bjoernager/rust
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Add emulated TLS support

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Currently LLVM uses emutls by default
for some targets (such as android, openbsd),
but rust does not use it, because `has_thread_local` is false.

This commit has some changes to allow users to enable emutls:

1. add `-Zhas-thread-local` flag to specify
    that std uses `#[thread_local]` instead of pthread key.
2. when using emutls, decorate symbol names
    to find thread local symbol correctly.
3. change `-Zforce-emulated-tls` to `-Ztls-model=emulated`
    to explicitly specify whether to generate emutls.
This commit is contained in:
quininer 2023-11-13 20:48:23 +08:00
parent 8a7b2035f8
commit e5b76892cc
17 changed files with 71 additions and 28 deletions
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10
compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
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@ -410,7 +410,7 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
const char *SplitDwarfFile,
const char *OutputObjFile,
const char *DebugInfoCompression,
bool ForceEmulatedTls,
bool UseEmulatedTls,
const char *ArgsCstrBuff, size_t ArgsCstrBuffLen) {
auto OptLevel = fromRust(RustOptLevel);
@ -456,13 +456,9 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
Options.UseInitArray = UseInitArray;
#if LLVM_VERSION_LT(17, 0)
if (ForceEmulatedTls) {
Options.ExplicitEmulatedTLS = true;
Options.EmulatedTLS = true;
}
#else
Options.EmulatedTLS = ForceEmulatedTls || Trip.hasDefaultEmulatedTLS();
Options.ExplicitEmulatedTLS = true;
#endif
Options.EmulatedTLS = UseEmulatedTls;
if (TrapUnreachable) {
// Tell LLVM to codegen `unreachable` into an explicit trap instruction.