how can I disable buffering on mtrace and output file with name from MALLOC_TRACE ??
the mtrace is started as:
$ cat libmtrace1.c
#include <mcheck.h>
static __attribute__((constructor)) void mtrace_install(void) {
atexit(&muntrace);
mtrace();
}
$gcc libmtrace1.c -fPIC -shared -o libmtrace1.so
$LD_PRELOAD=./libmtrace1.so MALLOC_TRACE=mtrace_log /bin/ls
Hey. Just write youself an another mtrace-like plugin and install it using malloc_hook(3).
Related
I am trying to follow and convert [this][1] Googletest tutorial to work in windows and use Make for building. I am also trying to add a more typical directory structure.
[1]: https://www.eriksmistad.no/getting-started-with-google-test-on-ubuntu/
My directory structure:
D:.
│ makefile
│
├───bin
├───inc
│ whattotest.h
│
├───obj
├───src
│ whattotest.cpp
│
└───tests
tests.cpp
whattotest.h
#pragma once
double squareRoot(const double a);
whattotest.cpp
#include <math.h>
#include "whattotest.h"
double squareRoot(const double a) {
double b = sqrt(a);
if(b != b) { // nan check
return -1.0;
}else{
return sqrt(a);
}
}
tests.cpp
#include "whattotest.h"
#include <gtest/gtest.h>
TEST(SquareRootTest, PositiveNos) {
ASSERT_EQ(6, squareRoot(36.0));
ASSERT_EQ(18.0, squareRoot(324.0));
ASSERT_EQ(25.4, squareRoot(645.16));
ASSERT_EQ(0, squareRoot(0.0));
}
TEST(SquareRootTest, NegativeNos) {
ASSERT_EQ(-1.0, squareRoot(-15.0));
ASSERT_EQ(-1.0, squareRoot(-0.2));
}
int main(int argc, char **argv) {
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
makefile
CXX = g++
OBJ = obj
SRC = src
TESTS = tests
INC = inc
BIN = bin
LIBS= -lpthread
GTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\googletest\include\
LIBGTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\lib\libgtest.a
.PHONY : all
all: $(BIN)/runTests
$(BIN)/runTests: $(OBJ)/tests.o $(OBJ)/whattotest.o $(LIBGTEST)
#g++ -o runTests obj/tests.o obj/whattotest.o <path to libgtest.a> -pthread
$(CXX) -o $# $^ $(LIBS)
$(OBJ)/tests.o: $(TESTS)/tests.cpp
#g++ -I <path to gtest> -I inc -c tests.cpp -o tests.o
$(CXX) -I $(GTEST) -I $(INC) -c $< -o $#
$(OBJ)/whattotest.o: $(SRC)/whattotest.cpp
$(CXX) -I $(INC) -c $< -o $#
clean:
-rm $(OBJ)/*.o
-rm $(BIN)/*.exe
When I run this I get the following error:
g++ -I D:\myWorkspace\Gtest\googletest-release-1.11.0\googletest\include LIBGTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\lib\libgtest.a -I inc -c tests/tests.cpp -o obj/tests.o
g++: warning: LIBGTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\lib\libgtest.a: linker input file unused because linking not done
g++: error: LIBGTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\lib\libgtest.a: linker input file not found: Invalid argument
make: *** [makefile:19: obj/tests.o] Error 1
The way I thought this would run would be for Make to see the Rule for runTests requires tests.o, which does not exist, then drop down and use the Rule for creating that object file. After that, return to the Rule for runTests and complete.
The output looks like Make is combining the two rules together into some kind of amalgamation with -c and .cpp files combined. Which I believe is causing this error to occur.
I am confused as to why Make is doing this.
Check this:
GTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\googletest\include\
LIBGTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\lib\libgtest.a
By having a backslash at the end of the GTEST variable assignment you've continued that line to the next line, so GTEST contains the variable assignment on the next line as well (and LIBGTEST is not set).
