From 3d9ee7d24be691e8b89cb5ebf0db744be279d8db Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Mon, 14 Oct 2019 13:57:01 +1030 Subject: [PATCH] qsort: ldctor.c CONSTRUCTORS ctor_cmp had an ineffective comparison of addresses in an attempt to ensure sort stability. Comparing the addresses passed to the comparison function can't work since those addresses may be from an array that is already perturbed by qsort. * ldctor.h (struct set_element): Make next field a union, adding idx field. * ldctor.c (ctor_cmp): Dereference pointer and lose unnecessary const. Replace final sort on pointer value with final sort on idx. (ldctor_add_set_entry): Adjust next field access. (ldctor_build_sets): Likewise. Set u.idx field for sort. --- ld/ChangeLog | 9 +++++++++ ld/ldctor.c | 38 ++++++++++++++++++-------------------- ld/ldctor.h | 5 ++++- 3 files changed, 31 insertions(+), 21 deletions(-) diff --git a/ld/ChangeLog b/ld/ChangeLog index 19ed0b5f21c..f8dca8633f7 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,12 @@ +2019-10-14 Alan Modra + + * ldctor.h (struct set_element): Make next field a union, adding + idx field. + * ldctor.c (ctor_cmp): Dereference pointer and lose unnecessary + const. Replace final sort on pointer value with final sort on idx. + (ldctor_add_set_entry): Adjust next field access. + (ldctor_build_sets): Likewise. Set u.idx field for sort. + 2019-10-14 Alan Modra * pe-dll.c (reloc_data_type): Add idx field. diff --git a/ld/ldctor.c b/ld/ldctor.c index ba8cac1e353..881ca258cbc 100644 --- a/ld/ldctor.c +++ b/ld/ldctor.c @@ -106,12 +106,12 @@ ldctor_add_set_entry (struct bfd_link_hash_entry *h, } e = (struct set_element *) xmalloc (sizeof (struct set_element)); - e->next = NULL; + e->u.next = NULL; e->name = name; e->section = section; e->value = value; - for (epp = &p->elements; *epp != NULL; epp = &(*epp)->next) + for (epp = &p->elements; *epp != NULL; epp = &(*epp)->u.next) ; *epp = e; @@ -152,19 +152,17 @@ ctor_prio (const char *name) static int ctor_cmp (const void *p1, const void *p2) { - const struct set_element *const *pe1 - = (const struct set_element *const *) p1; - const struct set_element *const *pe2 - = (const struct set_element *const *) p2; + const struct set_element *pe1 = *(const struct set_element **) p1; + const struct set_element *pe2 = *(const struct set_element **) p2; const char *n1; const char *n2; int prio1; int prio2; - n1 = (*pe1)->name; + n1 = pe1->name; if (n1 == NULL) n1 = ""; - n2 = (*pe2)->name; + n2 = pe2->name; if (n2 == NULL) n2 = ""; @@ -178,17 +176,15 @@ ctor_cmp (const void *p1, const void *p2) /* We sort in reverse order because that is what g++ expects. */ if (prio1 < prio2) return 1; - else if (prio1 > prio2) + if (prio1 > prio2) return -1; /* Force a stable sort. */ - - if (pe1 < pe2) + if (pe1->u.idx < pe2->u.idx) return -1; - else if (pe1 > pe2) + if (pe1->u.idx > pe2->u.idx) return 1; - else - return 0; + return 0; } /* This function is called after the first phase of the link and @@ -214,22 +210,24 @@ ldctor_build_sets (void) for (p = sets; p != NULL; p = p->next) { int c, i; - struct set_element *e; + struct set_element *e, *enext; struct set_element **array; if (p->elements == NULL) continue; c = 0; - for (e = p->elements; e != NULL; e = e->next) + for (e = p->elements; e != NULL; e = e->u.next) ++c; array = (struct set_element **) xmalloc (c * sizeof *array); i = 0; - for (e = p->elements; e != NULL; e = e->next) + for (e = p->elements; e != NULL; e = enext) { array[i] = e; + enext = e->u.next; + e->u.idx = i; ++i; } @@ -238,8 +236,8 @@ ldctor_build_sets (void) e = array[0]; p->elements = e; for (i = 0; i < c - 1; i++) - array[i]->next = array[i + 1]; - array[i]->next = NULL; + array[i]->u.next = array[i + 1]; + array[i]->u.next = NULL; free (array); } @@ -334,7 +332,7 @@ ldctor_build_sets (void) FALSE)); lang_add_data (size, exp_intop (p->count)); - for (e = p->elements; e != NULL; e = e->next) + for (e = p->elements; e != NULL; e = e->u.next) { if (config.map_file != NULL) { diff --git a/ld/ldctor.h b/ld/ldctor.h index fa21277fe63..b48a0dbb635 100644 --- a/ld/ldctor.h +++ b/ld/ldctor.h @@ -40,7 +40,10 @@ struct set_info { }; struct set_element { - struct set_element *next; /* Next element. */ + union { + struct set_element *next; /* Next element. */ + long idx; + } u; const char *name; /* Name in set (may be NULL). */ asection *section; /* Section of value in set. */ bfd_vma value; /* Value in set. */ -- 2.30.2