06-24-2002
Learn Unix, Eat Unix, Sleep Unix Etc. Mostly Experience much more on Unix everyday Makes me to become one.
9 More Discussions You Might Find Interesting
1. Programming
I have just installed C compiler, the installation
was successful but when I try to excute a gcc file I received the error message
"types.c: In function `main':
> types.c:4: warning: return type of `main' is not `int'
> ld: fatal: file values-Xa.o: open failed: No such file or directory
>... (5 Replies)
Discussion started by: hassan2
5 Replies
2. Programming
i'm using linux to compile my c program right now. are there any free c compiler with all the standard header file, such as <stdio.h>, <unistd.h>..., i can download and use?
can Microsoft Visual C++ compile C code?
thanks. (1 Reply)
Discussion started by: bb00y
1 Replies
3. Programming
I'm new to C but eager to get started. I purchasewd beginning C by Ivor Horton and realise that I need a C compiler. I looking for the most appropriate and economical way to obtain this, any suggestions would be greatly appreciated. (5 Replies)
Discussion started by: ferret
5 Replies
4. Programming
my C compiler cc is not working. probably it has corrupted.
can anyone tell me location from where i can download it.
Regards (4 Replies)
Discussion started by: rochitsharma
4 Replies
5. UNIX for Dummies Questions & Answers
Hi,
we are converting from IBM-AIX(xl c/c++ compiler) to Linux(GCC complier).
As a part of this i need to change the CFLAGS.
The xl c/c++ complier CFLAGS is
CFLAGS := $(CDEBUG) $(PROJECT_INCLUDE_DIRS) $(COBJECT_MODE) -qcpluscmt -qmakedep -qcheck=all \
-qalign=bit_packed $(LINT_FLAGS)... (0 Replies)
Discussion started by: pbattu1
0 Replies
6. Programming
To make a programming language you need a compiler, so what was the first programming language and how was is created if you need the compiler first?
The compiler itself is considered as a high language comparing to the machine! since the compiler is not created in 1's and 0's...
Eventhough i... (12 Replies)
Discussion started by: f.ben.isaac
12 Replies
7. Solaris
Greetings, :rolleyes: :o :confused:
I am working on Solaris 8. I have a few questions:
1. How do I determine if I have the CC compiler? I know it isn't in my $PATH, so how do I find it?
2. How do you install wget? I have read the INSTALL file, but I am not familar with the switches,... (25 Replies)
Discussion started by: Roam
25 Replies
8. UNIX for Dummies Questions & Answers
hi,
can we install gcc compiler in unix based OS(sun solar,IBM AIX,HP,etc) and also
can we install sun cc compiler in AIX environment and vice versa.
and more ..is linux support cc compiler
regards
Ajay (3 Replies)
Discussion started by: ajaysahoo
3 Replies
9. Shell Programming and Scripting
I have the code
.section .data
format_string: .asciz "Tong la '%d'\n"
n: .int 6
.section .text
.globl _start
_start:
movl $0,%esi
movl n,%eax
movl $0,%ecx
loop1:
cmp %eax,%ecx
je print
add %eax,%esi
dec %eax
jmp loop1
print:
movl $format_string, %edi
movl $0, %eax (1 Reply)
Discussion started by: toantk_55
1 Replies
LEARN ABOUT CENTOS
error::dwarf
ERROR::DWARF(7stap) ERROR::DWARF(7stap)
NAME
error::dwarf - dwarf debuginfo quality problems
DESCRIPTION
Systemtap sometimes relies on ELF/DWARF debuginfo for programs being instrumented to locate places to probe, or context variables to
read/write, just like a symbolic debugger does. Even though examination of the program's source code may show variables or lines where
probes may be desired, the compiler must preserve information about them for systemtap (or a debugger such as gdb) to get pinpoint access
to the desired information. If a script requires such data, but the compiler did not preserve enough of it, pass-2 errors may result.
Common conditions that trigger these problems include;
compiler version
Prior to GCC version 4.5, debuginfo quality was fairly limited. Often developers were advised to build their programs with -O0 -g
flags to disable optimization. GCC version 4.5 introduced a facility called "variable-tracking assignments" that allows it to gen-
erate high-quality debuginfo under full -O2 -g optimization. It is not perfect, but much better than before. Note that, due to
another gcc bug (PR51358) -O0 -g can actually sometimes make debuginfo quality worse than for -O2 -g.
function inlining
Even modern gcc sometimes has problems with parameters for inlined functions. It may be necessary to change the script to probe at
a slightly different place (try a .statement() probe, instead of a .function() probe, somewhere a few source lines into the body of
the inlined function. Or try putting a probe at the call site of the inlined function. Or use the if @defined($var) { ... } script
language construct to test for the resolvability of the context variable before using it.
instruction reordering
Heavily optimized code often smears the instructions from multiple source statements together. This can leave systemtap with no
place to choose to place a probe, especially a statement probe specified by line number. Systemtap may advise to try a nearby line
number, but these may not work well either. Consider placing a probe by a statement wildcard or line number range.
ALTERNATIVES
In order to reduce reliance on ELF/DWARF debuginfo, consider the use of statically compiled-in instrumentation, such as kernel tracepoints,
or <sys/sdt.h> userspace markers. Such instrumentation hook sites are relatively low cost (just one NOP instruction for sdt.h), and nearly
guarantee the availability of parameter data and a reliable probe site, all without reliance on debuginfo.
SEE ALSO
stap(1),
http://dwarfstd.org/,
http://sourceware.org/systemtap/wiki/TipContextVariables,
http://gcc.gnu.org/wiki/Var_Tracking_Assignments,
warning::debuginfo(7stap),
error::reporting(7stap)
ERROR::DWARF(7stap)