You've basically written this:
GTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\googletest\include LIBGTEST=D:\myWorkspace\Gtest\googletest-release-1.11.0\lib\libgtest.a
You should not, in general, use backslashes in makefiles. You should use forward slashes for directory separators.
If you do want to use backslashes at the least you should not add them at the end of variable assignments.
When compiling ltrace with icecc we run into a compilation problem. This is the minimal example:
main.c
#include <assert.h>
int main(int argc, char **argv) {
assert(argc != argc);
return 0;
}
test.sh:
#!/bin/bash
set -x
# one step compilation (no warning)
gcc -Wall main.c
# splitted compilation (warning)
gcc -Wall -E main.c -o main.i
gcc -Wall --preprocessed main.i
output:
++ gcc -Wall main.c
++ gcc -Wall -E main.c -o main.i
++ gcc -Wall --preprocessed main.i
main.c: In function ‘main’:
main.c:4:10: warning: self-comparison always evaluates to false [-Wtautological-compare]
assert(argc != argc);
^~
As you can see the result is different when compiling in one step and when preprocessing and compiling in two steps. Is this intended behavior?
I use gcc 6.3, the issue also appears in gcc 6.2 for ARM. I also cannot ignore this, as the full example uses -Werror.
Im using gcc on Linux and creating a shared library for static libraries. I dont want symbols from some static libraries to be exported.
gcc version is 4.8.0.
Im trying this option at gcc command and it's not working:
-Wl,--exclude-libs,libabc.a .
If I use this option, it's removing all the symbols which not what I want.:
-Wl,--exclude-libs,ALL
Can somebody help in how to use --exclude-option and not to export symbols from specific static library, please?
Thanks
Chandra
Please ignore my comment to question, it is incorrect.
Minimal example:
test1.c:
int testvar1;
int test1(void) {
return 1;
}
test2.c:
extern int testvar1;
int test1(void);
int test2(void) {
testvar1 = -1;
return test1() + 2;
}
test.c:
#include <stdio.h>
#include <dlfcn.h>
int main(int argc, char **argv) {
void *lib = dlopen("./libtest2.so", RTLD_NOW);
int (*f)(void) = dlsym(lib, "test2");
printf("%d\n", f());
return 0;
}
Build:
$ gcc -fPIC -c test1.c
$ ar cru libtest1.a test1.o
$ gcc -fPIC -c test2.c
$ gcc -shared -o libtest2.so test2.o -L. -ltest1 -Wl,--exclude-libs,libtest1.a
$ gcc test.c -ldl
$ ./a.out
3
$ readelf --syms -D libtest2.so | grep test1
$
I'm playing around with XPC, GCD and go but I hit a quick wall when my code was failing to compile with the following error messages (which I don't understand):
main(__DATA/__const): unexpected reloc for dynamic symbol _NSConcreteGlobalBlock
main(__DATA/__const): unhandled relocation for _NSConcreteGlobalBlock (type 28 rtype 120)
I am compiling using go build the code that follows:
main.go
package main
/*
#include <xpc/xpc.h>
#include "wrapper.h"
*/
import "C"
import (
"fmt"
)
//export HandleXPCEvent
func HandleXPCEvent(event C.xpc_object_t) {
fmt.Println("Event was handled")
}
func main() {
name := C.CString("com.example.xpc")
queue := C.dispatch_queue_create(name, nil)
conn := C.xpc_connection_create(name, queue)
C.set_event_handler(conn)
//C.xpc_connection_resume(conn)
}
wrapper.h
#ifndef _WRAPPER_H_
#define _WRAPPER_H_
#include <stdlib.h>
#include <stdio.h>
#include <xpc/xpc.h>
xpc_connection_t connect( char* name);
void set_event_handler(xpc_connection_t connection);
#endif
wrapper.c
#include "wrapper.h"
#include <dispatch/dispatch.h>
extern void HandleXPCEvent(xpc_object_t);
xpc_connection_t connect( char* name) {
dispatch_queue_t queue = dispatch_queue_create(name,0);
return xpc_connection_create(name,queue);
}
void set_event_handler(xpc_connection_t connection) {
xpc_connection_set_event_handler(connection, ^(xpc_object_t event) {
xpc_retain(event);
// Call Go function
HandleXPCEvent(event);
});
}
I'm I doing something wrong? Is this some kind of go bug or how can this be fixed?
