common.cc

#include <execinfo.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

#include "common.h"
#include "model.h"
#include "execution.h"
#include "stacktrace.h"
#include "output.h"
#include "utils.h"

#define MAX_TRACE_LEN 100

/** @brief Model-checker output file descriptor; default to stdout until redirected */
int model_out = STDOUT_FILENO;

// #define CONFIG_STACKTRACE
// #define DETAILED_STACKTRACE

#ifdef DETAILED_STACKTRACE
static void run_cmd(char * cmd, char *result) {
	FILE *fp = popen(cmd, "r");
	char output [1024];
	if (fp == NULL) {
		printf("Failed to run command\n" );
		exit(1);
	}

	/* Read the output a line at a time - output it. */
	while (fgets(output, sizeof(output), fp) != NULL) {
		replace_char(output, '\n', ':');
		strcat(result, output);
	}
	/* close */
	pclose(fp);
}
#endif

/** Print a backtrace of the current program state. */
void print_trace(void)
{
#ifdef CONFIG_STACKTRACE
	print_stacktrace(model_out);
#else
	void *array[MAX_TRACE_LEN];
	char **strings;
	int size, i;

	size = backtrace(array, MAX_TRACE_LEN);
	strings = backtrace_symbols(array, size);

	model_print("\nDumping stack trace (%d frames):\n", size);

	for (i = 0;i < size;i++) {
#ifdef DETAILED_STACKTRACE
		char *sharedlib = strtok(strings[i], "(");
		char *func = strtok(NULL, "+");
		char *offset = strtok(NULL, ")");
		char cmd[2048] = {0};
		if(offset) {
			sprintf(cmd,"funcaddr=$(nm %s | grep %s | head -n1 | cut -d \" \" -f1) && funcoffset=$(python -c \"print hex(0x${funcaddr}+%s)\") && addr2line -e %s ${funcoffset}",
				sharedlib, func, offset, sharedlib);
		} else {
			offset = strtok(func, ")");
			sprintf(cmd,"addr2line -a -f --exe=%s %s", sharedlib, offset);
		}
		char output[1024] ={0};
		run_cmd(cmd, output);
		model_print("\t%s:%s(%s)\n", sharedlib, func, output);
#else 
		model_print("\t%s\n", strings[i]);
#endif
	}
	free(strings);
#endif	/* CONFIG_STACKTRACE */
}

void assert_hook(void)
{
	model->get_execution()->print_summary(true, true);
	model_print("Add breakpoint to line %u in file %s.\n", __LINE__, __FILE__);
}

void model_assert(bool expr, const char *file, int line)
{
	if (!expr) {
		char msg[100];
		sprintf(msg, "Program has hit assertion in file %s at line %d\n",
						file, line);
		model->assert_user_bug(msg);
	}
}

#ifndef CONFIG_DEBUG

static int fd_user_out;	/**< @brief File descriptor from which to read user program output */

/**
 * @brief Setup output redirecting
 *
 * Redirects user program's stdout to a pipe so that we can dump it
 * selectively, when displaying bugs, etc.
 * Also connects a file descriptor 'model_out' directly to stdout, for printing
 * data when needed.
 *
 * The model-checker can selectively choose to print/hide the user program
 * output.
 * @see clear_program_output
 * @see print_program_output
 *
 * Note that the user program's pipe has limited memory, so if a program will
 * output much data, we will need to buffer it in user-space during execution.
 * This also means that if ModelChecker decides not to print an execution, it
 * should promptly clear the pipe.
 *
 * This function should only be called once.
 */
char filename[256];

void redirect_output()
{
	/* Save stdout for later use */
	model_out = dup(STDOUT_FILENO);
	if (model_out < 0) {
		perror("Error in dup\n");
		exit(EXIT_FAILURE);
	}
	snprintf_(filename, sizeof(filename), "PMCheckOutput%d", getpid());
	fd_user_out = open(filename, O_CREAT | O_TRUNC| O_RDWR, S_IRWXU);
	if (dup2(fd_user_out, STDOUT_FILENO) < 0) {
		perror("Error in dup2");
		exit(EXIT_FAILURE);
	}

}

/**
 * @brief Wrapper for reading data to buffer
 *
 * Besides a simple read, this handles the subtleties of EOF and nonblocking
 * input (if fd is O_NONBLOCK).
 *
 * @param fd The file descriptor to read.
 * @param buf Buffer to read to.
 * @param maxlen Maximum data to read to buffer
 * @return The length of data read. If zero, then we hit EOF or ran out of data
 * (non-blocking)
 */
static ssize_t read_to_buf(int fd, char *buf, size_t maxlen)
{
	ssize_t ret = read(fd, buf, maxlen);
	if (ret < 0) {
		if (errno == EAGAIN || errno == EWOULDBLOCK) {
			return 0;
		} else {
			perror("read");
			exit(EXIT_FAILURE);
		}
	}
	return ret;
}

/** @brief Dump any pending program output without printing */
void clear_program_output()
{
	fflush(stdout);
	close(fd_user_out);
	unlink(filename);
}

/** @brief Print out any pending program output */
void print_program_output()
{
	char buf[200];

	model_print("---- BEGIN PROGRAM OUTPUT ----\n");

	/* Gather all program output */
	fflush(stdout);

	lseek(fd_user_out, 0, SEEK_SET);
	/* Read program output pipe and write to (real) stdout */
	ssize_t ret;
	while (1) {
		ret = read_to_buf(fd_user_out, buf, sizeof(buf));
		if (!ret)
			break;
		while (ret > 0) {
			ssize_t res = write(model_out, buf, ret);
			if (res < 0) {
				perror("write");
				exit(EXIT_FAILURE);
			}
			ret -= res;
		}
	}

	close(fd_user_out);
	unlink(filename);

	model_print("---- END PROGRAM OUTPUT   ----\n");
}
#endif	/* ! CONFIG_DEBUG */