-/* $OpenBSD: make.c,v 1.71 2016/10/21 16:12:38 espie Exp $ */
+/* $OpenBSD: make.c,v 1.72 2017/06/22 17:08:20 espie Exp $ */
/* $NetBSD: make.c,v 1.10 1996/11/06 17:59:15 christos Exp $ */
/*
static void MakeAddChild(void *, void *);
static void MakeHandleUse(void *, void *);
static bool MakeStartJobs(void);
-static void MakePrintStatus(void *, void *);
+static void MakePrintStatus(void *);
+
+/* Cycle detection functions */
+static bool targets_contain_cycles(void);
+static void print_unlink_cycle(struct growableArray *, GNode *);
+static void break_and_print_cycles(Lst);
+static GNode *find_cycle(Lst, struct growableArray *);
+
static bool try_to_make_node(GNode *);
static void add_targets_to_make(Lst);
return false;
}
-/*-
- *-----------------------------------------------------------------------
- * MakePrintStatus --
- * Print the status of a top-level node, viz. it being up-to-date
- * already or not created due to an error in a lower level.
- * Callback function for Make_Run via Lst_ForEach.
- *
- * Side Effects:
- * A message may be printed.
- *-----------------------------------------------------------------------
- */
static void
-MakePrintStatus(
- void *gnp, /* Node to examine */
- void *cyclep) /* True if gn->unmade being non-zero implies
- * a cycle in the graph, not an error in an
- * inferior */
+MakePrintStatus(void *gnp)
{
GNode *gn = gnp;
- bool *cp = cyclep;
- bool cycle = *cp;
if (gn->built_status == UPTODATE) {
printf("`%s' is up to date.\n", gn->name);
} else if (gn->unmade != 0) {
- if (cycle) {
- bool t = true;
- /*
- * If printing cycles and came to one that has unmade
- * children, print out the cycle by recursing on its
- * children. Note a cycle like:
- * a : b
- * b : c
- * c : b
- * will cause this to erroneously complain about a
- * being in the cycle, but this is a good approximation.
- */
- if (gn->built_status == CYCLE) {
- Error("Graph cycles through `%s'", gn->name);
- gn->built_status = ENDCYCLE;
- Lst_ForEach(&gn->children, MakePrintStatus, &t);
- gn->built_status = UNKNOWN;
- } else if (gn->built_status != ENDCYCLE) {
- gn->built_status = CYCLE;
- Lst_ForEach(&gn->children, MakePrintStatus, &t);
- }
- } else {
- printf("`%s' not remade because of errors.\n",
- gn->name);
- }
+ printf("`%s' not remade because of errors.\n", gn->name);
}
}
-
static void
MakeAddChild(void *to_addp, void *ap)
{
Make_Run(Lst targs) /* the initial list of targets */
{
bool problem; /* errors occurred */
- GNode *gn;
- unsigned int i;
- bool cycle;
/* wild guess at initial sizes */
Array_Init(&toBeMade, 500);
}
problem = Job_Finish();
- cycle = false;
- for (gn = ohash_first(&targets, &i); gn != NULL;
- gn = ohash_next(&targets, &i)) {
- if (has_been_built(gn))
- continue;
- cycle = true;
- problem = true;
- printf("Error: target %s unaccounted for (%s)\n",
- gn->name, status_to_string(gn));
- }
/*
* Print the final status of each target. E.g. if it wasn't made
* because some inferior reported an error.
*/
- Lst_ForEach(targs, MakePrintStatus, &cycle);
+ if (targets_contain_cycles()) {
+ break_and_print_cycles(targs);
+ problem = true;
+ }
+ Lst_Every(targs, MakePrintStatus);
if (problem)
Fatal("Errors while building");
return true;
}
+
+/* round-about detection: assume make is bug-free, if there are targets
+ * that have not been touched, it means they never were reached, so we can
+ * look for a cycle
+ */
+static bool
+targets_contain_cycles(void)
+{
+ GNode *gn;
+ unsigned int i;
+ bool cycle = false;
+ bool first = true;
+
+ for (gn = ohash_first(&targets, &i); gn != NULL;
+ gn = ohash_next(&targets, &i)) {
+ if (has_been_built(gn))
+ continue;
+ cycle = true;
+ if (first)
+ printf("Error target(s) unaccounted for: ");
+ printf("%s ", gn->name);
+ first = false;
+ }
+ if (!first)
+ printf("\n");
+ return cycle;
+}
+
+static void
+print_unlink_cycle(struct growableArray *l, GNode *c)
+{
+ LstNode ln;
+ GNode *gn = NULL;
+ unsigned int i;
+
+ printf("Cycle found: ");
+
+ for (i = 0; i != l->n; i++) {
+ gn = l->a[i];
+ if (gn == c)
+ printf("(");
+ printf("%s -> ", gn->name);
+ }
+ printf("%s)\n", c->name);
+ assert(gn);
+
+ /* So the first element is tied to our node, find and kill the link */
+ for (ln = Lst_First(&gn->children); ln != NULL; ln = Lst_Adv(ln)) {
+ GNode *gn2 = Lst_Datum(ln);
+ if (gn2 == c) {
+ Lst_Remove(&gn->children, ln);
+ return;
+ }
+ }
+ /* this shouldn't happen ever */
+ assert(0);
+}
+
+/* each call to find_cycle records a cycle in cycle, to break at node c.
+ * this will stop eventually.
+ */
+static void
+break_and_print_cycles(Lst t)
+{
+ struct growableArray cycle;
+
+ Array_Init(&cycle, 16); /* cycles are generally shorter */
+ while (1) {
+ GNode *c;
+
+ Array_Reset(&cycle);
+ c = find_cycle(t, &cycle);
+ if (c)
+ print_unlink_cycle(&cycle, c);
+ else
+ break;
+ }
+ free(cycle.a);
+}
+
+
+static GNode *
+find_cycle(Lst l, struct growableArray *cycle)
+{
+ LstNode ln;
+
+ for (ln = Lst_First(l); ln != NULL; ln = Lst_Adv(ln)) {
+ GNode *gn = Lst_Datum(ln);
+ if (gn->in_cycle) {
+ /* we should print the cycle and not do more */
+ return gn;
+ }
+
+ if (gn->built_status == UPTODATE)
+ continue;
+ if (gn->unmade != 0) {
+ GNode *c;
+
+ gn->in_cycle = true;
+ Array_Push(cycle, gn);
+ c = find_cycle(&gn->children, cycle);
+ gn->in_cycle = false;
+ if (c)
+ return c;
+ Array_Pop(cycle);
+ }
+ }
+ return NULL;
+}
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