Update:
I ran go build -x -work on my project and I got the following output:
➣ go build -x -work
WORK=/var/folders/fb/bgfqk8wx5x16w7yh2cg50vrw0000gn/T/go-build524335717
mkdir -p $WORK/github.com/gabrielayuso/go-xpc/_obj/
mkdir -p $WORK/github.com/gabrielayuso/go-xpc/_obj/exe/
cd /Users/gabrielayuso/Documents/Workspace/Projects/go/src/github.com/gabrielayuso/go-xpc
/usr/local/go/pkg/tool/darwin_amd64/cgo -objdir $WORK/github.com/gabrielayuso/go-xpc/_obj/ -- -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ main.go
/usr/local/go/pkg/tool/darwin_amd64/6c -F -V -w -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ -I /usr/local/go/pkg/darwin_amd64 -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_defun.6 -D GOOS_darwin -D GOARCH_amd64 $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_defun.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -print-libgcc-file-name
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_main.o -c $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_main.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_export.o -c $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_export.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ -o $WORK/github.com/gabrielayuso/go-xpc/_obj/main.cgo2.o -c $WORK/github.com/gabrielayuso/go-xpc/_obj/main.cgo2.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ -o $WORK/github.com/gabrielayuso/go-xpc/_obj/wrapper.o -c ./wrapper.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_.o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_main.o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_export.o $WORK/github.com/gabrielayuso/go-xpc/_obj/main.cgo2.o $WORK/github.com/gabrielayuso/go-xpc/_obj/wrapper.o
/usr/local/go/pkg/tool/darwin_amd64/cgo -objdir $WORK/github.com/gabrielayuso/go-xpc/_obj/ -dynimport $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_.o -dynout $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_import.c
/usr/local/go/pkg/tool/darwin_amd64/6c -F -V -w -I $WORK/github.com/gabrielayuso/go-xpc/_obj/ -I /usr/local/go/pkg/darwin_amd64 -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_import.6 -D GOOS_darwin -D GOARCH_amd64 $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_import.c
gcc -I . -g -O2 -fPIC -m64 -pthread -fno-common -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_all.o $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_export.o $WORK/github.com/gabrielayuso/go-xpc/_obj/main.cgo2.o $WORK/github.com/gabrielayuso/go-xpc/_obj/wrapper.o -Wl,-r -nostdlib /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/x86_64/libgcc.a
/usr/local/go/pkg/tool/darwin_amd64/6g -o $WORK/github.com/gabrielayuso/go-xpc/_obj/_go_.6 -p github.com/gabrielayuso/go-xpc -D _/Users/gabrielayuso/Documents/Workspace/Projects/go/src/github.com/gabrielayuso/go-xpc -I $WORK $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_gotypes.go $WORK/github.com/gabrielayuso/go-xpc/_obj/main.cgo1.go
/usr/local/go/pkg/tool/darwin_amd64/pack grcP $WORK $WORK/github.com/gabrielayuso/go-xpc.a $WORK/github.com/gabrielayuso/go-xpc/_obj/_go_.6 $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_import.6 $WORK/github.com/gabrielayuso/go-xpc/_obj/_cgo_defun.6 $WORK/github.com/gabrielayuso/go-xpc/_obj/_all.o
cd .
