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Fixing PR21811 by applying attributes to global init function
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Authored by ygao on Apr 22 2015, 11:03 AM.

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Reviewers: None
Commits: rG787dc438c9ce: Set normal LLVM function attributes on global initializer functions
rC235537: Set normal LLVM function attributes on global initializer functions
rL235537: Set normal LLVM function attributes on global initializer functions

Summary

Hi,
This patch attempts to fix bug#21811 by attaching the no-frame-pointer-elim-non-leaf
attribute to the compiler-created global init function. It would be helpful if
someone can review this,

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Event Timeline

ygao updated this revision to Diff 24245.Apr 22 2015, 11:03 AM

ygao retitled this revision from to Fixing PR21811 by applying attributes to global init function.

ygao updated this object.

ygao edited the test plan for this revision. (Show Details)

ygao added subscribers: Unknown Object (MLST), rnk.

This isn't enough, there are other bugs here. We should be arranging a CGFunctionInfo and calling SetLLVMFunctionAttributes.

Closed by commit rL235537: Set normal LLVM function attributes on global initializer functions (authored by rnk). · Explain WhyApr 22 2015, 12:40 PM

This revision was automatically updated to reflect the committed changes.

I went ahead and landed a slightly different version in r235537. Thanks for the patch!

Thanks!
What do you think we should do regarding the related no-frame-pointer-elim attribute? Right now it is set by the frontend but not checked by backend. If I follow the same pattern here, we should get rid of the global flag NoFramePointerElim and move to checking the attribute instead. What do you think?

Revision Contents

Path

Size

lib/

CodeGen/

CGDeclCXX.cpp

4 lines

test/

CodeGenCXX/

global-init.cpp

8 lines

Diff 24245

lib/CodeGen/CGDeclCXX.cpp

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	if (getLangOpts().Sanitize.has(SanitizerKind::Memory))	if (getLangOpts().Sanitize.has(SanitizerKind::Memory))
	Fn->addFnAttr(llvm::Attribute::SanitizeMemory);	Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
	}	}

		if (getCodeGenOpts().DisableFPElim &&
		getCodeGenOpts().OmitLeafFramePointer)
		Fn->addFnAttr("no-frame-pointer-elim-non-leaf");

	return Fn;	return Fn;
	}	}
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test/CodeGenCXX/global-init.cpp

	// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm -fexceptions %s -o - \|FileCheck %s	// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm -fexceptions %s -o - \|FileCheck %s
	// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm %s -o - \|FileCheck -check-prefix CHECK-NOEXC %s	// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm %s -o - \|FileCheck -check-prefix CHECK-NOEXC %s

		// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm \
		// RUN: -momit-leaf-frame-pointer -mdisable-fp-elim %s -o - \
		// RUN: \| FileCheck -check-prefix CHECK-FP %s

	struct A {	struct A {
	A();	A();
	~A();	~A();
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	// CHECK-NOEXC: define internal void @_GLOBAL__sub_I_global_init.cpp() [[NUW:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {	// CHECK-NOEXC: define internal void @_GLOBAL__sub_I_global_init.cpp() [[NUW:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {

	// CHECK-NOEXC: attributes [[NUW]] = { nounwind }	// CHECK-NOEXC: attributes [[NUW]] = { nounwind }

		// PR21811: attach the appropriate attribute to the global init function
		// CHECK-FP: define internal void @_GLOBAL__sub_I_global_init.cpp() [[NUX:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {
		// CHECK-FP: attributes [[NUX]] = { nounwind "no-frame-pointer-elim-non-leaf" }
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