithHotPatch(
     uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
     if (!trampoline)
       return false;
-    CopyInstructions(trampoline, old_func, instruction_size);
+    if (!CopyInstructions(trampoline, old_func, instruction_size))
+      return false;
     WriteDirectBranch(trampoline + instruction_size,
                       old_func + instruction_size);
     *orig_old_func = trampoline;
@@ -705,7 +773,8 @@ bool OverrideFunctionWithTrampoline(
     uptr trampoline = AllocateMemoryForTrampoline(old_func, trampoline_length);
     if (!trampoline)
       return false;
-    CopyInstructions(trampoline, old_func, instructions_length);
+    if (!CopyInstructions(trampoline, old_func, instructions_length))
+      return false;
     WriteDirectBranch(trampoline + instructions_length,
                       old_func + instructions_length);
     *orig_old_func = trampoline;
@@ -820,6 +889,32 @@ uptr InternalGetProcAddress(void *module, const char *func_name) {
     if (!strcmp(func_name, name)) {
       DWORD index = ordinals[i];
       RVAPtr<char> func(module, functions[index]);
+
+      // Handle forwarded functions.
+      DWORD offset = functions[index];
+      if (offset >= export_directory->VirtualAddress &&
+          offset < export_directory->VirtualAddress + export_directory->Size) {
+        // An entry for a forwarded function is a string with the following
+        // format: "<module> . <function_name>" that is stored into the
+        // exported directory.
+        char function_name[256];
+        size_t funtion_name_length = _strlen(func);
+        if (funtion_name_length >= sizeof(function_name) - 1)
+          InterceptionFailed();
+
+        _memcpy(function_name, func, funtion_name_length);
+        function_name[funtion_name_length] = '\0';
+        char* separator = _strchr(function_name, '.');
+        if (!separator)
+          InterceptionFailed();
+        *separator = '\0';
+
+        void* redirected_module = GetModuleHandleA(function_name);
+        if (!redirected_module)
+          InterceptionFailed();
+        return InternalGetProcAddress(redirected_module, separator + 1);
+      }
+
       return (uptr)(char *)func;
     }
   }
@@ -827,19 +922,18 @@ uptr InternalGetProcAddress(void *module, const char *func_name) {
   return 0;
 }
 
-static bool GetFunctionAddressInDLLs(const char *func_name, uptr *func_addr) {
-  *func_addr = 0;
+bool OverrideFunction(
+    const char *func_name, uptr new_func, uptr *orig_old_func) {
+  bool hooked = false;
   void **DLLs = InterestingDLLsAvailable();
-  for (size_t i = 0; *func_addr == 0 && DLLs[i]; ++i)
-    *func_addr = InternalGetProcAddress(DLLs[i], func_name);
-  return (*func_addr != 0);
-}
-
-bool OverrideFunction(const char *name, uptr new_func, uptr *orig_old_func) {
-  uptr orig_func;
-  if (!GetFunctionAddressInDLLs(name, &orig_func))
-    return false;
-  return OverrideFunction(orig_func, new_func, orig_old_func);
+  for (size_t i = 0; DLLs[i]; ++i) {
+    uptr func_addr = InternalGetProcAddress(DLLs[i], func_name);
+    if (func_addr &&
+        OverrideFunction(func_addr, new_func, orig_old_func)) {
+      hooked = true;
+    }
+  }
+  return hooked;
 }
 
 bool OverrideImportedFunction(const char *module_to_patch,