llvm-project/clang/test/CodeGen/default-function-attr.c

// RUN: %clang_cc1 -default-function-attr foo=bar -emit-llvm %s -o - | FileCheck %s

// CHECK: define void @foo() #[[X:[0-9]+]]
void foo() {}

// CHECK: attributes #[[X]] = {{.*}} "foo"="bar"
hwasan: Implement lazy thread initialization for the interceptor ABI. The problem is similar to D55986 but for threads: a process with the interceptor hwasan library loaded might have some threads started by instrumented libraries and some by uninstrumented libraries, and we need to be able to run instrumented code on the latter. The solution is to perform per-thread initialization lazily. If a function needs to access shadow memory or add itself to the per-thread ring buffer its prologue checks to see whether the value in the sanitizer TLS slot is null, and if so it calls __hwasan_thread_enter and reloads from the TLS slot. The runtime does the same thing if it needs to access this data structure. This change means that the code generator needs to know whether we are targeting the interceptor runtime, since we don't want to pay the cost of lazy initialization when targeting a platform with native hwasan support. A flag -fsanitize-hwaddress-abi={interceptor,platform} has been introduced for selecting the runtime ABI to target. The default ABI is set to interceptor since it's assumed that it will be more common that users will be compiling application code than platform code. Because we can no longer assume that the TLS slot is initialized, the pthread_create interceptor is no longer necessary, so it has been removed. Ideally, lazy initialization should only cost one instruction in the hot path, but at present the call may cause us to spill arguments to the stack, which means more instructions in the hot path (or theoretically in the cold path if the spills are moved with shrink wrapping). With an appropriately chosen calling convention for the per-thread initialization function (TODO) the hot path should always need just one instruction and the cold path should need two instructions with no spilling required. Differential Revision: https://reviews.llvm.org/D56038 llvm-svn: 350429 2019-01-05 03:27:04 +08:00			`// RUN: %clang_cc1 -default-function-attr foo=bar -emit-llvm %s -o - \| FileCheck %s`

			`// CHECK: define void @foo() #[[X:[0-9]+]]`
			`void foo() {}`

			`// CHECK: attributes #[[X]] = {{.*}} "foo"="bar"`