Fold arithmetic integer expressions

Commit b751e639 regressed arm linux kernel builds, that have an
ASSERT (((__hyp_idmap_text_end - (__hyp_idmap_text_start
       			          & ~ (((0x1 << 0xc) - 0x1))))
         <= (0x1 << 0xc)), HYP init code too big or misaligned)

Due to some insanity in ld expression evaluation, the integer values
0x1 and 0xc above are treated as absolute addresses (ie. they have an
associated section, *ABS*, see exp_fold_tree_1 case etree_value) while
the expression (0x1 << 0xc) has a plain number result.  The left hand
side of the inequality happens to evaluate to a "negative" .text
section relative value.  Comparing a section relative value against an
absolute value works since the section relative value is first
converted to absolute.  Comparing a section relative value against a
number just compares the offsets, which fails since the "negative"
offset is really a very large positive number.

This patch works around the problem by folding integer expressions, so
the assert again becomes
ASSERT (((__hyp_idmap_text_end - (__hyp_idmap_text_start
       			          & 0xfffffffffffff000))
         <= 0x1000), HYP init code too big or misaligned)

	* ldexp.c (exp_value_fold): New function.
	(exp_unop, exp_binop, exp_trinop): Use it.

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 3ad2a7affa6f556aab36e06f98d234bbc55ac7ae..8b22c50a1f31f2aa4ad0def90e767eb619b392fc 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2016-10-04  Alan Modra  <amodra@gmail.com>
+
+       * ldexp.c (exp_value_fold): New function.
+       (exp_unop, exp_binop, exp_trinop): Use it.
+
 2016-09-30  Alan Modra  <amodra@gmail.com>
 
        * scripttempl/v850.sc: Don't reference __ctbp, __ep, __gp when

diff --git a/ld/ldexp.c b/ld/ldexp.c
index a560643fb330e014bfd21521b16e2e76261cfe80..9f88144b67819df658b5abbcaf3217f28a0f1422 100644 (file)
--- a/ld/ldexp.c
+++ b/ld/ldexp.c
@@ -1252,6 +1252,19 @@ exp_fold_tree_no_dot (etree_type *tree)
   exp_fold_tree_1 (tree);
 }
 
+static void
+exp_value_fold (etree_type *tree)
+{
+  exp_fold_tree_no_dot (tree);
+  if (expld.result.valid_p)
+    {
+      tree->type.node_code = INT;
+      tree->value.value = expld.result.value;
+      tree->value.str = NULL;
+      tree->type.node_class = etree_value;
+    }
+}
+
 etree_type *
 exp_binop (int code, etree_type *lhs, etree_type *rhs)
 {
@@ -1263,6 +1276,12 @@ exp_binop (int code, etree_type *lhs, etree_type *rhs)
   new_e->binary.lhs = lhs;
   new_e->binary.rhs = rhs;
   new_e->type.node_class = etree_binary;
+  if (lhs->type.node_class == etree_value
+      && rhs->type.node_class == etree_value
+      && code != ALIGN_K
+      && code != DATA_SEGMENT_ALIGN
+      && code != DATA_SEGMENT_RELRO_END)
+    exp_value_fold (new_e);
   return new_e;
 }
 
@@ -1278,6 +1297,10 @@ exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs)
   new_e->trinary.cond = cond;
   new_e->trinary.rhs = rhs;
   new_e->type.node_class = etree_trinary;
+  if (cond->type.node_class == etree_value
+      && lhs->type.node_class == etree_value
+      && rhs->type.node_class == etree_value)
+    exp_value_fold (new_e);
   return new_e;
 }
 
@@ -1291,6 +1314,12 @@ exp_unop (int code, etree_type *child)
   new_e->unary.type.lineno = child->type.lineno;
   new_e->unary.child = child;
   new_e->unary.type.node_class = etree_unary;
+  if (child->type.node_class == etree_value
+      && code != ALIGN_K
+      && code != ABSOLUTE
+      && code != NEXT
+      && code != DATA_SEGMENT_END)
+    exp_value_fold (new_e);
   return new_e;
 }