/usr/local/go/pkg/tool/darwin_amd64/6l -o $WORK/github.com/gabrielayuso/go-xpc/_obj/exe/a.out -L $WORK $WORK/github.com/gabrielayuso/go-xpc.a
# github.com/gabrielayuso/go-xpc
main(__DATA/__const): unexpected reloc for dynamic symbol _NSConcreteGlobalBlock
main(__DATA/__const): unhandled relocation for _NSConcreteGlobalBlock (type 28 rtype 120)
Content of $WORK dir as generated by go build -x -work: go-xpc_work.zip
I'm not very familiar with compiling and linking therefore I can't make much sense of this output. I just noticed that _cgo_import.c a file generated by cgo (with options -dynimport and -dynout) has #pragma cgo_import_dynamic _NSConcreteGlobalBlock _NSConcreteGlobalBlock "" in the first line which is related to the error message the linker gave.
Hope this information can help to find out what the problem is and how to solve it.
I don't know much about those libraries but nothing jumps out at me with the code you have here.
Some useful debug output can be obtained from go build -x -work which will print the commands and the working directory for you.
The working directory will be left untouched so you can go look at the code cgo generates for you. That plus the commands it will print for you should get you started on tracking down the problem.
I have a wrapper written up for using Go and XPC in Cocoa Applications.
It's located here:
https://github.com/aventurella/go-xpc
I am trying to link a static library while creating my program executable using the below makefile..
IDIR =../inc
CC=g++ -g
CFLAGS=-I$(IDIR)
WFLAGS=-Wall -W
OFLAGS=-O3
DLINUX=-D_LINUX
ODIR=obj
LDIR =../lib
LIBS=-lm
_OBJ = testclient.o
OBJ = $(patsubst %,$(ODIR)/%,$(_OBJ))
$(ODIR)/testclient.o: testclient.c
$(CC) -c $< $(CFLAGS) -o $#
$(ODIR)/file2.o: file2.c
$(CC) -c $< $(CFLAGS) -o $#
testclient: $(OBJ)
$(CC) -o $# $^ $(LIBS) -lccn -pthread
.PHONY: clean
clean:
rm -f $(ODIR)/*.o *~ core $(INCDIR)/*~
I have tried everything available from changing the order of the '-lccn' parameter to checking whether the function exists in the library (nm libccn.a gives the required function ccn_create() in it). The error returned is :
obj/testclient.o: In function `main':
/root/testClient/src/testclient.c:91: undefined reference to `ccn_create()'
The library libccn.a is in /usr/local/lib. I have also tried changing the directory path and then using -L flag to look in that location. Doesn't work either. :( ..Any ideas as to how can i make it work ?
My guess is that libccn.a is a C library and the header that you use are not designed to be imported by a C++ compiler (there is no extern "C" { } block surrounding the function definition).
C++ supports function overloading by mangling name of function. When you put a function in a extern "C" { } block, C++ disable name mangling (and thus disable overloading). Here, in your error message, the function mentioned is ccn_create(). Notice the (), this means that the function type is known, and thus the named looked up was a mangled name.
When you do nm libccn.a you see the real name, and it is ccn_create. That is not a mangled name. So to fix this, you'll need to surround the function definition in a export "C" { } block. The easiest way to do that is to surround the #include in such a block.
BTW, you can reproduce the error by doing this.
$ echo 'void ccn_create();' > ccn.h
$ echo '#include "ccn.h"
void ccn_create() { }' > ccn.c
$ echo '#include "ccn.h"
int main () {
ccn_create();
return 0;
}' > main.cc
$ gcc -o ccn.o -c ccn.c
$ g++ -o main main.cc ccn.o
Undefined symbols for architecture x86_64:
"ccn_create()", referenced from:
_main in cc8XnYRq.o
ld: symbol(s) not found for architecture x86_64
$ echo 'extern "C" {
#include "ccn.h"
}
int main () {
ccn_create();
return 0;
}' > main.cc
$ g++ -o main main.cc ccn.o