LoongArch: Fix symbol size after relaxation

There's a logic error in loongarch_relax_perform_deletes: when there's
not any delete operation of which the start address is strictly smaller
than the symbol address, splay_tree_predecessor() will return nullptr
and the symbol size will be unchanged even if some bytes of it are
removed.

Make the logic more complete to fix this issue.  Also factor out the
symbol size adjustment logic into a function to avoid code bloating.

Tested-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>

diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 1ddea2f4f8c9c796fcb23009826642d58fe85064..8beb3d8407957c3b697d363346dc218f057988a4 100644 (file)
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -4903,6 +4903,60 @@ loongarch_relax_delete_or_nop (bfd *abfd,
     bfd_put (32, abfd, LARCH_NOP, contents + addr);
 }
 
+/* If some bytes in a symbol is deleted, we need to adjust its size.  */
+static void
+loongarch_relax_resize_symbol (bfd_size_type *size, bfd_vma orig_value,
+                              splay_tree pdops)
+{
+  splay_tree_key key = (splay_tree_key)orig_value;
+  bfd_vma orig_end = orig_value + *size;
+  splay_tree_node node = splay_tree_predecessor (pdops, key);
+
+  if (node)
+    {
+      bfd_vma addr = (bfd_vma)node->key;
+      struct pending_delete_op *op = (struct pending_delete_op *)node->value;
+
+      /* This shouldn't happen unless people write something really insane like
+            .reloc ., R_LARCH_ALIGN, 60
+            .rept 15
+            1: nop
+            .endr
+            .set x, 1b
+            .size x, . - 1b
+        But let's just try to make it "work" anyway.  */
+      if (orig_value < addr + op->size)
+       {
+         bfd_size_type n_deleted = op->size - (orig_value - addr);
+         if (n_deleted >= *size)
+           {
+             *size = 0;
+             return;
+           }
+
+         *size -= n_deleted;
+       }
+    }
+
+  node = splay_tree_lookup (pdops, key);
+  if (!node)
+    node = splay_tree_successor (pdops, key);
+
+  for (; node; node = splay_tree_successor (pdops, node->key))
+    {
+      bfd_vma addr = (bfd_vma)node->key;
+      struct pending_delete_op *op = (struct pending_delete_op *)node->value;
+
+      if (addr >= orig_end)
+       return;
+
+      if (orig_end < addr + op->size)
+       *size -= orig_end - addr;
+      else
+       *size -= op->size;
+    }
+}
+
 static void
 loongarch_relax_perform_deletes (bfd *abfd, asection *sec,
                                 struct bfd_link_info *link_info)
@@ -5001,30 +5055,8 @@ loongarch_relax_perform_deletes (bfd *abfd, asection *sec,
            sym->st_value
                = loongarch_calc_relaxed_addr (link_info, orig_value);
 
-         /* If the symbol *spans* some deleted bytes, that is its *end* is in
-            the moved bytes but its *start* isn't, then we must adjust its
-            size.
-
-            This test needs to use the original value of st_value, otherwise
-            we might accidentally decrease size when deleting bytes right
-            before the symbol.  */
-         bfd_vma sym_end = orig_value + sym->st_size;
-         if (sym_end <= toaddr)
-           {
-             splay_tree_node node = splay_tree_predecessor (
-                 pdops, (splay_tree_key)orig_value);
-             for (; node; node = splay_tree_successor (pdops, node->key))
-               {
-                 bfd_vma addr = (bfd_vma)node->key;
-                 struct pending_delete_op *op
-                     = (struct pending_delete_op *)node->value;
-
-                 if (addr >= sym_end)
-                   break;
-                 if (orig_value <= addr && sym_end > addr)
-                   sym->st_size -= op->size;
-               }
-           }
+         if (orig_value + sym->st_size <= toaddr)
+           loongarch_relax_resize_symbol (&sym->st_size, orig_value, pdops);
        }
     }
 
