2 * Copyright 2017 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.
19 // Default constraint for the probe arguments as operands.
20 #ifndef FOLLY_SDT_ARG_CONSTRAINT
21 #define FOLLY_SDT_ARG_CONSTRAINT "nor"
24 // Instruction to emit for the probe.
25 #define FOLLY_SDT_NOP nop
27 // Note section properties.
28 #define FOLLY_SDT_NOTE_NAME "stapsdt"
29 #define FOLLY_SDT_NOTE_TYPE 3
31 // Size of address depending on platform.
33 #define FOLLY_SDT_ASM_ADDR .8byte
35 #define FOLLY_SDT_ASM_ADDR .4byte
38 // Assembler helper Macros.
39 #define FOLLY_SDT_S(x) #x
40 #define FOLLY_SDT_ASM_1(x) FOLLY_SDT_S(x) "\n"
41 #define FOLLY_SDT_ASM_2(a, b) FOLLY_SDT_S(a) "," FOLLY_SDT_S(b) "\n"
42 #define FOLLY_SDT_ASM_3(a, b, c) FOLLY_SDT_S(a) "," FOLLY_SDT_S(b) "," \
44 #define FOLLY_SDT_ASM_STRING(x) FOLLY_SDT_ASM_1(.asciz FOLLY_SDT_S(x))
46 // Helper to determine the size of an argument.
47 #define FOLLY_SDT_ISARRAY(x) (__builtin_classify_type(x) == 14)
48 #define FOLLY_SDT_ARGSIZE(x) (FOLLY_SDT_ISARRAY(x) ? sizeof(void*) : sizeof(x))
50 // Format of each probe arguments as operand.
51 // Size of the arugment tagged with FOLLY_SDT_Sn, with "n" constraint.
52 // Value of the argument tagged with FOLLY_SDT_An, with configured constraint.
53 #define FOLLY_SDT_ARG(n, x) \
54 [FOLLY_SDT_S##n] "n" ((size_t)FOLLY_SDT_ARGSIZE(x)), \
55 [FOLLY_SDT_A##n] FOLLY_SDT_ARG_CONSTRAINT (x)
57 // Templates to append arguments as operands.
58 #define FOLLY_SDT_OPERANDS_0() [__sdt_dummy] "g" (0)
59 #define FOLLY_SDT_OPERANDS_1(_1) FOLLY_SDT_ARG(1, _1)
60 #define FOLLY_SDT_OPERANDS_2(_1, _2) \
61 FOLLY_SDT_OPERANDS_1(_1), FOLLY_SDT_ARG(2, _2)
62 #define FOLLY_SDT_OPERANDS_3(_1, _2, _3) \
63 FOLLY_SDT_OPERANDS_2(_1, _2), FOLLY_SDT_ARG(3, _3)
64 #define FOLLY_SDT_OPERANDS_4(_1, _2, _3, _4) \
65 FOLLY_SDT_OPERANDS_3(_1, _2, _3), FOLLY_SDT_ARG(4, _4)
66 #define FOLLY_SDT_OPERANDS_5(_1, _2, _3, _4, _5) \
67 FOLLY_SDT_OPERANDS_4(_1, _2, _3, _4), FOLLY_SDT_ARG(5, _5)
68 #define FOLLY_SDT_OPERANDS_6(_1, _2, _3, _4, _5, _6) \
69 FOLLY_SDT_OPERANDS_5(_1, _2, _3, _4, _5), FOLLY_SDT_ARG(6, _6)
70 #define FOLLY_SDT_OPERANDS_7(_1, _2, _3, _4, _5, _6, _7) \
71 FOLLY_SDT_OPERANDS_6(_1, _2, _3, _4, _5, _6), FOLLY_SDT_ARG(7, _7)
72 #define FOLLY_SDT_OPERANDS_8(_1, _2, _3, _4, _5, _6, _7, _8) \
73 FOLLY_SDT_OPERANDS_7(_1, _2, _3, _4, _5, _6, _7), FOLLY_SDT_ARG(8, _8)
75 // Templates to reference the arguments from operands in note section.
