[gccsdk] [Bug 236] New: GCC 4.1.2 Rel 2 Dev 2012-05-01: fork/execvp/dup2 redirection problem

http://www.riscos.info/bugzilla3/show_bug.cgi?id=236

Summary: GCC 4.1.2 Rel 2 Dev 2012-05-01: fork/execvp/dup2
redirection problem
Product: GCC/GCCSDK
Version: other
Platform: Other
OS/Version: RISC OS
Status: NEW
Severity: normal
Priority: P1
Component: C compiler
AssignedTo: John.Tytgat@aaug.net
ReportedBy: duncan_moore@ntlworld.com
Estimated Hours: 0.0


GCCSDK GCC 4.1.2 Release 2 Development 2012-05-01
SharedUnixLibrary 1.12
VRPC RISC OS 4.39

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h> // open
#include <unistd.h> // close
#include <sys/wait.h> // wait WEXITSTATUS

//---------------------------------------------------------------------------
static int redirect(char* const cmd[],int file_in,int file_out,int file_err) {
pid_t childpid; // Child's pid.
int retval; // Child process return code.
int status; // Parent process return code.

childpid=fork(); // Create new process.
if (childpid==0) { // Child process.
if (file_in >=0) dup2(file_in, STDIN_FILENO); // Redirect standard input
if (file_out>=0) dup2(file_out,STDOUT_FILENO); // Redirect standard output
if (file_err>=0) dup2(file_err,STDERR_FILENO); // Redirect standard error
retval=execvp(cmd[0],cmd); // execvp() does not return on success, only on
failure.
return retval;
}
else if (childpid>0) { // Parent process.
wait(&status); // Wait for child to exit, and store its status.
return WEXITSTATUS(status);
} else { // fork() returns -1 on failure.
fprintf(stderr,"fork() error\n");
exit(1);
}
}
//---------------------------------------------------------------------------
int main(void) {
int file_in =open("file_in",O_RDONLY);
int file_out=open("file_out",O_WRONLY|O_CREAT);
int file_err=open("file_err",O_WRONLY|O_CREAT);
printf("%i %i %i\n",file_in,file_out,file_err);

printf("1\n");

char* cmd[]={"gcc","-dumpmachine",0};
if (redirect(cmd,file_in,file_out,file_err)!=0) printf("system error\n");

close(file_in);
close(file_out);
close(file_err);

printf("2\n");

return 0;
}

This is what I think we should get:

*test
-1 3 4
1
2
*Type file_err
*Type file_out
arm-unknown-riscos
*

What I get is, file_err and file_out are correct, but

*test
-1 3 4
1

Error 0xe59ff400:
pc: 0001fffc

Fatal signal received: EMT trap

Stack backtrace:

Running thread 0x2ee3c
( 807f7c) pc: 22050 lr: 225d0 sp: 807f80 __write_backtrace()
( 807fe4) pc: 22174 lr: 22c74 sp: 807fe8 __unixlib_raise_signal()
( 807ff4) pc: 22bac lr: 15eec sp: 806f20 UnixLibErrorHandler()
( 806f48) pc: 15e68 lr: 190b0 sp: 806f4c __ttywrite()
( 806f6c) pc: 18fcc lr: 23d6c sp: 806f70 write()
( 806f88) pc: 23c98 lr: 243a8 sp: 806f8c __flsbuf()
( 806fa4) pc: 242f8 lr: 8908 sp: 806fa8 fputc()
( 806fbc) pc: 88d0 lr: 831c sp: 806fc0 puts()
( 806fec) pc: 8240 lr: 11078 sp: 806ff0 main()

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