folly/tracing/StaticTracepoint-ELFx86.h

   1 /*
   2  * Copyright 2017 Facebook, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *   http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #pragma once
  18
  19 // clang-format off
  20
  21 // Default constraint for the probe arguments as operands.
  22 #ifndef FOLLY_SDT_ARG_CONSTRAINT
  23 #define FOLLY_SDT_ARG_CONSTRAINT      "nor"
  24 #endif
  25
  26 // Instruction to emit for the probe.
  27 #define FOLLY_SDT_NOP                 nop
  28
  29 // Note section properties.
  30 #define FOLLY_SDT_NOTE_NAME           "stapsdt"
  31 #define FOLLY_SDT_NOTE_TYPE           3
  32
  33 // Size of address depending on platform.
  34 #ifdef __LP64__
  35 #define FOLLY_SDT_ASM_ADDR            .8byte
  36 #else
  37 #define FOLLY_SDT_ASM_ADDR            .4byte
  38 #endif
  39
  40 // Assembler helper Macros.
  41 #define FOLLY_SDT_S(x)                #x
  42 #define FOLLY_SDT_ASM_1(x)            FOLLY_SDT_S(x) "\n"
  43 #define FOLLY_SDT_ASM_2(a, b)         FOLLY_SDT_S(a) "," FOLLY_SDT_S(b) "\n"
  44 #define FOLLY_SDT_ASM_3(a, b, c)      FOLLY_SDT_S(a) "," FOLLY_SDT_S(b) ","    \
  45                                       FOLLY_SDT_S(c) "\n"
  46 #define FOLLY_SDT_ASM_STRING(x)       FOLLY_SDT_ASM_1(.asciz FOLLY_SDT_S(x))
  47
  48 // Helper to determine the size of an argument.
  49 #define FOLLY_SDT_ISARRAY(x)  (__builtin_classify_type(x) == 14)
  50 #define FOLLY_SDT_ARGSIZE(x)  (FOLLY_SDT_ISARRAY(x) ? sizeof(void*) : sizeof(x))
  51
  52 // Format of each probe arguments as operand.
  53 // Size of the arugment tagged with FOLLY_SDT_Sn, with "n" constraint.
  54 // Value of the argument tagged with FOLLY_SDT_An, with configured constraint.
  55 #define FOLLY_SDT_ARG(n, x)                                                    \
  56   [FOLLY_SDT_S##n] "n"                ((size_t)FOLLY_SDT_ARGSIZE(x)),          \
  57   [FOLLY_SDT_A##n] FOLLY_SDT_ARG_CONSTRAINT (x)
  58
  59 // Templates to append arguments as operands.
  60 #define FOLLY_SDT_OPERANDS_0()        [__sdt_dummy] "g" (0)
  61 #define FOLLY_SDT_OPERANDS_1(_1)      FOLLY_SDT_ARG(1, _1)
  62 #define FOLLY_SDT_OPERANDS_2(_1, _2)                                           \
  63   FOLLY_SDT_OPERANDS_1(_1), FOLLY_SDT_ARG(2, _2)
  64 #define FOLLY_SDT_OPERANDS_3(_1, _2, _3)                                       \
  65   FOLLY_SDT_OPERANDS_2(_1, _2), FOLLY_SDT_ARG(3, _3)
  66 #define FOLLY_SDT_OPERANDS_4(_1, _2, _3, _4)                                   \
  67   FOLLY_SDT_OPERANDS_3(_1, _2, _3), FOLLY_SDT_ARG(4, _4)
  68 #define FOLLY_SDT_OPERANDS_5(_1, _2, _3, _4, _5)                               \
  69   FOLLY_SDT_OPERANDS_4(_1, _2, _3, _4), FOLLY_SDT_ARG(5, _5)
  70 #define FOLLY_SDT_OPERANDS_6(_1, _2, _3, _4, _5, _6)                           \
  71   FOLLY_SDT_OPERANDS_5(_1, _2, _3, _4, _5), FOLLY_SDT_ARG(6, _6)
  72 #define FOLLY_SDT_OPERANDS_7(_1, _2, _3, _4, _5, _6, _7)                       \
  73   FOLLY_SDT_OPERANDS_6(_1, _2, _3, _4, _5, _6), FOLLY_SDT_ARG(7, _7)
  74 #define FOLLY_SDT_OPERANDS_8(_1, _2, _3, _4, _5, _6, _7, _8)                   \
  75   FOLLY_SDT_OPERANDS_7(_1, _2, _3, _4, _5, _6, _7), FOLLY_SDT_ARG(8, _8)
  76
  77 // Templates to reference the arguments from operands in note section.
