[lldb-dev] No machine instructions loaded for symbols or target (python api)
Hi, I'm building an application on windows using the python api. I need to be able to access a code symbols instructions but when I launch the process the symbol has no instructions. I can manually read the symbols address space but the symbol also has no end_addr set which makes it difficult to tell where the symbol ends . Can anybody help me to find out how to generate the instructions when the process is loaded ? cheers, Que ___ lldb-dev mailing list lldb-dev@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
Re: [lldb-dev] No machine instructions loaded for symbols or target (python api)
Ok I see what you're saying. I was trying to use the next symbol address as a delimeter but I realised they were not in order. It is a PECOFF binary that I'm debugging so I will take a look at the code suggested below. Thanks , Que On 17/11/15 18:07, Greg Clayton wrote: It sounds like the symbols in the symbol table don't have valid sizes when they really should. What kind of executable are you debugging? A PECOFF file? If so, you should take a look at and fix the code in: Symtab * ObjectFilePECOFF::GetSymtab() What we do for mach-o is to parse the symbol table first and then run back through all symbols, and any symbol that have a size of zero, set their sizes to the delta between the current symbol and the next addressed symbol. Since the symbols are usually out of order address wise, we run through all symbols that have addresses and add their indexes to a std::vector, then sort the vector of address indexes, and then we can do the above fixups. Greg Clayton On Nov 17, 2015, at 4:21 AM, kwadwo amankwa via lldb-dev <lldb-dev@lists.llvm.org> wrote: Hi, I'm building an application on windows using the python api. I need to be able to access a code symbols instructions but when I launch the process the symbol has no instructions. I can manually read the symbols address space but the symbol also has no end_addr set which makes it difficult to tell where the symbol ends . Can anybody help me to find out how to generate the instructions when the process is loaded ? cheers, Que ___ lldb-dev mailing list lldb-dev@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev ___ lldb-dev mailing list lldb-dev@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
Re: [lldb-dev] How to disassemble a section (python api)?
On 13/11/15 19:31, Greg Clayton wrote:
Currently you can't disassemble a section, nor would you probably want to since
there are padding bytes in between functions.
The easiest way is to get all SBSymbol objects and ask each one for the
instructions if they are code:
(lldb) script
Python Interactive Interpreter. To exit, type 'quit()', 'exit()' or Ctrl-D.
module = lldb.target.module['a.out']
num_symbols = module.GetNumSymbols()
for i in range(num_symbols):
... symbol = module.GetSymbolAtIndex(i)
... if symbol.GetType() == lldb.eSymbolTypeCode:
... print symbol
... instructions = symbol.GetInstructions(lldb.target)
... for inst in instructions:
... print inst
...
id = {0x0004}, range = [0x00010f00-0x00010f20), name="foo(float)",
mangled="_Z3foof"
a.out[0x10f00]: pushq %rbp
a.out[0x10f01]: movq %rsp, %rbp
a.out[0x10f04]: movss %xmm0, -0x4(%rbp)
a.out[0x10f09]: cvttss2si -0x4(%rbp), %eax
a.out[0x10f0e]: shll $0x1, %eax
a.out[0x10f11]: popq %rbp
a.out[0x10f12]: retq
a.out[0x10f13]: nopw %cs:(%rax,%rax)
id = {0x0008}, range = [0x00010f20-0x00010f40), name="foo(int)",
mangled="_Z3fooi"
a.out[0x10f20]: pushq %rbp
a.out[0x10f21]: movq %rsp, %rbp
a.out[0x10f24]: movl %edi, -0x4(%rbp)
a.out[0x10f27]: movl -0x4(%rbp), %edi
a.out[0x10f2a]: shll $0x2, %edi
a.out[0x10f2d]: movl %edi, %eax
a.out[0x10f2f]: popq %rbp
a.out[0x10f30]: retq
a.out[0x10f31]: nopw %cs:(%rax,%rax)
id = {0x000c}, range = [0x00010f40-0x00010f90), name="main"
a.out[0x10f40]: pushq %rbp
a.out[0x10f41]: movq %rsp, %rbp
a.out[0x10f44]: subq $0x30, %rsp
a.out[0x10f48]: movss 0x40(%rip), %xmm0
a.out[0x10f50]: movl $0x0, -0x4(%rbp)
a.out[0x10f57]: movl %edi, -0x8(%rbp)
a.out[0x10f5a]: movq %rsi, -0x10(%rbp)
a.out[0x10f5e]: movq %rdx, -0x18(%rbp)
a.out[0x10f62]: movss %xmm0, -0x1c(%rbp)
a.out[0x10f67]: movl $0x4d2, -0x20(%rbp)
a.out[0x10f6e]: movss -0x1c(%rbp), %xmm0
a.out[0x10f73]: callq 0x10f00
a.out[0x10f78]: movl -0x20(%rbp), %edi
a.out[0x10f7b]: movl %eax, -0x24(%rbp)
a.out[0x10f7e]: callq 0x10f20
a.out[0x10f83]: movl -0x24(%rbp), %edi
a.out[0x10f86]: addl %eax, %edi
a.out[0x10f88]: movl %edi, %eax
a.out[0x10f8a]: addq $0x30, %rsp
a.out[0x10f8e]: popq %rbp
a.out[0x10f8f]: retq
If you want the symbols only from a specific section you can get the section
from the symbol's start address and compare that to a given name:
section_name = ".text"
for i in range(num_symbols):
symbol = module.GetSymbolAtIndex(i)
if symbol.GetType() == lldb.eSymbolTypeCode:
symbol_section = symbol.GetStartAddress().GetSection()
if symbol_section.GetName() == section_name:
print symbol
instructions = symbol.GetInstructions(lldb.target)
for inst in instructions:
print inst
On Nov 12, 2015, at 2:13 PM, kwadwo amankwa via lldb-dev
<lldb-dev@lists.llvm.org> wrote:
Hi
I'm writing a small script and need to disassemble a whole section , what would
be the correct way to go about it ?
Cheers Que,
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Re: [lldb-dev] " Import error: No module named embedded_interpreter" on windows
e you using MSBuild or Ninja to build (i.e. are you
clicking the Build Solution button in Visual Studio or
running ninja from command line)? I don't know where it
puts this stuff with a VS2013 build, but with a ninja build,
your directory will be organized like this:
build
|___bin
|___lldb.exe
|___liblldb.dll
|___lib
|___site-packages
|___lldb
|___lldb_d.pyd // If this is a debug
build, lldb.pyd if release
I'm betting you're missing the pyd file. Can you confirm?
Then we can diagnose that if it turns out to be the problem.
On Mon, Oct 5, 2015 at 5:20 AM kwadwo amankwa via lldb-dev
<lldb-dev@lists.llvm.org <mailto:lldb-dev@lists.llvm.org>>
wrote:
Hi guys,
Can someone point me in the right direction on this . I
have managed to
set up my environment on windows , compiling
python2.7.10 using VS2013
and building llvm/lldb in VS2013. lldb and all its
libraries build
successfully so its just when I import lldb into my
python project I get
this error.
File "", line 1, in
Import error: No module named embedded_interpreter
Also when I use the 'script' command in the lldb
interpreter , lldb
completely crashes with an unhandled exception in the
python
file_write function (fileobject.c:1852)
n2 = fwrite(s, 1, n, f->f_fp);
the call to fwrite causes an access violation . My
intuition tells me
that i'm missing a lib or something but I can't put my
finger on it.
Please Help !
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