A dynamic tracer for Linux

node.c 3.1KB

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  1. #include <assert.h>
  2. #include <ctype.h>
  3. #include <errno.h>
  4. #include <inttypes.h>
  5. #include <search.h>
  6. #include <stdarg.h>
  7. #include <stdio.h>
  8. #include <stdlib.h>
  9. #include <string.h>
  10. #include "node.h"
  11. #include "printxf.h"
  12. void node_print(struct node *n, FILE *fp)
  13. {
  14. switch (n->ntype) {
  15. case N_EXPR:
  16. fprintf(fp, "\e[31m%s\e[0m", n->expr.func);
  17. break;
  18. case N_IDENT:
  19. fputs(n->ident.name, fp);
  20. break;
  21. case N_NUM:
  22. if (n->num.unsignd)
  23. fprintf(fp, "%"PRIu64, n->num.u64);
  24. else
  25. fprintf(fp, "%"PRId64, n->num.s64);
  26. break;
  27. case N_STRING:
  28. fprintf(fp, "\"%s\"", n->string.data);
  29. break;
  30. default:
  31. fputs("<INVALID>", fp);
  32. }
  33. }
  34. int node_vfprintxf(struct printxf *pxf, FILE *fp, const char *spec, va_list ap)
  35. {
  36. struct node *n;
  37. n = va_arg(ap, struct node *);
  38. /* TODO: "%#N" should print source file location */
  39. node_print(n, fp);
  40. return 0;
  41. }
  42. int node_walk(struct node *n,
  43. int (*pre)(struct node *, void *),
  44. int (*post)(struct node *, void *),
  45. void *ctx)
  46. {
  47. int err = 0;
  48. if (pre && (err = pre(n, ctx)))
  49. return err;
  50. if (n->ntype == N_EXPR) {
  51. struct node *arg;
  52. node_expr_foreach(n, arg) {
  53. err = node_walk(arg, pre, post, ctx);
  54. if (err)
  55. return err;
  56. }
  57. }
  58. if (post && (err = post(n, ctx)))
  59. return err;
  60. return 0;
  61. }
  62. int node_replace(struct node *n, struct node *new)
  63. {
  64. new->up = n->up;
  65. if (n->prev) {
  66. new->prev = n->prev;
  67. n->prev->next = new;
  68. }
  69. if (n->next) {
  70. new->next = n->next;
  71. n->next->prev = new;
  72. }
  73. /* TODO: don't leak memory */
  74. return 0;
  75. }
  76. /* helpers */
  77. int node_is_block(struct node *n)
  78. {
  79. if (!n || (n->ntype != N_EXPR))
  80. return 0;
  81. return !strcmp(n->expr.func, ":block");
  82. }
  83. int node_is_map(struct node *n)
  84. {
  85. if (!n || (n->ntype != N_EXPR))
  86. return 0;
  87. return !strcmp(n->expr.func, "{}");
  88. }
  89. /* constructors */
  90. static struct node *node_new(enum ntype ntype)
  91. {
  92. struct node *n;
  93. n = calloc(1, sizeof(*n));
  94. assert(n);
  95. n->ntype = ntype;
  96. return n;
  97. }
  98. struct node *node_string(char *data)
  99. {
  100. struct node *n = node_new(N_STRING);
  101. n->string.data = data;
  102. return n;
  103. }
  104. struct node *node_num(const char *numstr)
  105. {
  106. struct node *n = node_new(N_NUM);
  107. if (numstr[0] == '-')
  108. numstr++;
  109. else
  110. n->num.unsignd = 1;
  111. errno = 0;
  112. n->num.u64 = strtoull(numstr, NULL, 0);
  113. if (!errno) {
  114. if (!n->num.unsignd)
  115. n->num.s64 = -n->num.u64;
  116. return n;
  117. }
  118. assert(0);
  119. return NULL;
  120. }
  121. struct node *node_ident(char *name)
  122. {
  123. struct node *n = node_new(N_IDENT);
  124. n->ident.name = name;
  125. return n;
  126. }
  127. struct node *node_append(struct node *n, struct node *arg)
  128. {
  129. struct node *last;
  130. assert(n->ntype == N_EXPR);
  131. arg->up = n;
  132. if (!n->expr.args) {
  133. n->expr.args = arg;
  134. return n;
  135. }
  136. for (last = n->expr.args; last->next; last = last->next);
  137. last->next = arg;
  138. arg->prev = last;
  139. return n;
  140. }
  141. struct node *node_expr(char *func, ...)
  142. {
  143. va_list ap;
  144. struct node *n, *arg;
  145. n = node_new(N_EXPR);
  146. n->expr.func = func;
  147. va_start(ap, func);
  148. while ((arg = va_arg(ap, struct node *)))
  149. node_append(n, arg);
  150. va_end(ap);
  151. return n;
  152. }
  153. __attribute__((constructor))
  154. static void node_init(void)
  155. {
  156. printxf_default.vfprintxf['N'] = node_vfprintxf;
  157. }