[PGO] Enable building compiler-rt profile support library on Windows

[slingn]

Summary

This change configures Windows builds to build the complier-rt profile support library (clang_rt.profile-i386.lib). Windows API incompatibilities in the compiler-rt profile lib are also fixed.

[slingn]

Updated commit message.

[davidxl]

lib/profile/mmap-windows.c

2 ↗

(On Diff #43809)

This file needs to be re-licensed and redistributed under LLVM* license. need to talk to the contributor of the file and get the permission.

124 ↗

(On Diff #43809)

better use C style comments -- also in many other places.

[slingn]

lib/profile/mmap-windows.c

2 ↗

(On Diff #43809)

I thought public domain means that there are no restrictions whatsoever - including re-licensing, selling, etc. No need for attribution even.

I modeled this after the MD5 attribution:
llvm/include/llvm/Support/MD5.h

[slingn]

Fix C++ -> C style comments in mmap-windows.c compatibility file.

[davidxl]

Is there a missing change in CMakeLists.txt for the new file added?

[slingn]

mmap-windows.c gets #included directly in GCDAProfiling.c since the compatibility mmap()/msync()/flock() functions are not used anywhere else (they are static).

I agree it is a bit odd - and CMake won't properly detect changes to mmap-windows.c the way things are now. Perhaps it would be better to mark them with COMPILER_RT_VISIBILITY (and not static).

[slingn]

Updated for davidxl's comments

-refactor Windows mmap compatibility code to have a header file, not include implementation with static functions directly
-switch to C-style comments in Windows mmap compatibility code

[slingn]

Fix header comment.

[davidxl]

lib/profile/CMakeLists.txt

40

This is not needed if the source file is properly guarded -- see other platform specific files.

lib/profile/WindowsMMap.c

22

Move this line above the first include.

[slingn]

-Fixed guard of WindowsMMap.c

[davidxl]

lgtm

cmake/config-ix.cmake

 if (COMPILER_RT_HAS_SANITIZER_COMMON AND MSAN_SUPPORTED_ARCH AND
     OS_NAME MATCHES "Linux")
   set(COMPILER_RT_HAS_MSAN TRUE)
 else()
   set(COMPILER_RT_HAS_MSAN FALSE)
 endif()
 
 if (PROFILE_SUPPORTED_ARCH AND
-    OS_NAME MATCHES "Darwin|Linux|FreeBSD")
+    OS_NAME MATCHES "Darwin|Linux|FreeBSD|Windows")
   set(COMPILER_RT_HAS_PROFILE TRUE)
 else()
   set(COMPILER_RT_HAS_PROFILE FALSE)
 endif()
 
 if (COMPILER_RT_HAS_SANITIZER_COMMON AND TSAN_SUPPORTED_ARCH AND
     OS_NAME MATCHES "Darwin|Linux|FreeBSD")
   set(COMPILER_RT_HAS_TSAN TRUE)

lib/profile/CMakeLists.txt

set(PROFILE_SOURCES
   InstrProfilingFile.c
   InstrProfilingWriter.c
   InstrProfilingPlatformDarwin.c
   InstrProfilingPlatformLinux.c
   InstrProfilingPlatformOther.c
   InstrProfilingRuntime.cc
   InstrProfilingUtil.c)
 
+if(MSVC)
+    list(APPEND PROFILE_SOURCES WindowsMMap.c)
+endif()
+
 if(UNIX)
  set(EXTRA_FLAGS
      -fPIC
      -Wno-pedantic)
 else()
  set(EXTRA_FLAGS
      -fPIC)
 endif()

lib/profile/GCDAProfiling.c

 
 #include "InstrProfilingUtil.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+
+#if defined(_WIN32)
+#include "WindowsMMap.h"
+#else
 #include <sys/mman.h>
 #include <sys/file.h>
+#endif
 
 #define I386_FREEBSD (defined(__FreeBSD__) && defined(__i386__))
 
