similar to: [LLVMdev] inspecting value of formal parameter in gdb for x86

I was told that my writeup lacked an example and details so I reproduced the code that X uses and I was able to boil down the issue to a couple of lines of code. Sorry again for the length of this email. Code was compiled on OpenBSD with clang 3.0-release. ======================================================================== With -O0 which works as X expects:

Sorry, this is the attachment. 2014-02-19 15:08 GMT+08:00 杨勇勇 <triple.yang at gmail.com>: > Thank you. > > Here is an example and the attchment contains extra files including object > file and executable file. > I want to print for example the value of "a", but lldb command "frame > variable a" displays "0" and so does "b", and

Hi everyone, I'm trying to get debug information for a C/pthreads application, but it seems like clang/LLVM are producing limited & erroneous debugging information. I've attached a simple test example to reproduce the problem -- I'm using clang/LLVM 3.7.1 built from source on Ubuntu 14.04. I compile the attached file with: $ clang -O1 -g test.c -lpthread If I run: $ readelf

Thank you, Clayton. This is very helpful. We use the LLDB specific GDB remote extensions, and our debugger server supports "qRegisterInfo" package. "reg 0x3c" is the frame pointer. In the example mentioned above, we have SP = FP - 40 for current call frame. And variable "a" is stored at address (FP + -24) from asm instruction [FP + -24] = R3;; Thus we can conclude

Hi David, Happy new year ! I just uploaded a POC patch that covers the cases when pointer points to un-named variables using DW_OP_implicit_pointer (references and dynamic allocation). This is using artificial variable as suggested by Paul. https://reviews.llvm.org/D72055 I hope that now it should address your concerns. Scope of DW_OP_implicit_pointer: As we initially decided split of

Problem seems not only with operator overloading, It occurs with struct value returning also. gdb while debugging expects the return value in eax, gcc does returns in eax, But Clang returns in edx(it can be checked in gdb by printing the contents of edx). Code(sample code) struct A1 { int x; int y; }; A1 sum(const A1 one, const A1 two) { A1 plus = {0,0}; plus.x = one.x + two.x; plus.y

Hi, As you told that function ends up returning void, I just confirmed it in the IR, the function is defined as: define *void* @_Z3sum2A1S_(*%struct.A1* noalias sret %agg.result*, %struct.A1* byval align 4 %one, %struct.A1* byval align 4 %two). But when i checked the register values in g++, eax contains an address of stack, which points to the value (object) returned by sum. That is if we

Hi, Structures are passed by pointer, so the return value is not actually in eax. That code gets transformed into something like: void sum(A1 *out, const A1 one, const A1 two) { out->x = one.x + two.x out->y = one.y + two.y } So actually the function ends up returning void and operating on a hidden parameter, so %eax is dead at the end of the function and should not be being relied

Hi Jim, Thanks for the advice. Since I'm using LLVM 2.9 style of debug information. Will this code benefit from those improvement or should I generate LLVM 3.0 style of debug information ? Best Regards Seb 2012/3/6 Jim Grosbach <grosbach at apple.com> > > On Mar 6, 2012, at 5:31 AM, Seb <babslachem at gmail.com> wrote: > > Hi all, > > Anyone have ideas/info on

> On Apr 27, 2018, at 7:48 AM, Son Tuan VU <sontuan.vu119 at gmail.com> wrote: > > Hi all, > > Consider this ARM assembly code of a C function: > > 00008124 <foo>: > 8124: push {r4, r6, r7, lr} > 8126: add r7, sp, #8 > 8128: mov r4, r0 > 812a: ldrsb.w

Hi all, Consider this ARM assembly code of a C function: 00008124 <foo>: 8124: push {r4, r6, r7, lr} 8126: add r7, sp, #8 8128: mov r4, r0 812a: ldrsb.w r0, [r2] 812e: cmp r0, #1 8130: itt lt 8132: movlt r0, #85 ;

Hi all, Anyone have ideas/info on this topic ? Thanks Seb 2012/3/2 Seb <babslachem at gmail.com> > Hi all, > > I'm using my own front-end to generate following code .ll file targeting > x86 32-bit: > > ; ModuleID = 'check.c' > target datalayout = >

On Mar 6, 2012, at 5:31 AM, Seb <babslachem at gmail.com> wrote: > Hi all, > > Anyone have ideas/info on this topic ? > Thanks > Seb > > 2012/3/2 Seb <babslachem at gmail.com> > Hi all, > > I'm using my own front-end to generate following code .ll file targeting x86 32-bit: > > ; ModuleID = 'check.c' > target datalayout =

Hi all, I'm using my own front-end to generate following code .ll file targeting x86 32-bit: ; ModuleID = 'check.c' target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32" target triple = "i386-pc-linux-gnu" @.str581 = internal constant [52 x i8] c"---- test number %d

All of this information is contained in the DWARF debug info that you must generate. Are you generating DWARF? If not, you will need to. If so, please attach an example program that contains DWARF and specify which function you are having trouble getting variable information for. Greg Clayton On Feb 18, 2014, at 12:44 AM, 杨勇勇 <triple.yang at gmail.com> wrote: > Hi, all > > I

For the given test: class A1 { int x; int y; public: A1(int a, int b) { x=a; y=b; } A1 operator+(const A1&); }; A1 A1::operator+(const A1& second) { A1 sum(0,0); sum.x = x + second.x; sum.y = y + second.y; return (sum); } int main (void) { A1 one(2,3); A1 two(4,5); return 0; } when the exectable of this code is debugged in gdb for i386, we dont get the

Thank you all for taking a look at this. I pasted the C source then deleted it because I was afraid that it was too long to read... Here's the code of *foo*. Its real name is *verifyPIN*. The variable *bar* is *userPin*. int *verifyPIN*(char **userPin*, char *cardPin, int *cpt) { int i; int status; int diff; if (*cpt > 0) { status = 0x55; diff = 0x55; for (i = 0; i

Hi, all I ported llvm backend and lldb recently. Both tools can basically work. lldb is able to debug programs in asm style and frame unwinding is OK. But "frame variable XX" does not work because lldb is not able to determine the address of XX from debug info. Can someone give any clue? Thanks in advance. -- 杨勇勇 (Yang Yong-Yong) -------------- next part -------------- An HTML

As Adrian said, we'd need to see the source of foo() to assess what the location-list for bar ought to be. Without actually going to look, I would guess that 'poplt' is considered a conditional move, therefore r4's contents are not guaranteed after it executes (i.e. it is a clobber). If one operand of 'poplt' is 'pc' then of course it is also a conditional indirect

On Fri, 2018-02-09 at 12:54 +0000, David Woodhouse wrote: > On Fri, 2018-02-09 at 10:36 +0000, David Woodhouse wrote: > >  > > Did you get anywhere with the function attribute? Having isolated the > > next boot failure to "it goes away if I compile io_apic.c without > > retpoline", bisecting it per-function would help to further delay the > > bit where I