@@ -5071,29 +5103,13 @@ loongarch_relax_perform_deletes (bfd *abfd, asection *sec,
        {
          bfd_vma orig_value = sym_hash->root.u.def.value;
 
-         /* As above, adjust the value.  */
+         /* As above, adjust the value and size.  */
          if (orig_value <= toaddr)
            sym_hash->root.u.def.value
                = loongarch_calc_relaxed_addr (link_info, orig_value);
 
-         /* As above, adjust the size if needed.  */
-         bfd_vma sym_end = orig_value + sym_hash->size;
-         if (sym_end <= toaddr)
-           {
-             splay_tree_node node = splay_tree_predecessor (
-                 pdops, (splay_tree_key)orig_value);
-             for (; node; node = splay_tree_successor (pdops, node->key))
-               {
-                 bfd_vma addr = (bfd_vma)node->key;
-                 struct pending_delete_op *op
-                     = (struct pending_delete_op *)node->value;
-
-                 if (addr >= sym_end)
-                   break;
-                 if (orig_value <= addr && sym_end > addr)
-                   sym_hash->size -= op->size;
-               }
-           }
+         if (orig_value + sym_hash->size <= toaddr)
+           loongarch_relax_resize_symbol (&sym_hash->size, orig_value, pdops);
        }
     }
 }

diff --git a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
index e23cdc87161077d20014ac5f59410f0f928c5cd9..a33727f2efd83976f128615005170b5e1363d1f7 100644 (file)
--- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
+++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
@@ -48,6 +48,8 @@ if [istarget "loongarch64-*-*"] {
     run_dump_test "relax-after-alignment"
     run_dump_test "relax-medium-call"
     run_dump_test "relax-medium-call-1"
+    run_dump_test "relax-sym-size-1"
+    run_dump_test "relax-sym-size-2"
     run_dump_test "check_got_relax"
 }
 

diff --git a/ld/testsuite/ld-loongarch-elf/relax-sym-size-1.d b/ld/testsuite/ld-loongarch-elf/relax-sym-size-1.d
new file mode 100644 (file)
index 0000000..eec989f
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/relax-sym-size-1.d
@@ -0,0 +1,7 @@
+#source: relax-sym-size-1.s
+#ld:
+#readelf: -s
+
+#...
+ *[0-9]+: [0-9a-z]+ +8 .* _start
+#...

diff --git a/ld/testsuite/ld-loongarch-elf/relax-sym-size-1.s b/ld/testsuite/ld-loongarch-elf/relax-sym-size-1.s
new file mode 100644 (file)
index 0000000..c70ac71
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/relax-sym-size-1.s
@@ -0,0 +1,8 @@
+.p2align 2
+bar:
+  nop
+.globl _start
+_start:
+  la.pcrel $a0, bar
+  ret
+.size _start, . - _start

diff --git a/ld/testsuite/ld-loongarch-elf/relax-sym-size-2.d b/ld/testsuite/ld-loongarch-elf/relax-sym-size-2.d
new file mode 100644 (file)
index 0000000..1388099
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/relax-sym-size-2.d
@@ -0,0 +1,7 @@
+#source: relax-sym-size-2.s
+#ld:
+#readelf: -s
+
+#...
+ *[0-9]+: [0-9a-z]+ +64 .* _start
+#...

diff --git a/ld/testsuite/ld-loongarch-elf/relax-sym-size-2.s b/ld/testsuite/ld-loongarch-elf/relax-sym-size-2.s
new file mode 100644 (file)
index 0000000..e02e16b
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/relax-sym-size-2.s
@@ -0,0 +1,19 @@
+bar:
+  nop
+.p2align 6
+
+.reloc ., R_LARCH_ALIGN, 60
+.rept 15
+  1: nop
+.endr
+  la.pcrel $a0, bar
+  ret
+
+.reloc ., R_LARCH_ALIGN, 60
+.rept 15
+  2: nop
+.endr
+
+.globl _start
+.set _start, 1b
+.size _start, 2b - 1b