 #if !defined(_MSC_VER) && !I386_FREEBSD
 #include <stdint.h>
 #endif
 
 #if defined(_MSC_VER)
+typedef unsigned char uint8_t;
 typedef unsigned int uint32_t;
 typedef unsigned long long uint64_t;
 #elif I386_FREEBSD
 /* System headers define 'size_t' incorrectly on x64 FreeBSD (prior to
  * FreeBSD 10, r232261) when compiled in 32-bit mode.
  */
 typedef unsigned char uint8_t;
 typedef unsigned int uint32_t;

lib/profile/InstrProfilingFile.c

 #include "InstrProfilingUtil.h"
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #define UNCONST(ptr) ((void *)(uintptr_t)(ptr))
 
+#ifdef _MSC_VER
+#define snprintf _snprintf
+#endif
+
 /* Return 1 if there is an error, otherwise return  0.  */
 static uint32_t fileWriter(ProfDataIOVec *IOVecs, uint32_t NumIOVecs,
                            void **WriterCtx) {
   uint32_t I;
   FILE *File = (FILE *)*WriterCtx;
   for (I = 0; I < NumIOVecs; I++) {
     if (fwrite(IOVecs[I].Data, IOVecs[I].ElmSize, IOVecs[I].NumElm, File) !=
         IOVecs[I].NumElm)

lib/profile/WindowsMMap.h

+/*===- mmap-windows.h - Support library for PGO instrumentation -----------===*\
+|*
+|*                     The LLVM Compiler Infrastructure
+|*
+|* This file is distributed under the University of Illinois Open Source
+|* License. See LICENSE.TXT for details.
+|*
+\*===----------------------------------------------------------------------===*/
+
+#ifndef PROFILE_INSTRPROFILING_WINDOWS_MMAP_H
+#define PROFILE_INSTRPROFILING_WINDOWS_MMAP_H
+
+#if defined(_WIN32)
+
+#include <BaseTsd.h>
+#include <io.h>
+#include <sys/types.h>
+
+/*
+ * mmap() flags
+ */
+#define PROT_READ     0x1
+#define PROT_WRITE    0x2
+/* This flag is only available in WinXP+ */
+#ifdef FILE_MAP_EXECUTE
+#define PROT_EXEC     0x4
+#else
+#define PROT_EXEC        0x0
+#define FILE_MAP_EXECUTE 0
+#endif
+
+#define MAP_FILE      0x00
+#define MAP_SHARED    0x01
+#define MAP_PRIVATE   0x02
+#define MAP_ANONYMOUS 0x20
+#define MAP_ANON      MAP_ANONYMOUS
+#define MAP_FAILED    ((void *) -1)
+
+/*
+ * msync() flags
+ */
+#define MS_ASYNC        0x0001  /* return immediately */
+#define MS_INVALIDATE   0x0002  /* invalidate all cached data */
+#define MS_SYNC         0x0010  /* msync synchronously */
+
+/*
+ * flock() operations
+ */
+#define   LOCK_SH   1    /* shared lock */
+#define   LOCK_EX   2    /* exclusive lock */
+#define   LOCK_NB   4    /* don't block when locking */
+#define   LOCK_UN   8    /* unlock */
+
+void *mmap(void *start, size_t length, int prot, int flags, int fd,
+           off_t offset);
+
+void munmap(void *addr, size_t length);
+
+int msync(void *addr, size_t length, int flags);
+
+int flock(int fd, int operation);
+
+#endif /* _WIN32 */
+
+#endif /* PROFILE_INSTRPROFILING_WINDOWS_MMAP_H */

