[LLVMdev] gdb + clang/llvm
Jim Grosbach
grosbach at apple.com
Mon Apr 23 17:03:25 PDT 2012
Glad you got things sorted out. :)
--jim
On Apr 23, 2012, at 4:25 PM, Roland Leißa <leissa at cs.uni-saarland.de> wrote:
> Hi Jim,
>
> thanks for replying. As mentioned in my earlier mail, I have to specify -emit-obj along with -cc1 in order to trigger codegen. This solves the problem for me.
> As I learned from the last email, specifying -v is a good starting point in order to see what actually is happening and tackle such problems.
>
> --
> Roland
>
> ----- Original Message -----
>> From: "Jim Grosbach" <grosbach at apple.com>
>> To: "Roland Leißa" <leissa at cs.uni-saarland.de>
>> Cc: LLVMdev at cs.uiuc.edu
>> Sent: Montag, 23. April 2012 14:45:42
>> Subject: Re: [LLVMdev] gdb + clang/llvm
>>
>>
>> On Apr 23, 2012, at 2:14 PM, Roland Leißa <leissa at cs.uni-saarland.de>
>> wrote:
>>
>>>>> ok, I now have a problem in the code generator.
>>>>> Let's say I want to set a breakpoint somewhere in
>>>>> clang/lib/CodeGen/CGExprScalar.cpp
>>>>>
>>>>> What do I have to do in order to trigger breakpoints, see
>>>>> backtraces and so on?
>>>>
>>>> You set a breakpoint and ask to see a backtrace?
>>>>
>>>> -eric
>>>
>>> haha, OK, I think I should be more specific.
>>>
>>> So, I configured the project with:
>>> ../llvm/configure --prefix=PROJECT_DIR/install_debug
>>> --enable-expensive-checks --enable-targets=host
>>> --enable-debug-runtime --enable-shared CXX=g++ CC=gcc
>>>
>>> note that I'm using gcc
>>>
>>> then I run
>>> make
>>> make install
>>>
>>> next I fire up gdb
>>> setting a breakpoint somewhere in clang/lib/Sema only works if
>>> executing clang with -cc1
>>> Now the code generation of clang doesn't seem to happen just with
>>> -cc1, so I have to elide the switch when having problems somewhere
>>> in this area.
>>
>> Eh? Codegen most certainly should happen when run with cc1.
>>
>> Eliding the option is never the right choice when debugging, unless
>> you're debugging the driver itself.
>>
>>
>>> Let's say I have a problem in
>>> clang/lib/CodeGen/CGExprScalar.cpp, line 2742
>>> I put
>>> llvm::errs() << "test\n";
>>> there in order to verify that this line is really getting executed.
>>> Then, I set the breakpoint
>>> break CGExprScalar.cpp :2742
>>> and run clang:
>>> r -std=c++11 simple.cpp
>>>
>>>
>>> I'm getting this output:
>>>
>>> Starting program:
>>> /home/rleissa/projects/test/build_debug/Debug+Asserts+Checks/bin/clang
>>> -std=c++11 simple.cpp
>>> [Thread debugging using libthread_db enabled]
>>> Using host libthread_db library "/lib/libthread_db.so.1".
>>> test
>>> clang:
>>> /home/rleissa/projects/test/llvm/lib/VMCore/Instructions.cpp:1475:
>>> llvm::InsertElementInst::InsertElementInst(llvm::Value*,
>>> llvm::Value*, llvm::Value*, const llvm::Twine&,
>>> llvm::Instruction*): Assertion `isValidOperands(Vec, Elt, Index)
>>> && "Invalid insertelement instruction operands!"' failed.