  78 #define FOLLY_SDT_ARGFMT(no)        %n[FOLLY_SDT_S##no]@%[FOLLY_SDT_A##no]
  79 #define FOLLY_SDT_ARG_TEMPLATE_0    /*No arguments*/
  80 #define FOLLY_SDT_ARG_TEMPLATE_1    FOLLY_SDT_ARGFMT(1)
  81 #define FOLLY_SDT_ARG_TEMPLATE_2    FOLLY_SDT_ARG_TEMPLATE_1 FOLLY_SDT_ARGFMT(2)
  82 #define FOLLY_SDT_ARG_TEMPLATE_3    FOLLY_SDT_ARG_TEMPLATE_2 FOLLY_SDT_ARGFMT(3)
  83 #define FOLLY_SDT_ARG_TEMPLATE_4    FOLLY_SDT_ARG_TEMPLATE_3 FOLLY_SDT_ARGFMT(4)
  84 #define FOLLY_SDT_ARG_TEMPLATE_5    FOLLY_SDT_ARG_TEMPLATE_4 FOLLY_SDT_ARGFMT(5)
  85 #define FOLLY_SDT_ARG_TEMPLATE_6    FOLLY_SDT_ARG_TEMPLATE_5 FOLLY_SDT_ARGFMT(6)
  86 #define FOLLY_SDT_ARG_TEMPLATE_7    FOLLY_SDT_ARG_TEMPLATE_6 FOLLY_SDT_ARGFMT(7)
  87 #define FOLLY_SDT_ARG_TEMPLATE_8    FOLLY_SDT_ARG_TEMPLATE_7 FOLLY_SDT_ARGFMT(8)
  88
  89 // Structure of note section for the probe.
  90 #define FOLLY_SDT_NOTE_CONTENT(provider, name, arg_template)                   \
  91   FOLLY_SDT_ASM_1(990: FOLLY_SDT_NOP)                                          \
  92   FOLLY_SDT_ASM_3(     .pushsection .note.stapsdt,"","note")                   \
  93   FOLLY_SDT_ASM_1(     .balign 4)                                              \
  94   FOLLY_SDT_ASM_3(     .4byte 992f-991f, 994f-993f, FOLLY_SDT_NOTE_TYPE)       \
  95   FOLLY_SDT_ASM_1(991: .asciz FOLLY_SDT_NOTE_NAME)                             \
  96   FOLLY_SDT_ASM_1(992: .balign 4)                                              \
  97   FOLLY_SDT_ASM_1(993: FOLLY_SDT_ASM_ADDR 990b)                                \
  98   FOLLY_SDT_ASM_1(     FOLLY_SDT_ASM_ADDR 0) /*Reserved for Semaphore address*/\
  99   FOLLY_SDT_ASM_1(     FOLLY_SDT_ASM_ADDR 0) /*Reserved for Semaphore name*/   \
 100   FOLLY_SDT_ASM_STRING(provider)                                               \
 101   FOLLY_SDT_ASM_STRING(name)                                                   \
 102   FOLLY_SDT_ASM_STRING(arg_template)                                           \
 103   FOLLY_SDT_ASM_1(994: .balign 4)                                              \
 104   FOLLY_SDT_ASM_1(     .popsection)
 105
 106 // Main probe Macro.
 107 #define FOLLY_SDT_PROBE(provider, name, n, arglist)                            \
 108     __asm__ __volatile__ (                                                     \
 109       FOLLY_SDT_NOTE_CONTENT(provider, name, FOLLY_SDT_ARG_TEMPLATE_##n)       \
 110       :: FOLLY_SDT_OPERANDS_##n arglist                                        \
 111     )                                                                          \
 112
 113 // Helper Macros to handle variadic arguments.
 114 #define FOLLY_SDT_NARG_(_0, _1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
 115 #define FOLLY_SDT_NARG(...)                                                    \
 116   FOLLY_SDT_NARG_(__VA_ARGS__, 8, 7, 6, 5, 4, 3, 2, 1, 0)
 117 #define FOLLY_SDT_PROBE_N(provider, name, N, ...)                              \
 118   FOLLY_SDT_PROBE(provider, name, N, (__VA_ARGS__))