ref: def218a52a93259da43d7e2aa43e4a56a8cbd908
dir: /cc2/node.c/
/* See LICENSE file for copyright and license details. */ static char sccsid[] = "@(#) ./cc2/node.c"; #include <stdlib.h> #include <string.h> #include "../inc/scc.h" #include "cc2.h" #define NNODES 32 Node *curstmt; Symbol *curfun; struct arena { Node *mem; struct arena *next; }; static struct arena *arena; static Node *freep; Node * newnode(int op) { struct arena *ap; Node *np; if (!freep) { ap = xmalloc(sizeof(*ap)); ap->mem = xcalloc(NNODES, sizeof(Node)); ap->next = arena; arena = ap; for (np = ap->mem; np < &ap->mem[NNODES-1]; ++np) np->left = np+1; np->left = NULL; freep = np; } np = freep; freep = np->left; memset(np, 0, sizeof(*np)); np->op = op; return np; } #ifndef NDEBUG #include <stdio.h> static void prnode(Node *np) { if (np->left) prnode(np->left); if (np->right) prnode(np->right); fprintf(stderr, "\t%c%lu", np->op, np->type.size); } void prtree(Node *np) { prnode(np); putc('\n', stderr); } void prforest(char *msg) { Node *np; if (!curfun) return; fprintf(stderr, "%s {\n", msg); for (np = curfun->u.stmt; np; np = np->next) prtree(np); fputs("}\n", stderr); } #endif Node * addstmt(Node *np, int flag) { if (curstmt) np->next = curstmt->next; np->prev = curstmt; if (!curfun->u.stmt) curfun->u.stmt = np; else curstmt->next = np; if (flag == SETCUR) curstmt = np; return np; } Node * delstmt(void) { Node *next, *prev; next = curstmt->next; prev = curstmt->prev; if (next) next->prev = prev; if (prev) prev->next = next; else curfun->u.stmt = next; deltree(curstmt); return curstmt = next; } Node * nextstmt(void) { return curstmt = curstmt->next; } void delnode(Node *np) { np->left = freep; freep = np; } void deltree(Node *np) { if (!np) return; deltree(np->left); deltree(np->right); delnode(np); } void cleannodes(void) { struct arena *ap, *next; for (ap = arena; ap; ap = next) { next = ap->next; free(ap->mem); free(ap); } arena = NULL; freep = NULL; curstmt = NULL; } void apply(Node *(*fun)(Node *)) { if (!curfun) return; curstmt = curfun->u.stmt; while (curstmt) (*fun)(curstmt) ? nextstmt() : delstmt(); }