>>> 0 libLLVM-3.2svn.so 0x00007ffff686f9bd
>>> 1 libLLVM-3.2svn.so 0x00007ffff686f715
>>> 2 libpthread.so.0 0x00007ffff586f140
>>> 3 libc.so.6 0x00007ffff4ae1c35 gsignal + 53
>>> 4 libc.so.6 0x00007ffff4ae30b8 abort + 328
>>> 5 libc.so.6 0x00007ffff4adac12
>>> 6 libc.so.6 0x00007ffff4adacc2
>>> 7 libLLVM-3.2svn.so 0x00007ffff6a1a7b3
>>> llvm::InsertElementInst::InsertElementInst(llvm::Value*,
>>> llvm::Value*, llvm::Value*, llvm::Twine const&,
>>> llvm::Instruction*) + 175
>>> 8 clang 0x0000000000b64b35
>>> 9 clang 0x0000000000b66e5e
>>> 10 clang 0x0000000000b997b7
>>> 11 clang 0x0000000000ba386d
>>> 12 clang 0x0000000000ba2c91
>>> 13 clang 0x0000000000b9496d
>>> 14 clang 0x0000000000ba1a40
>>> clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr
>>> const*, bool) + 176
>>> 15 clang 0x0000000000c03875
>>> clang::CodeGen::CodeGenFunction::EmitReturnStmt(clang::ReturnStmt
>>> const&) + 683
>>> 16 clang 0x0000000000c01084
>>> clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*) +
>>> 742
>>> 17 clang 0x0000000000c014ff
>>> clang::CodeGen::CodeGenFunction::EmitCompoundStmt(clang::CompoundStmt
>>> const&, bool, clang::CodeGen::AggValueSlot) + 241
>>> 18 clang 0x0000000000c012d6
>>> clang::CodeGen::CodeGenFunction::EmitSimpleStmt(clang::Stmt
>>> const*) + 226
>>> 19 clang 0x0000000000c00de9
>>> clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*) + 75
>>> 20 clang 0x0000000000c19808
>>> clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::CodeGen::FunctionArgList&)
>>> + 154
>>> 21 clang 0x0000000000c19d11
>>> clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl,
>>> llvm::Function*, clang::CodeGen::CGFunctionInfo const&) + 971
>>> 22 clang 0x0000000000a9025f
>>> clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl)
>>> + 847
>>> 23 clang 0x0000000000a8d2c3
>>> clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl)
>>> + 445
>>> 24 clang 0x0000000000a8cbd2
>>> clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) + 754
>>> 25 clang 0x0000000000a932ba
>>> clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) +
>>> 320
>>> 26 clang 0x0000000000a8628f
>>> 27 clang 0x0000000000a8444c
>>> 28 clang 0x0000000000c40b68
>>> clang::ParseAST(clang::Sema&, bool, bool) + 453
>>> 29 clang 0x00000000008c4dfc
>>> clang::ASTFrontendAction::ExecuteAction() + 298
>>> 30 clang 0x0000000000a839bc
>>> clang::CodeGenAction::ExecuteAction() + 1200
>>> 31 clang 0x00000000008c4a31
>>> clang::FrontendAction::Execute() + 245
>>> 32 clang 0x00000000008982ec
>>> clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) +
>>> 718
>>> 33 clang 0x000000000085f3bc
>>> clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 1011
>>> 34 clang 0x0000000000847bc1 cc1_main(char const**, char
>>> const**, char const*, void*) + 987
>>> 35 clang 0x0000000000857ee7 main + 555
>>> 36 libc.so.6 0x00007ffff4ace455 __libc_start_main + 245
>>> 37 clang 0x0000000000846ca9
>>> Stack dump:
>>> 0. Program arguments:
>>> /home/rleissa/projects/test/build_debug/Debug+Asserts+Checks/bin/clang
>>> -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all
>>> -disable-free -main-file-name simple.cpp -mrelocation-model static
>>> -mdisable-fp-elim -masm-verbose -mconstructor-aliases
>>> -munwind-tables -target-cpu x86-64 -target-linker-version
>>> 2.22.0.20120323 -momit-leaf-frame-pointer -resource-dir
>>> /home/rleissa/projects/test/build_debug/Debug+Asserts+Checks/bin/../lib/clang/3.2
>>> -fmodule-cache-path /var/tmp/clang-module-cache -internal-isystem
>>> /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0
>>> -internal-isystem
>>> /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/x86_64-unknown-linux-gnu
>>> -internal-isystem
>>> /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/backward
>>> -internal-isystem /usr/local/include -internal-isystem
>>> /home/rleissa/projects/test/build_debug/Debug+Asserts+Checks/bin/../lib/clang/3.2/include
>>> -internal-e!
>>> xternc-isystem /include -internal-externc-isystem /usr/include
>>> -std=c++11 -fdeprecated-macro -fdebug-compilation-dir
>>> /home/rleissa/projects/test/libtest -ferror-limit 19
>>> -fmessage-length 274 -mstackrealign -fgnu-runtime
>>> -fobjc-runtime-has-arc -fobjc-runtime-has-weak -fobjc-fragile-abi
>>> -fcxx-exceptions -fexceptions -fdiagnostics-show-option
>>> -fcolor-diagnostics -o /tmp/simple-QlxJIj.o -x c++ simple.cpp
>>> 1. <eof> parser at end of file
>>> 2. simple.cpp:22:14: LLVM IR generation of declaration 'test'
>>> 3. simple.cpp:22:14: Generating code for declaration 'test'
>>> 4. simple.cpp:22:53: LLVM IR generation of compound statement
>>> ('{}')
>>> clang: error: unable to execute command: Aborted
>>> clang: error: clang frontend command failed due to signal (use -v
>>> to see invocation)
>>> clang: note: diagnostic msg: Please submit a bug report to
>>> http://llvm.org/bugs/ and include command line arguments and all
>>> diagnostic information.
>>> clang: note: diagnostic msg: Preprocessed source(s) and associated
>>> run script(s) are located at:
>>> clang: note: diagnostic msg: /tmp/simple-Rkocwp.ii
>>> clang: note: diagnostic msg: /tmp/simple-Rkocwp.sh
>>> [Inferior 1 (process 8392) exited with code 0376]
>>>
>>>
>>> As you can see the line is question is executed but the breakpoint
>>> is not triggered. Apparently, clang executes the code generation
>>> in a different process. What do I have to do in order to debug
>>> this process?
>>>
>>> --
>>> Roland
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>
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