Hi, everyone. I want to writing a Pass to get the variable value while the program is running ,the basic idea is to insert an STL map in the program ,and get every value and address a program use ,but whether it's possible to do this by transforming the llvm IR? I didn't find any useful functions to get a variable's address in LLVM IR .It seems that the IR is an SSA form and we can not get a value's address in compiling time.Is that right? But how can I dynamically get the variable's value in run time by writing a Pass ? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140102/160f83d3/attachment.html>
One way, and most likely the easiest, is to write/use a library that does what you want and then write an LLVM IR pass that inserts function calls to execute at runtime and link in your library. Micah From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Jin Huang Sent: Wednesday, January 01, 2014 9:39 PM To: llvmdev at cs.uiuc.edu Subject: [LLVMdev] Tracing values in llvm IR Hi, everyone. I want to writing a Pass to get the variable value while the program is running ,the basic idea is to insert an STL map in the program ,and get every value and address a program use ,but whether it's possible to do this by transforming the llvm IR? I didn't find any useful functions to get a variable's address in LLVM IR .It seems that the IR is an SSA form and we can not get a value's address in compiling time.Is that right? But how can I dynamically get the variable's value in run time by writing a Pass ? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140102/cc6802b1/attachment.html>
On 1/1/14 11:39 PM, Jin Huang wrote:> Hi, everyone. > > I want to writing a Pass to get the variable value while the program > is running ,the basic idea is to insert an STL map in the program ,and > get every value and address a program use ,but whether it's possible > to do this by transforming the llvm IR? > > I didn't find any useful functions to get a variable's address in LLVM > IR .It seems that the IR is an SSA form and we can not get a value's > address in compiling time.Is that right? But how can I dynamically get > the variable's value in run time by writing a Pass ?The giri project does dynamic tracing of values stored to and loaded from memory. It stores the trace of memory accesses on disk because they get very large very quickly. You can either reuse the Giri code or modify it to suit your purposes. Swarup, is there a place where people can download the updated Giri code that your Google Summer of Code student worked on? -- John T.> > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140102/0232c3f4/attachment.html>
Hi Jin Huang, The updated Giri code is available at https://github.com/liuml07/giri<https://github.com/liuml07/giri.>. This will give you an idea of how to instrument the program to trace different values. You can modify the code to achieve your goals. -Swarup. ________________________________ From: Criswell, John T Sent: Thursday, January 02, 2014 2:12 PM To: Jin Huang; llvmdev at cs.uiuc.edu; Sahoo, Swarup Kumar Subject: Re: [LLVMdev] Tracing values in llvm IR On 1/1/14 11:39 PM, Jin Huang wrote: Hi, everyone. I want to writing a Pass to get the variable value while the program is running ,the basic idea is to insert an STL map in the program ,and get every value and address a program use ,but whether it's possible to do this by transforming the llvm IR? I didn't find any useful functions to get a variable's address in LLVM IR .It seems that the IR is an SSA form and we can not get a value's address in compiling time.Is that right? But how can I dynamically get the variable's value in run time by writing a Pass ? The giri project does dynamic tracing of values stored to and loaded from memory. It stores the trace of memory accesses on disk because they get very large very quickly. You can either reuse the Giri code or modify it to suit your purposes. Swarup, is there a place where people can download the updated Giri code that your Google Summer of Code student worked on? -- John T. _______________________________________________ LLVM Developers mailing list LLVMdev at cs.uiuc.edu<mailto:LLVMdev at cs.uiuc.edu> http://llvm.cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140102/fc494647/attachment.html>