f9fd0062b6
`__xray_customevent` and `__xray_typedevent` are built-in functions in Clang.
With -fxray-instrument, they are lowered to intrinsics llvm.xray.customevent and
llvm.xray.typedevent, respectively. These intrinsics are then lowered to
TargetOpcode::{PATCHABLE_EVENT_CALL,PATCHABLE_TYPED_EVENT_CALL}. The target is
responsible for generating a code sequence that calls either
`__xray_CustomEvent` (with 2 arguments) or `__xray_TypedEvent` (with 3
arguments).
Before patching, the code sequence is prefixed by a branch instruction that
skips the rest of the code sequence. After patching
(compiler-rt/lib/xray/xray_AArch64.cpp), the branch instruction becomes a NOP
and the function call will take effects.
This patch implements the lowering process for
{PATCHABLE_EVENT_CALL,PATCHABLE_TYPED_EVENT_CALL} and implements the runtime.
```
// Lowering of PATCHABLE_EVENT_CALL
.Lxray_sled_N:
b #24
stp x0, x1, [sp, #-16]!
x0 = reg of op0
x1 = reg of op1
bl __xray_CustomEvent
ldrp x0, x1, [sp], #16
```
As a result, two updated tests in compiler-rt/test/xray/TestCases/Posix/ now
pass on AArch64.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D153320
43 lines
1.6 KiB
C++
43 lines
1.6 KiB
C++
// Use the clang feature for custom xray event logging.
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//
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// RUN: %clangxx_xray -std=c++11 %s -o %t
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// RUN: XRAY_OPTIONS="patch_premain=false verbosity=1 xray_logfile_base=custom-event-logging.xray-" %run %t 2>&1 | FileCheck %s
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// RUN: %clangxx_xray -std=c++11 -fpic -fpie %s -o %t
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// RUN: XRAY_OPTIONS="patch_premain=false verbosity=1 xray_logfile_base=custom-event-logging.xray-" %run %t 2>&1 | FileCheck %s
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// FIXME: Support this in non-x86_64 as well
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// REQUIRES: target={{(aarch64|x86_64)-.*linux.*}}
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// REQUIRES: built-in-llvm-tree
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#include <cstdio>
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#include "xray/xray_interface.h"
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[[clang::xray_always_instrument]] void foo() {
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static constexpr char CustomLogged[] = "hello custom logging!";
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printf("before calling the custom logging...\n");
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__xray_customevent(CustomLogged, sizeof(CustomLogged));
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printf("after calling the custom logging...\n");
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}
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void myprinter(void* ptr, size_t size) {
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printf("%.*s\n", static_cast<int>(size), static_cast<const char*>(ptr));
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}
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int main() {
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foo();
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// CHECK: before calling the custom logging...
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// CHECK-NEXT: after calling the custom logging...
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printf("setting up custom event handler...\n");
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// CHECK-NEXT: setting up custom event handler...
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__xray_set_customevent_handler(myprinter);
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__xray_patch();
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// CHECK-NEXT: before calling the custom logging...
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foo();
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// CHECK-NEXT: hello custom logging!
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// CHECK-NEXT: after calling the custom logging...
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printf("removing custom event handler...\n");
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// CHECK-NEXT: removing custom event handler...
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__xray_remove_customevent_handler();
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foo();
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// CHECK-NEXT: before calling the custom logging...
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// CHECK-NEXT: after calling the custom logging...
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}
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