InlineAsm objects are not uniqued

[lattner]

Bugzilla Link	803
Resolution	FIXED
Resolved on	Mar 21, 2010 17:13
Version	1.0
OS	All
Blocks	llvm/llvm-bugzilla-archive#862

Extended Description

InlineAsm::get should memoize inline asm objects. This is a tracking bug so I don't forget about it.

This is slightly tricker than it looks because the map that memoizes the objects needs to be robust in the
face of type refinement (like the constant memoizer).

-Chris

[llvmbot]

Is this really needed? How much duplication is there in the typical program?

[lattner]

If you have one inline asm in a helper function (say to implement libm "sin"), it can get inlined many
places.

-Chris

[llvmbot]

And this causes memory leaks. Prefix the following command with valgrind --leak-check=full.

******************** TEST 'LLVM :: Assembler/alignstack.ll' FAILED ********************
Script:

llvm-as < /home/jyasskin/llvm/src/test/Assembler/alignstack.ll | llvm-dis | FileCheck /home/jyasskin/llvm/src/test/Assembler/alignstack.ll

Exit Code: 1
Command Output (stdout):

Command has output on stderr!

--
Command Output (stderr):

==11106== 576 (256 direct, 320 indirect) bytes in 4 blocks are definitely lost in loss record 14 of 14
==11106== at 0x4C229C7: operator new(unsigned long) (vg_replace_malloc.c:220)
==11106== by 0x4CBDA2: llvm::InlineAsm::get(llvm::FunctionType const*, llvm::StringRef, llvm::StringRef, bool, bool) (InlineAsm.cpp:34)
==11106== by 0x443FC3: llvm::LLParser::ConvertValIDToValue(llvm::Type const*, llvm::ValID&, llvm::Value*&, llvm::LLParser::PerFunctionState*) (LLParser.cpp:2492)
==11106== by 0x44AA7A: llvm::LLParser::ParseCall(llvm::Instruction*&, llvm::LLParser::PerFunctionState&, bool) (LLParser.cpp:3654)
==11106== by 0x4473BD: llvm::LLParser::ParseInstruction(llvm::Instruction*&, llvm::BasicBlock*, llvm::LLParser::PerFunctionState&) (LLParser.cpp:3028)
==11106== by 0x4469F0: llvm::LLParser::ParseBasicBlock(llvm::LLParser::PerFunctionState&) (LLParser.cpp:2892)
==11106== by 0x4466C8: llvm::LLParser::ParseFunctionBody(llvm::Function&) (LLParser.cpp:2843)
==11106== by 0x437C7C: llvm::LLParser::ParseDefine() (LLParser.cpp:392)
==11106== by 0x436996: llvm::LLParser::ParseTopLevelEntities() (LLParser.cpp:161)
==11106== by 0x435AD1: llvm::LLParser::Run() (LLParser.cpp:36)
==11106== by 0x42D6CB: llvm::ParseAssembly(llvm::MemoryBuffer*, llvm::Module*, llvm::SMDiagnostic&, llvm::LLVMContext&) (Parser.cpp:37)
==11106== by 0x42D91F: llvm::ParseAssemblyFile(std::string const&, llvm::SMDiagnostic&, llvm::LLVMContext&) (Parser.cpp:53)
==11106==

---

[llvmbot]

Patch to memoize InlineAsms into the LLVMContext
Nick suggested InlineAsms should be memoized per Module instead of for the whole Context. Putting them in the Context is easier, but the Module should be doable if people prefer.

This patch fixes the memory leak.

[llvmbot]

Fixed by r99143.

[asl]

mentioned in issue llvm/llvm-bugzilla-archive#862