PR middle-end/46534

	* builtins.c (fold_builtin_printf): Don't copy and modify string
	before build_string_literal, instead modify what
	build_string_literal returned.

	* gcc.c-torture/compile/pr46534.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@166918 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5375091..12eaf9c 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2010-11-18  Jakub Jelinek  <jakub@redhat.com>
+
+       PR middle-end/46534
+       * builtins.c (fold_builtin_printf): Don't copy and modify string
+       before build_string_literal, instead modify what
+       build_string_literal returned.
+
 2010-11-18  Nathan Froyd  <froydnj@codesourcery.com>
 
        PR c/33193

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 5f2959c..c9e8e68 100644 (file)
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -12892,15 +12892,28 @@ fold_builtin_printf (location_t loc, tree fndecl, tree fmt,
        {
          /* If the string was "string\n", call puts("string").  */
          size_t len = strlen (str);
-         if ((unsigned char)str[len - 1] == target_newline)
+         if ((unsigned char)str[len - 1] == target_newline
+             && (size_t) (int) len == len
+             && (int) len > 0)
            {
+             char *newstr;
+             tree offset_node, string_cst;
+
              /* Create a NUL-terminated string that's one char shorter
                 than the original, stripping off the trailing '\n'.  */
-             char *newstr = XALLOCAVEC (char, len);
-             memcpy (newstr, str, len - 1);
-             newstr[len - 1] = 0;
-
-             newarg = build_string_literal (len, newstr);
+             newarg = build_string_literal (len, str);
+             string_cst = string_constant (newarg, &offset_node);
+             gcc_checking_assert (string_cst
+                                  && (TREE_STRING_LENGTH (string_cst)
+                                      == (int) len)
+                                  && integer_zerop (offset_node)
+                                  && (unsigned char)
+                                     TREE_STRING_POINTER (string_cst)[len - 1]
+                                     == target_newline);
+             /* build_string_literal creates a new STRING_CST,
+                modify it in place to avoid double copying.  */
+             newstr = CONST_CAST (char *, TREE_STRING_POINTER (string_cst));
+             newstr[len - 1] = '\0';
              if (fn_puts)
                call = build_call_expr_loc (loc, fn_puts, 1, newarg);
            }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7ef06b1..e349b19 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-18  Jakub Jelinek  <jakub@redhat.com>
+
+       PR middle-end/46534
+       * gcc.c-torture/compile/pr46534.c: New test.
+
 2010-11-18  Eric Botcazou  <ebotcazou@adacore.com>
 
        * gnat.dg/atomic4.ad[sb]: New test.

diff --git a/gcc/testsuite/gcc.c-torture/compile/pr46534.c b/gcc/testsuite/gcc.c-torture/compile/pr46534.c
new file mode 100644 (file)
index 0000000..3023ad9
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr46534.c
@@ -0,0 +1,17 @@
+/* PR middle-end/46534 */
+
+extern int printf (const char *, ...);
+
+#define S1 "                    "
+#define S2 S1 S1 S1 S1 S1 S1 S1 S1 S1 S1
+#define S3 S2 S2 S2 S2 S2 S2 S2 S2 S2 S2
+#define S4 S3 S3 S3 S3 S3 S3 S3 S3 S3 S3
+#define S5 S4 S4 S4 S4 S4 S4 S4 S4 S4 S4
+#define S6 S5 S5 S5 S5 S5 S5 S5 S5 S5 S5
+#define S7 S6 S6 S6 S6 S6 S6 S6 S6 S6 S6
+
+void
+foo (void)
+{
+  printf (S7 "\n");
+}