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[clang][AArch64] Move initialization of ptrauth-* function attrs (#140277)

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Move the initialization of ptrauth-* function attributes near the
initialization of branch protection attributes. The semantics of these
groups of attributes partially overlaps, so handle both groups in
getDefaultFunctionAttributes() and setTargetAttributes() functions to
prevent getting them out of sync. This fixes C++ TLS wrappers.
This commit is contained in:
Anatoly Trosinenko 2025-05-20 12:50:58 +03:00 committed by GitHub
parent c9d6249198
commit f10a90587f
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GPG Key ID: B5690EEEBB952194
6 changed files with 54 additions and 16 deletions
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5
clang/lib/CodeGen/CGCall.cpp
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@ -2216,6 +2216,11 @@ void CodeGenModule::getDefaultFunctionAttributes(StringRef Name,
llvm::AttrBuilder &FuncAttrs) {
getTrivialDefaultFunctionAttributes(Name, HasOptnone, AttrOnCallSite,
FuncAttrs);
if (!AttrOnCallSite)
TargetCodeGenInfo::initPointerAuthFnAttributes(CodeGenOpts.PointerAuth,
FuncAttrs);
// If we're just getting the default, get the default values for mergeable
// attributes.
if (!AttrOnCallSite)

13
clang/lib/CodeGen/CodeGenFunction.cpp
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@ -890,19 +890,6 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
FD->getBody()->getStmtClass() == Stmt::CoroutineBodyStmtClass)
SanOpts.Mask &= ~SanitizerKind::Null;
// Add pointer authentication attributes.
const CodeGenOptions &CodeGenOpts = CGM.getCodeGenOpts();
if (CodeGenOpts.PointerAuth.ReturnAddresses)
Fn->addFnAttr("ptrauth-returns");
if (CodeGenOpts.PointerAuth.FunctionPointers)
Fn->addFnAttr("ptrauth-calls");
if (CodeGenOpts.PointerAuth.AuthTraps)
Fn->addFnAttr("ptrauth-auth-traps");
if (CodeGenOpts.PointerAuth.IndirectGotos)
Fn->addFnAttr("ptrauth-indirect-gotos");
if (CodeGenOpts.PointerAuth.AArch64JumpTableHardening)
Fn->addFnAttr("aarch64-jump-table-hardening");
// Apply xray attributes to the function (as a string, for now)
bool AlwaysXRayAttr = false;
if (const auto *XRayAttr = D ? D->getAttr<XRayInstrumentAttr>() : nullptr) {

29
clang/lib/CodeGen/TargetInfo.cpp
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@ -258,6 +258,35 @@ void TargetCodeGenInfo::initBranchProtectionFnAttributes(
FuncAttrs.addAttribute("guarded-control-stack");
}
void TargetCodeGenInfo::setPointerAuthFnAttributes(
const PointerAuthOptions &Opts, llvm::Function &F) {
auto UpdateAttr = [&F](bool AttrShouldExist, StringRef AttrName) {
if (AttrShouldExist && !F.hasFnAttribute(AttrName))
F.addFnAttr(AttrName);
if (!AttrShouldExist && F.hasFnAttribute(AttrName))
F.removeFnAttr(AttrName);
};
UpdateAttr(Opts.ReturnAddresses, "ptrauth-returns");
UpdateAttr((bool)Opts.FunctionPointers, "ptrauth-calls");
UpdateAttr(Opts.AuthTraps, "ptrauth-auth-traps");
UpdateAttr(Opts.IndirectGotos, "ptrauth-indirect-gotos");
UpdateAttr(Opts.AArch64JumpTableHardening, "aarch64-jump-table-hardening");
}
void TargetCodeGenInfo::initPointerAuthFnAttributes(
const PointerAuthOptions &Opts, llvm::AttrBuilder &FuncAttrs) {
if (Opts.ReturnAddresses)
FuncAttrs.addAttribute("ptrauth-returns");
if (Opts.FunctionPointers)
FuncAttrs.addAttribute("ptrauth-calls");
if (Opts.AuthTraps)
FuncAttrs.addAttribute("ptrauth-auth-traps");
if (Opts.IndirectGotos)
FuncAttrs.addAttribute("ptrauth-indirect-gotos");
if (Opts.AArch64JumpTableHardening)
FuncAttrs.addAttribute("aarch64-jump-table-hardening");
}
namespace {
class DefaultTargetCodeGenInfo : public TargetCodeGenInfo {
public:

9
clang/lib/CodeGen/TargetInfo.h
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@ -459,6 +459,15 @@ public:
initBranchProtectionFnAttributes(const TargetInfo::BranchProtectionInfo &BPI,
llvm::AttrBuilder &FuncAttrs);
// Set the ptrauth-* attributes of the Function accordingly to the Opts.
// Remove attributes that contradict with current Opts.
static void setPointerAuthFnAttributes(const PointerAuthOptions &Opts,
llvm::Function &F);
// Add the ptrauth-* Attributes to the FuncAttrs.
static void initPointerAuthFnAttributes(const PointerAuthOptions &Opts,
llvm::AttrBuilder &FuncAttrs);
protected:
static std::string qualifyWindowsLibrary(StringRef Lib);

1
clang/lib/CodeGen/Targets/AArch64.cpp
View File

@ -155,6 +155,7 @@ public:
}
}
setBranchProtectionFnAttributes(BPI, *Fn);
setPointerAuthFnAttributes(CGM.getCodeGenOpts().PointerAuth, *Fn);
}
bool isScalarizableAsmOperand(CodeGen::CodeGenFunction &CGF,

13
clang/test/CodeGenCXX/arm64-generated-fn-attr.cpp
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@ -1,4 +1,9 @@
// RUN: %clang_cc1 -triple aarch64 -mbranch-target-enforce -msign-return-address=all -fcxx-exceptions -fexceptions -emit-llvm %s -o - | FileCheck %s
// RUN: %clang_cc1 -triple aarch64 -mbranch-target-enforce -msign-return-address=all \
// RUN: -fcxx-exceptions -fexceptions -emit-llvm %s -o - \
// RUN: | FileCheck --check-prefixes=CHECK,BTE-SIGNRA %s
// RUN: %clang_cc1 -triple aarch64 -fptrauth-calls -fptrauth-returns -fptrauth-auth-traps -fptrauth-indirect-gotos \
// RUN: -fcxx-exceptions -fexceptions -emit-llvm %s -o - \
// RUN: | FileCheck --check-prefixes=CHECK,PAUTHTEST %s
// Check that functions generated by clang have the correct attributes
@ -26,5 +31,7 @@ int testfn() noexcept {
// CHECK: define {{.*}} @_ZTW4var2() [[ATTR1]]
// CHECK: define {{.*}} @__tls_init() [[ATTR1]]
// CHECK: attributes [[ATTR1]] = { {{.*}}"branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
// CHECK: attributes [[ATTR2]] = { {{.*}}"branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
// BTE-SIGNRA: attributes [[ATTR1]] = { {{.*}}"branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
// BTE-SIGNRA: attributes [[ATTR2]] = { {{.*}}"branch-target-enforcement" {{.*}}"sign-return-address"="all" "sign-return-address-key"="a_key"
// PAUTHTEST: attributes [[ATTR1]] = { {{.*}}"ptrauth-auth-traps" "ptrauth-calls" "ptrauth-indirect-gotos" "ptrauth-returns"
// PAUTHTEST: attributes [[ATTR2]] = { {{.*}}"ptrauth-auth-traps" "ptrauth-calls" "ptrauth-indirect-gotos" "ptrauth-returns"