1#include "../builtins/assembly.h"
2
3    .syntax unified
4    .arch armv6t2
5    .fpu vfpv2
6    .code 32
7    .global _ZN6__xray19XRayPatchedFunctionE
8
9    @ Word-aligned function entry point
10    .p2align 2
11    @ Let C/C++ see the symbol
12    .global __xray_FunctionEntry
13    .hidden __xray_FunctionEntry
14    @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc)
15    @ Assume that "q" part of the floating-point registers is not used
16    @   for passing parameters to C/C++ functions.
17    .type __xray_FunctionEntry, %function
18    @ In C++ it is void extern "C" __xray_FunctionEntry(uint32_t FuncId) with
19    @   FuncId passed in r0 register.
20__xray_FunctionEntry:
21    PUSH {r1-r3,lr}
22    @ Save floating-point parameters of the instrumented function
23    VPUSH {d0-d7}
24    MOVW r1, #:lower16:_ZN6__xray19XRayPatchedFunctionE - (. + 16)
25    MOVT r1, #:upper16:_ZN6__xray19XRayPatchedFunctionE - (. + 12)
26    LDR r2, [pc, r1]
27    @ Handler address is nullptr if handler is not set
28    CMP r2, #0
29    BEQ FunctionEntry_restore
30    @ Function ID is already in r0 (the first parameter).
31    @ r1=0 means that we are tracing an entry event
32    MOV r1, #0
33    @ Call the handler with 2 parameters in r0 and r1
34    BLX r2
35FunctionEntry_restore:
36    @ Restore floating-point parameters of the instrumented function
37    VPOP {d0-d7}
38    POP {r1-r3,pc}
39
40    @ Word-aligned function entry point
41    .p2align 2
42    @ Let C/C++ see the symbol
43	.global __xray_FunctionExit
44	.hidden __xray_FunctionExit
45	@ Assume that d1-d7 are not used for the return value.
46    @ Assume that "q" part of the floating-point registers is not used for the
47    @   return value in C/C++.
48	.type __xray_FunctionExit, %function
49	@ In C++ it is extern "C" void __xray_FunctionExit(uint32_t FuncId) with
50    @   FuncId passed in r0 register.
51__xray_FunctionExit:
52    PUSH {r1-r3,lr}
53    @ Save the floating-point return value of the instrumented function
54    VPUSH {d0}
55    @ Load the handler address
56    MOVW r1, #:lower16:_ZN6__xray19XRayPatchedFunctionE - (. + 16)
57    MOVT r1, #:upper16:_ZN6__xray19XRayPatchedFunctionE - (. + 12)
58    LDR r2, [pc, r1]
59    @ Handler address is nullptr if handler is not set
60    CMP r2, #0
61    BEQ FunctionExit_restore
62    @ Function ID is already in r0 (the first parameter).
63    @ 1 means that we are tracing an exit event
64    MOV r1, #1
65    @ Call the handler with 2 parameters in r0 and r1
66    BLX r2
67FunctionExit_restore:
68    @ Restore the floating-point return value of the instrumented function
69    VPOP {d0}
70    POP {r1-r3,pc}
71
72    @ Word-aligned function entry point
73    .p2align 2
74    @ Let C/C++ see the symbol
75    .global __xray_FunctionTailExit
76    .hidden __xray_FunctionTailExit
77    @ It preserves all registers except r0, r12(ip), r14(lr) and r15(pc)
78    @ Assume that "q" part of the floating-point registers is not used
79    @   for passing parameters to C/C++ functions.
80    .type __xray_FunctionTailExit, %function
81    @ In C++ it is void extern "C" __xray_FunctionTailExit(uint32_t FuncId)
82    @   with FuncId passed in r0 register.
83__xray_FunctionTailExit:
84    PUSH {r1-r3,lr}
85    @ Save floating-point parameters of the instrumented function
86    VPUSH {d0-d7}
87    MOVW r1, #:lower16:_ZN6__xray19XRayPatchedFunctionE - (. + 16)
88    MOVT r1, #:upper16:_ZN6__xray19XRayPatchedFunctionE - (. + 12)
89    LDR r2, [pc, r1]
90    @ Handler address is nullptr if handler is not set
91    CMP r2, #0
92    BEQ FunctionTailExit_restore
93    @ Function ID is already in r0 (the first parameter).
94    @ r1=2 means that we are tracing a tail exit event
95    @ But before the logging part of XRay is ready, we pretend that here a
96    @   normal function exit happens, so we give the handler code 1
97    MOV r1, #1
98    @ Call the handler with 2 parameters in r0 and r1
99    BLX r2
100FunctionTailExit_restore:
101    @ Restore floating-point parameters of the instrumented function
102    VPOP {d0-d7}
103    POP {r1-r3,pc}
104
105NO_EXEC_STACK_DIRECTIVE
106