76 #define FOLLY_SDT_ARGFMT(no) %n[FOLLY_SDT_S##no]@%[FOLLY_SDT_A##no]
77 #define FOLLY_SDT_ARG_TEMPLATE_0 /*No arguments*/
78 #define FOLLY_SDT_ARG_TEMPLATE_1 FOLLY_SDT_ARGFMT(1)
79 #define FOLLY_SDT_ARG_TEMPLATE_2 FOLLY_SDT_ARG_TEMPLATE_1 FOLLY_SDT_ARGFMT(2)
80 #define FOLLY_SDT_ARG_TEMPLATE_3 FOLLY_SDT_ARG_TEMPLATE_2 FOLLY_SDT_ARGFMT(3)
81 #define FOLLY_SDT_ARG_TEMPLATE_4 FOLLY_SDT_ARG_TEMPLATE_3 FOLLY_SDT_ARGFMT(4)
82 #define FOLLY_SDT_ARG_TEMPLATE_5 FOLLY_SDT_ARG_TEMPLATE_4 FOLLY_SDT_ARGFMT(5)
83 #define FOLLY_SDT_ARG_TEMPLATE_6 FOLLY_SDT_ARG_TEMPLATE_5 FOLLY_SDT_ARGFMT(6)
84 #define FOLLY_SDT_ARG_TEMPLATE_7 FOLLY_SDT_ARG_TEMPLATE_6 FOLLY_SDT_ARGFMT(7)
85 #define FOLLY_SDT_ARG_TEMPLATE_8 FOLLY_SDT_ARG_TEMPLATE_7 FOLLY_SDT_ARGFMT(8)
87 // Structure of note section for the probe.
88 #define FOLLY_SDT_NOTE_CONTENT(provider, name, arg_template) \
89 FOLLY_SDT_ASM_1(990: FOLLY_SDT_NOP) \
90 FOLLY_SDT_ASM_3( .pushsection .note.stapsdt,"","note") \
91 FOLLY_SDT_ASM_1( .balign 4) \
92 FOLLY_SDT_ASM_3( .4byte 992f-991f, 994f-993f, FOLLY_SDT_NOTE_TYPE) \
93 FOLLY_SDT_ASM_1(991: .asciz FOLLY_SDT_NOTE_NAME) \
94 FOLLY_SDT_ASM_1(992: .balign 4) \
95 FOLLY_SDT_ASM_1(993: FOLLY_SDT_ASM_ADDR 990b) \
96 FOLLY_SDT_ASM_1( FOLLY_SDT_ASM_ADDR 0) /*Reserved for Semaphore address*/\
97 FOLLY_SDT_ASM_1( FOLLY_SDT_ASM_ADDR 0) /*Reserved for Semaphore name*/ \
98 FOLLY_SDT_ASM_STRING(provider) \
99 FOLLY_SDT_ASM_STRING(name) \
100 FOLLY_SDT_ASM_STRING(arg_template) \
101 FOLLY_SDT_ASM_1(994: .balign 4) \
102 FOLLY_SDT_ASM_1( .popsection)
105 #define FOLLY_SDT_PROBE(provider, name, n, arglist) \
106 __asm__ __volatile__ ( \
107 FOLLY_SDT_NOTE_CONTENT(provider, name, FOLLY_SDT_ARG_TEMPLATE_##n) \
108 :: FOLLY_SDT_OPERANDS_##n arglist \
111 // Helper Macros to handle variadic arguments.
112 #define FOLLY_SDT_NARG_(_0, _1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
113 #define FOLLY_SDT_NARG(...) \
114 FOLLY_SDT_NARG_(__VA_ARGS__, 8, 7, 6, 5, 4, 3, 2, 1, 0)
115 #define FOLLY_SDT_PROBE_N(provider, name, N, ...) \
116 FOLLY_SDT_PROBE(provider, name, N, (__VA_ARGS__))