Hi!
If users use attributes like const or pure incorrectly on stringops
builtins, the tree-ssa-strlen.c pass can ICE, because it expects it can e.g.
replace a strcpy (which should not be const or pure) with memcpy (which also
shouldn't be const/pure) etc.
The patch just pretends the calls aren't builtins for the purpose of
tree-ssa-strlen.c pass if they have unexpected const/pure-ness.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/6.2?
2016-06-20 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/71588
* tree-ssa-strlen.c (valid_builtin_call): New function.
(adjust_last_stmt, handle_builtin_memset, strlen_optimize_stmt): Use
it.
* gcc.dg/pr71558.c: New test.
--- gcc/tree-ssa-strlen.c.jj 2016-06-08 14:51:25.000000000 +0200
+++ gcc/tree-ssa-strlen.c 2016-06-20 13:30:23.576556803 +0200
@@ -860,6 +860,66 @@ find_equal_ptrs (tree ptr, int idx)
}
}
+/* Return true if STMT is a call to a builtin function with the right
+ arguments and attributes that should be considered for optimization
+ by this pass. */
+
+static bool
+valid_builtin_call (gimple *stmt)
+{
+ if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
+ return false;
+
+ tree callee = gimple_call_fndecl (stmt);
+ switch (DECL_FUNCTION_CODE (callee))
+ {
+ case BUILT_IN_MEMCMP:
+ case BUILT_IN_MEMCMP_EQ:
+ case BUILT_IN_STRCHR:
+ case BUILT_IN_STRCHR_CHKP:
+ case BUILT_IN_STRLEN:
+ case BUILT_IN_STRLEN_CHKP:
+ /* The above functions should be pure. Punt if they aren't. */
+ if (gimple_vdef (stmt) || gimple_vuse (stmt) == NULL_TREE)
+ return false;
+ break;
+
+ case BUILT_IN_CALLOC:
+ case BUILT_IN_MALLOC:
+ case BUILT_IN_MEMCPY:
+ case BUILT_IN_MEMCPY_CHK:
+ case BUILT_IN_MEMCPY_CHKP:
+ case BUILT_IN_MEMCPY_CHK_CHKP:
+ case BUILT_IN_MEMPCPY:
+ case BUILT_IN_MEMPCPY_CHK:
+ case BUILT_IN_MEMPCPY_CHKP:
+ case BUILT_IN_MEMPCPY_CHK_CHKP:
+ case BUILT_IN_MEMSET:
+ case BUILT_IN_STPCPY:
+ case BUILT_IN_STPCPY_CHK:
+ case BUILT_IN_STPCPY_CHKP:
+ case BUILT_IN_STPCPY_CHK_CHKP:
+ case BUILT_IN_STRCAT:
+ case BUILT_IN_STRCAT_CHK:
+ case BUILT_IN_STRCAT_CHKP:
+ case BUILT_IN_STRCAT_CHK_CHKP:
+ case BUILT_IN_STRCPY:
+ case BUILT_IN_STRCPY_CHK:
+ case BUILT_IN_STRCPY_CHKP:
+ case BUILT_IN_STRCPY_CHK_CHKP:
+ /* The above functions should be neither const nor pure. Punt if they
+ aren't. */
+ if (gimple_vdef (stmt) == NULL_TREE || gimple_vuse (stmt) == NULL_TREE)
+ return false;
+ break;
+
+ default:
+ break;
+ }
+
+ return true;
+}
+
/* If the last .MEM setter statement before STMT is
memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT
and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to
@@ -935,7 +995,7 @@ adjust_last_stmt (strinfo *si, gimple *s
return;
}
- if (!gimple_call_builtin_p (last.stmt, BUILT_IN_NORMAL))
+ if (!valid_builtin_call (last.stmt))
return;
callee = gimple_call_fndecl (last.stmt);
@@ -1811,7 +1871,7 @@ handle_builtin_memset (gimple_stmt_itera
if (!stmt1 || !is_gimple_call (stmt1))
return true;
tree callee1 = gimple_call_fndecl (stmt1);
- if (!gimple_call_builtin_p (stmt1, BUILT_IN_NORMAL))
+ if (!valid_builtin_call (stmt1))
return true;
enum built_in_function code1 = DECL_FUNCTION_CODE (callee1);
tree size = gimple_call_arg (stmt2, 2);
@@ -2140,7 +2200,7 @@ strlen_optimize_stmt (gimple_stmt_iterat
if (is_gimple_call (stmt))
{
tree callee = gimple_call_fndecl (stmt);
- if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
+ if (valid_builtin_call (stmt))
switch (DECL_FUNCTION_CODE (callee))
{
case BUILT_IN_STRLEN:
--- gcc/testsuite/gcc.dg/pr71558.c.jj 2016-06-20 13:52:15.491591442 +0200
+++ gcc/testsuite/gcc.dg/pr71558.c 2016-06-20 13:51:59.000000000 +0200
@@ -0,0 +1,17 @@
+/* PR tree-optimization/71588 */
+
+/* strcpy must not be pure, but make sure we don't ICE even when
+ it is declared incorrectly. */
+char *strcpy (char *, const char *) __attribute__ ((__pure__));
+__SIZE_TYPE__ strlen (const char *);
+void *malloc (__SIZE_TYPE__);
+
+char a[20];
+
+char *
+foo (void)
+{
+ __SIZE_TYPE__ b = strlen (a);
+ char *c = malloc (b);
+ return strcpy (c, a);
+}
Jakub
