code / tomo

   1 // This file defines some code to print stack traces.
   2 
   3 #ifndef _GNU_SOURCE
   4 #define _GNU_SOURCE
   5 #endif
   6 
   7 #include <dlfcn.h>
   8 #include <err.h>
   9 #include <execinfo.h>
  10 #include <gc.h>
  11 #include <limits.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <unistd.h>
  16 
  17 #include "../config.h"
  18 #include "print.h"
  19 #include "simpleparse.h"
  20 #include "util.h"
  21 
  22 extern bool USE_COLOR;
  23 
  24 static void fprint_context(FILE *out, const char *filename, int lineno, int context_before, int context_after) {
  25     FILE *f = fopen(filename, "r");
  26     if (!f) return;
  27     char *line = NULL;
  28     size_t size = 0;
  29     ssize_t nread;
  30     int64_t cur_line = 1;
  31 
  32     int num_width = 1;
  33     for (int n = lineno + context_after; n >= 10; n /= 10)
  34         num_width += 1;
  35 
  36     while ((nread = getline(&line, &size, f)) != -1) {
  37         if (line[nread - 1] == '\n') line[nread - 1] = '\0';
  38 
  39         if (cur_line >= lineno - context_before) {
  40             int w = 1;
  41             for (int n = cur_line; n >= 10; n /= 10)
  42                 w += 1;
  43 
  44             if (USE_COLOR) {
  45                 fprint(out, cur_line == lineno ? "\033[31;1m>\033[m " : "  ", "\033[2m",
  46                        repeated_char(' ', num_width - w), cur_line, "\033(0\x78\033(B",
  47                        cur_line == lineno ? "\033[0;31;1m" : "\033[0m", line, "\033[m");
  48             } else {
  49                 fprint(out, cur_line == lineno ? "> " : "  ", repeated_char(' ', num_width - w), cur_line, "| ", line);
  50             }
  51         }
  52 
  53         cur_line += 1;
  54         if (cur_line > lineno + context_after) break;
  55     }
  56     if (line) free(line);
  57     fclose(f);
  58 }
  59 
  60 static void _print_stack_frame(FILE *out, const char *cwd, const char *install_dir, const char *function,
  61                                const char *filename, int lineno) {
  62     if (function == NULL) {
  63         fprint(out, USE_COLOR ? "\033[2m...unknown function...\033[m" : "...unknown function...");
  64         return;
  65     }
  66 
  67     function = String(string_slice(function, strcspn(function, "+")));
  68     if (function[0] == '\0') function = "???";
  69 
  70     char *function_display = GC_MALLOC_ATOMIC(strlen(function));
  71     memcpy(function_display, function, strlen(function) + 1);
  72     char *last_dollar = strrchr(function_display, '$');
  73     if (last_dollar) *last_dollar = '\0';
  74     for (char *p = function_display; *p; p++) {
  75         if (*p == '$') *p = '.';
  76     }
  77 
  78     if (filename) {
  79         if (strncmp(filename, cwd, strlen(cwd)) == 0) filename += strlen(cwd);
  80 
  81         fprint_inline(out, USE_COLOR ? "\033[1mIn \033[33m" : "In ", function_display, USE_COLOR ? "()\033[37m" : "()");
  82         if (install_dir[0] && strncmp(filename, install_dir, strlen(install_dir)) == 0)
  83             fprint_inline(out, USE_COLOR ? " in package \033[35m" : " in package ", filename, ":", lineno);
  84         else fprint(out, USE_COLOR ? " in \033[35m" : " in ", filename, ":", lineno);
  85         fprint(out, USE_COLOR ? "\033[m" : "");
  86         fprint_context(out, filename, lineno, 3, 1);
  87     } else {
  88         fprint(out, "LINE: ", function);
  89     }
  90 }
  91 
  92 __attribute__((noinline)) public
  93 void print_stacktrace(FILE *out, int offset) {
  94     char cwd[PATH_MAX];
  95     if (getcwd(cwd, sizeof(cwd)) == NULL) errx(1, "Path too large!");
  96     size_t cwd_len = strlen(cwd);
  97     if (cwd_len + 2 > sizeof(cwd)) errx(1, "Path too large!");
  98     cwd[cwd_len++] = '/';
  99     cwd[cwd_len] = '\0';
 100 
 101     const char *install_dir = String(TOMO_PATH, "/lib/tomo@", TOMO_VERSION, "/");
 102 
 103     static void *stack[1024];
 104     int64_t size = (int64_t)backtrace(stack, sizeof(stack) / sizeof(stack[0]));
 105     char **strings = backtrace_symbols(stack, size);
 106     bool main_func_onwards = false;
 107     for (int64_t i = size - 1; i > offset; i--) {
 108         Dl_info info;
 109         void *call_address = stack[i] - 1;
 110         if (dladdr(call_address, &info) && info.dli_fname) {
 111             const char *file = info.dli_fname;
 112             uintptr_t frame_offset = (uintptr_t)call_address - (uintptr_t)info.dli_fbase;
 113             FILE *fp = popen(String("addr2line -f -e '", file, "' ", (void *)frame_offset, " 2>/dev/null"), "r");
 114             if (fp) {
 115                 const char *function = NULL, *filename = NULL;
 116                 long line_num = 0;
 117                 if (fparse(fp, &function, "\n", &filename, ":", &line_num) == NULL) {
 118                     if (starts_with(function, "main$")) main_func_onwards = true;
 119                     if (main_func_onwards) _print_stack_frame(out, cwd, install_dir, function, filename, line_num);
 120                 } else {
 121                     if (main_func_onwards) _print_stack_frame(out, cwd, install_dir, NULL, NULL, line_num);
 122                 }
 123                 pclose(fp);
 124             }
 125         } else {
 126             if (main_func_onwards) _print_stack_frame(out, cwd, install_dir, NULL, NULL, 0);
 127         }
 128         if (main_func_onwards && i - 1 > offset) fputs("\n", out);
 129     }
 130     free(strings);
 131 }