2 * Copyright 2016-present Facebook, Inc.
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
21 // Default constraint for the probe arguments as operands.
22 #ifndef FOLLY_SDT_ARG_CONSTRAINT
23 #define FOLLY_SDT_ARG_CONSTRAINT "nor"
26 // Instruction to emit for the probe.
27 #define FOLLY_SDT_NOP nop
29 // Note section properties.
30 #define FOLLY_SDT_NOTE_NAME "stapsdt"
31 #define FOLLY_SDT_NOTE_TYPE 3
33 // Size of address depending on platform.
35 #define FOLLY_SDT_ASM_ADDR .8byte
37 #define FOLLY_SDT_ASM_ADDR .4byte
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) "," \
46 #define FOLLY_SDT_ASM_STRING(x) FOLLY_SDT_ASM_1(.asciz FOLLY_SDT_S(x))
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))
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)
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)
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)
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)
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 \
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__))