compiler-rt/lib/profile/InstrProfilingPlatformWindows.c

   1 /*===- InstrProfilingPlatformWindows.c - Profile data on Windows ----------===*\
   2 |*
   3 |* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 |* See https://llvm.org/LICENSE.txt for license information.
   5 |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 |*
   7 \*===----------------------------------------------------------------------===*/
   8
   9 #include <stddef.h>
  10
  11 #include "InstrProfiling.h"
  12 #include "InstrProfilingInternal.h"
  13
  14 #if defined(_WIN32)
  15
  16 #if defined(_MSC_VER)
  17 /* Merge read-write sections into .data. */
  18 #pragma comment(linker, "/MERGE:.lprfb=.data")
  19 #pragma comment(linker, "/MERGE:.lprfd=.data")
  20 #pragma comment(linker, "/MERGE:.lprfv=.data")
  21 #pragma comment(linker, "/MERGE:.lprfnd=.data")
  22 /* Do *NOT* merge .lprfn and .lcovmap into .rdata. llvm-cov must be able to find
  23  * after the fact.
  24  * Do *NOT* merge .lprfc .rdata. When binary profile correlation is enabled,
  25  * llvm-cov must be able to find after the fact.
  26  */
  27
  28 /* Allocate read-only section bounds. */
  29 #pragma section(".lprfn$A", read)
  30 #pragma section(".lprfn$Z", read)
  31
  32 /* Allocate read-write section bounds. */
  33 #pragma section(".lprfd$A", read, write)
  34 #pragma section(".lprfd$Z", read, write)
  35 #pragma section(".lprfc$A", read, write)
  36 #pragma section(".lprfc$Z", read, write)
  37 #pragma section(".lprfb$A", read, write)
  38 #pragma section(".lprfb$Z", read, write)
  39 #pragma section(".lorderfile$A", read, write)
  40 #pragma section(".lprfnd$A", read, write)
  41 #pragma section(".lprfnd$Z", read, write)
  42 #endif
  43
  44 __llvm_profile_data COMPILER_RT_SECTION(".lprfd$A") DataStart = {0};
  45 __llvm_profile_data COMPILER_RT_SECTION(".lprfd$Z") DataEnd = {0};
  46
  47 const char COMPILER_RT_SECTION(".lprfn$A") NamesStart = '\0';
  48 const char COMPILER_RT_SECTION(".lprfn$Z") NamesEnd = '\0';
  49
  50 char COMPILER_RT_SECTION(".lprfc$A") CountersStart;
  51 char COMPILER_RT_SECTION(".lprfc$Z") CountersEnd;
  52 char COMPILER_RT_SECTION(".lprfb$A") BitmapStart;
  53 char COMPILER_RT_SECTION(".lprfb$Z") BitmapEnd;
  54 uint32_t COMPILER_RT_SECTION(".lorderfile$A") OrderFileStart;
  55
  56 ValueProfNode COMPILER_RT_SECTION(".lprfnd$A") VNodesStart;
  57 ValueProfNode COMPILER_RT_SECTION(".lprfnd$Z") VNodesEnd;
  58
  59 const __llvm_profile_data *__llvm_profile_begin_data(void) {
  60   return &DataStart + 1;
  61 }
  62 const __llvm_profile_data *__llvm_profile_end_data(void) { return &DataEnd; }
  63
  64 // Type profiling isn't implemented under MSVC ABI, so return NULL (rather than
  65 // implementing linker magic on Windows) to make it more explicit. To elaborate,
  66 // the current type profiling implementation maps a profiled vtable address to a
  67 // vtable variable through vtables mangled name. Under MSVC ABI, the variable
  68 // name for vtables might not be the mangled name (see
  69 // MicrosoftCXXABI::getAddrOfVTable in MicrosoftCXXABI.cpp for more details on
  70 // how a vtable name is computed). Note the mangled name is still in the vtable
  71 // IR (just not variable name) for mapping purpose, but more implementation work
  72 // is required.
  73 const VTableProfData *__llvm_profile_begin_vtables(void) { return NULL; }
  74 const VTableProfData *__llvm_profile_end_vtables(void) { return NULL; }
  75
  76 const char *__llvm_profile_begin_names(void) { return &NamesStart + 1; }
  77 const char *__llvm_profile_end_names(void) { return &NamesEnd; }
  78
  79 // Type profiling isn't supported on Windows, so return NULl to make it more
  80 // explicit.
  81 const char *__llvm_profile_begin_vtabnames(void) { return NULL; }
  82 const char *__llvm_profile_end_vtabnames(void) { return NULL; }
  83
  84 char *__llvm_profile_begin_counters(void) { return &CountersStart + 1; }
  85 char *__llvm_profile_end_counters(void) { return &CountersEnd; }
  86 char *__llvm_profile_begin_bitmap(void) { return &BitmapStart + 1; }
  87 char *__llvm_profile_end_bitmap(void) { return &BitmapEnd; }
  88 uint32_t *__llvm_profile_begin_orderfile(void) { return &OrderFileStart; }
  89
  90 ValueProfNode *__llvm_profile_begin_vnodes(void) { return &VNodesStart + 1; }
  91 ValueProfNode *__llvm_profile_end_vnodes(void) { return &VNodesEnd; }
  92
  93 ValueProfNode *CurrentVNode = &VNodesStart + 1;
  94 ValueProfNode *EndVNode = &VNodesEnd;
  95
  96 /* lld-link provides __buildid symbol which points to the 16 bytes build id when
  97  * using /build-id flag. https://lld.llvm.org/windows_support.html#lld-flags */
  98 #define BUILD_ID_LEN 16
  99 COMPILER_RT_WEAK uint8_t __buildid[BUILD_ID_LEN] = {0};
 100 COMPILER_RT_VISIBILITY int __llvm_write_binary_ids(ProfDataWriter *Writer) {
 101   static const uint8_t zeros[BUILD_ID_LEN] = {0};
 102   if (memcmp(__buildid, zeros, BUILD_ID_LEN) != 0) {
 103     if (Writer &&
 104         lprofWriteOneBinaryId(Writer, BUILD_ID_LEN, __buildid, 0) == -1)
 105       return -1;
 106     return sizeof(uint64_t) + BUILD_ID_LEN;
 107   }
 108   return 0;
 109 }
 110
 111 #endif