c-typeck.c (build_conditional_expr): Do not allow non-lvalue arrays.

	* c-typeck.c (build_conditional_expr): Do not allow non-lvalue
	arrays.

testsuite:
	* gcc.dg/c90-array-lval-7.c, gcc.dg/c99-array-lval-7.c: New tests.

From-SVN: r76477

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 12884b7..fb51395 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-01-24  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+       * c-typeck.c (build_conditional_expr): Do not allow non-lvalue
+       arrays.
+
 2004-01-23  Kazu Hirata  <kazu@cs.umass.edu>
 
        * recog.c: Fix a typo in copyright.

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index b6a5d9e..367285e 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -2651,6 +2651,14 @@ build_conditional_expr (tree ifexp, tree op1, tree op2)
   type2 = TREE_TYPE (op2);
   code2 = TREE_CODE (type2);
 
+  /* C90 does not permit non-lvalue arrays in conditional expressions.
+     In C99 they will be pointers by now.  */
+  if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
+    {
+      error ("non-lvalue array in conditional expression");
+      return error_mark_node;
+    }
+
   /* Quickly detect the usual case where op1 and op2 have the same type
      after promotion.  */
   if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 26a900a..ecca656 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2004-01-24  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+       * gcc.dg/c90-array-lval-7.c, gcc.dg/c99-array-lval-7.c: New tests.
+
 2004-01-23  Andrew Pinski  <apinski@apple.com>
 
        * gcc.dg/20030121-1.c: Move to ..

diff --git a/gcc/testsuite/gcc.dg/c90-array-lval-7.c b/gcc/testsuite/gcc.dg/c90-array-lval-7.c
new file mode 100644 (file)
index 0000000..ee8da4c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c90-array-lval-7.c
@@ -0,0 +1,23 @@
+/* Test for non-lvalue arrays: test that C90 does not allow them in
+   conditional expressions, while in C99 they decay and are
+   allowed.  */
+
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1990 -pedantic-errors" } */
+
+struct s { char c[1]; };
+struct s a, b, c;
+int d;
+int e;
+
+void
+bar (void)
+{
+  /* In C90, the non-lvalue arrays do not decay to pointers, and
+     6.3.15 does not permit conditional expressions between arrays.
+     In C99, they decay to pointers.  */
+  (e ? (d ? b : c).c : (e ? b : c).c); /* { dg-bogus "warning" "warning in place of error" } */
+}
+
+/* { dg-error "array" "bad conditional" { target *-*-* } 20 } */

diff --git a/gcc/testsuite/gcc.dg/c99-array-lval-7.c b/gcc/testsuite/gcc.dg/c99-array-lval-7.c
new file mode 100644 (file)
index 0000000..3d70ed0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c99-array-lval-7.c
@@ -0,0 +1,21 @@
+/* Test for non-lvalue arrays: test that C90 does not allow them in
+   conditional expressions, while in C99 they decay and are
+   allowed.  */
+
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors" } */
+
+struct s { char c[1]; };
+struct s a, b, c;
+int d;
+int e;
+
+void
+bar (void)
+{
+  /* In C90, the non-lvalue arrays do not decay to pointers, and
+     6.3.15 does not permit conditional expressions between arrays.
+     In C99, they decay to pointers.  */
+  (e ? (d ? b : c).c : (e ? b : c).c);
+}