lib/profile/WindowsMMap.c

+/*
+ * This code is derived from uClibc (original license follows).
+ * https://git.uclibc.org/uClibc/tree/utils/mmap-windows.c
+ */
+ /* mmap() replacement for Windows
+ *
+ * Author: Mike Frysinger <[e-mail]>
+ * Placed into the public domain
+ */
+
+/* References:
+ * CreateFileMapping: http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx
+ * CloseHandle:       http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx
+ * MapViewOfFile:     http://msdn.microsoft.com/en-us/library/aa366761(VS.85).aspx
+ * UnmapViewOfFile:   http://msdn.microsoft.com/en-us/library/aa366882(VS.85).aspx
+ */
+
+#include "WindowsMMap.h"
+#include "InstrProfiling.h"
+
+#if defined(_WIN32)
+
+#ifdef __USE_FILE_OFFSET64
+# define DWORD_HI(x) (x >> 32)
+# define DWORD_LO(x) ((x) & 0xffffffff)
+#else
+# define DWORD_HI(x) (0)
+# define DWORD_LO(x) (x)
+#endif
+
+COMPILER_RT_VISIBILITY
+void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
+{
+  if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
+    return MAP_FAILED;
+  if (fd == -1) {
+    if (!(flags & MAP_ANON) || offset)
+      return MAP_FAILED;
+  } else if (flags & MAP_ANON)
+    return MAP_FAILED;
+
+  DWORD flProtect;
+  if (prot & PROT_WRITE) {
+    if (prot & PROT_EXEC)
+      flProtect = PAGE_EXECUTE_READWRITE;
+    else
+      flProtect = PAGE_READWRITE;
+  } else if (prot & PROT_EXEC) {
+    if (prot & PROT_READ)
+      flProtect = PAGE_EXECUTE_READ;
+    else if (prot & PROT_EXEC)
+      flProtect = PAGE_EXECUTE;
+  } else
+    flProtect = PAGE_READONLY;
+
+  off_t end = length + offset;
+  HANDLE mmap_fd, h;
+  if (fd == -1)
+    mmap_fd = INVALID_HANDLE_VALUE;
+  else
+    mmap_fd = (HANDLE)_get_osfhandle(fd);
+  h = CreateFileMapping(mmap_fd, NULL, flProtect, DWORD_HI(end), DWORD_LO(end), NULL);
+  if (h == NULL)
+    return MAP_FAILED;
+
+  DWORD dwDesiredAccess;
+  if (prot & PROT_WRITE)
+    dwDesiredAccess = FILE_MAP_WRITE;
+  else
+    dwDesiredAccess = FILE_MAP_READ;
+  if (prot & PROT_EXEC)
+    dwDesiredAccess |= FILE_MAP_EXECUTE;
+  if (flags & MAP_PRIVATE)
+    dwDesiredAccess |= FILE_MAP_COPY;
+  void *ret = MapViewOfFile(h, dwDesiredAccess, DWORD_HI(offset), DWORD_LO(offset), length);
+  if (ret == NULL) {
+    CloseHandle(h);
+    ret = MAP_FAILED;
+  }
+  return ret;
+}
+
+COMPILER_RT_VISIBILITY
+void munmap(void *addr, size_t length)
+{
+  UnmapViewOfFile(addr);
+  /* ruh-ro, we leaked handle from CreateFileMapping() ... */
+}
+
+COMPILER_RT_VISIBILITY
+int msync(void *addr, size_t length, int flags)
+{
+  if (flags & MS_INVALIDATE)
+    return -1; /* Not supported. */
+
+  /* Exactly one of MS_ASYNC or MS_SYNC must be specified. */
+  switch (flags & (MS_ASYNC | MS_SYNC)) {
+    case MS_SYNC:
+    case MS_ASYNC:
+      break;
+    default:
+      return -1;
+  }
+
+  if (!FlushViewOfFile(addr, length))
+    return -1;
+
+  if (flags & MS_SYNC) {
+    /* FIXME: No longer have access to handle from CreateFileMapping(). */
+    /*
+     * if (!FlushFileBuffers(h))
+     *   return -1;
+     */
+  }
+
+  return 0;
+}
+
+COMPILER_RT_VISIBILITY
+int flock(int fd, int operation)
+{
+  return -1; /* Not supported. */
+}
+
+#undef DWORD_HI
+#undef DWORD_LO
+
+#endif /* _WIN32 */