Implement ARM GNU-style interrupt attribute
This attribute allows users to use a modified C or C++ function as an ARM
exception-handling function and, with care, to successfully return control to
user-space after the issue has been dealt with.
rdar://problem/14207019
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191769 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index 0706a28..01efd11 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -3056,9 +3056,9 @@
Env == "android" || Env == "androideabi");
}
-private:
ABIKind getABIKind() const { return Kind; }
+private:
ABIArgInfo classifyReturnType(QualType RetTy) const;
ABIArgInfo classifyArgumentType(QualType RetTy, int *VFPRegs,
unsigned &AllocatedVFP,
@@ -3105,6 +3105,45 @@
if (getABIInfo().isEABI()) return 88;
return TargetCodeGenInfo::getSizeOfUnwindException();
}
+
+ void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
+ CodeGen::CodeGenModule &CGM) const {
+ const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
+ if (!FD)
+ return;
+
+ const ARMInterruptAttr *Attr = FD->getAttr<ARMInterruptAttr>();
+ if (!Attr)
+ return;
+
+ const char *Kind;
+ switch (Attr->getInterrupt()) {
+ case ARMInterruptAttr::Generic: Kind = ""; break;
+ case ARMInterruptAttr::IRQ: Kind = "IRQ"; break;
+ case ARMInterruptAttr::FIQ: Kind = "FIQ"; break;
+ case ARMInterruptAttr::SWI: Kind = "SWI"; break;
+ case ARMInterruptAttr::ABORT: Kind = "ABORT"; break;
+ case ARMInterruptAttr::UNDEF: Kind = "UNDEF"; break;
+ }
+
+ llvm::Function *Fn = cast<llvm::Function>(GV);
+
+ Fn->addFnAttr("interrupt", Kind);
+
+ if (cast<ARMABIInfo>(getABIInfo()).getABIKind() == ARMABIInfo::APCS)
+ return;
+
+ // AAPCS guarantees that sp will be 8-byte aligned on any public interface,
+ // however this is not necessarily true on taking any interrupt. Instruct
+ // the backend to perform a realignment as part of the function prologue.
+ llvm::AttrBuilder B;
+ B.addStackAlignmentAttr(8);
+ Fn->addAttributes(llvm::AttributeSet::FunctionIndex,
+ llvm::AttributeSet::get(CGM.getLLVMContext(),
+ llvm::AttributeSet::FunctionIndex,
+ B));
+ }
+
};
}