* c-typeck.c (build_array_ref): Don't check for index == 0. Make

	checks for neither argument being an array or pointer (swapping
	the arguments if necessary), the array argument being a pointer to
	or array of functions and for -Wchar-subscripts warnings upfront.

testsuite:
	* gcc.dg/Wchar-subscripts-1.c, gcc.dg/array-8.c: New tests.
	* gcc.dg/pointer-arith-1.c, gcc.dg/pointer-arith-2.c,
	gcc.dg/pointer-arith-3.c, gcc.dg/pointer-arith-4.c: Update
	expected diagnostics.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@90969 138bc75d-0d04-0410-961f-82ee72b054a4

7 files changed, 93 insertions, 8 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8fe6b3b60ef..ef3ca31020f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2004-11-20  Joseph S. Myers  <joseph@codesourcery.com>
+
+	* gcc.dg/Wchar-subscripts-1.c, gcc.dg/array-8.c: New tests.
+	* gcc.dg/pointer-arith-1.c, gcc.dg/pointer-arith-2.c,
+	gcc.dg/pointer-arith-3.c, gcc.dg/pointer-arith-4.c: Update
+	expected diagnostics.
+
 2004-11-20  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
 	PR target/18580
diff --git a/gcc/testsuite/gcc.dg/Wchar-subscripts-1.c b/gcc/testsuite/gcc.dg/Wchar-subscripts-1.c
new file mode 100644
index 00000000000..d1efd25026b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wchar-subscripts-1.c
@@ -0,0 +1,29 @@
+/* Test -Wchar-subscripts.  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-Wchar-subscripts" } */
+
+extern int a[];
+int *p;
+char c;
+signed char sc;
+unsigned char uc;
+
+void
+f (void)
+{
+  a[sc];
+  a[uc];
+  sc[a];
+  uc[a];
+  p[sc];
+  p[uc];
+  sc[p];
+  uc[p];
+  a[c]; /* { dg-warning "warning: array subscript has type 'char'" } */
+  p[c]; /* { dg-warning "warning: array subscript has type 'char'" } */
+  /* -Wchar-subscripts does not warn if the char is not syntactically
+      the subscript.  */
+  c[a];
+  c[p];
+}
diff --git a/gcc/testsuite/gcc.dg/array-8.c b/gcc/testsuite/gcc.dg/array-8.c
new file mode 100644
index 00000000000..6d0a211461b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/array-8.c
@@ -0,0 +1,49 @@
+/* Test diagnostics for array references.  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu89" } */
+
+struct s { char c[1]; };
+struct s f (void);
+_Bool b;
+char c;
+enum e { E } e;
+extern int a[];
+int *p;
+void *pv;
+void (*fp)(void);
+struct si *sip;
+
+void
+g (void)
+{
+  a[b];
+  a[c];
+  a[e];
+  p[b];
+  p[c];
+  p[e];
+  b[a];
+  c[a];
+  e[a];
+  b[p];
+  c[p];
+  e[p];
+  /* These two should be treated the same.  In particular, a "neither
+     array nor pointer" bogus warning used to be given for the
+     second.  */
+  f().c[0];
+  0[f().c];
+  /* Various invalid cases.  */
+  c[c]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
+  p[1.0]; /* { dg-error "error: array subscript is not an integer" } */
+  1.0[a]; /* { dg-error "error: array subscript is not an integer" } */
+  fp[0]; /* { dg-error "error: subscripted value is pointer to function" } */
+  0[fp]; /* { dg-error "error: subscripted value is pointer to function" } */
+  pv[0]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
+  0[pv]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
+  sip[0]; /* { dg-error "error: invalid use of undefined type 'struct si'" } */
+  /* { dg-error "error: dereferencing pointer to incomplete type" "" { target *-*-* } 45 } */
+  0[sip]; /* { dg-error "error: invalid use of undefined type 'struct si'" } */
+  /* { dg-error "error: dereferencing pointer to incomplete type" "" { target *-*-* } 47 } */
+}
diff --git a/gcc/testsuite/gcc.dg/pointer-arith-1.c b/gcc/testsuite/gcc.dg/pointer-arith-1.c
index fec20547bf3..3bf78873e8f 100644
--- a/gcc/testsuite/gcc.dg/pointer-arith-1.c
+++ b/gcc/testsuite/gcc.dg/pointer-arith-1.c
@@ -32,8 +32,8 @@ g (void)
   f -= 1;
   p[0]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
   0[p]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
-  f[0]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
-  0[f]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
+  f[0]; /* { dg-error "error: subscripted value is pointer to function" } */
+  0[f]; /* { dg-error "error: subscripted value is pointer to function" } */
   p - p;
   f - f;
 }
diff --git a/gcc/testsuite/gcc.dg/pointer-arith-2.c b/gcc/testsuite/gcc.dg/pointer-arith-2.c
index 8e95ab52078..fde01e102d7 100644
--- a/gcc/testsuite/gcc.dg/pointer-arith-2.c
+++ b/gcc/testsuite/gcc.dg/pointer-arith-2.c
@@ -34,8 +34,8 @@ g (void)
   /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 33 } */
   0[p]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
   /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 35 } */
-  f[0]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
-  0[f]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
+  f[0]; /* { dg-error "error: subscripted value is pointer to function" } */
+  0[f]; /* { dg-error "error: subscripted value is pointer to function" } */
   p - p; /* { dg-warning "warning: pointer of type 'void \\*' used in subtraction" } */
   f - f; /* { dg-warning "warning: pointer to a function used in subtraction" } */
 }
diff --git a/gcc/testsuite/gcc.dg/pointer-arith-3.c b/gcc/testsuite/gcc.dg/pointer-arith-3.c
index 90f524101b8..f23f677c8b8 100644
--- a/gcc/testsuite/gcc.dg/pointer-arith-3.c
+++ b/gcc/testsuite/gcc.dg/pointer-arith-3.c
@@ -34,8 +34,8 @@ g (void)
   /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 33 } */
   0[p]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
   /* { dg-warning "warning: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 35 } */
-  f[0]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
-  0[f]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
+  f[0]; /* { dg-error "error: subscripted value is pointer to function" } */
+  0[f]; /* { dg-error "error: subscripted value is pointer to function" } */
   p - p; /* { dg-warning "warning: pointer of type 'void \\*' used in subtraction" } */
   f - f; /* { dg-warning "warning: pointer to a function used in subtraction" } */
 }
diff --git a/gcc/testsuite/gcc.dg/pointer-arith-4.c b/gcc/testsuite/gcc.dg/pointer-arith-4.c
index 3e577fc1cb5..b17f9d7a335 100644
--- a/gcc/testsuite/gcc.dg/pointer-arith-4.c
+++ b/gcc/testsuite/gcc.dg/pointer-arith-4.c
@@ -34,8 +34,8 @@ g (void)
   /* { dg-error "error: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 33 } */
   0[p]; /* { dg-warning "warning: dereferencing 'void \\*' pointer" } */
   /* { dg-error "error: pointer of type 'void \\*' used in arithmetic" "array 1" { target *-*-* } 35 } */
-  f[0]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
-  0[f]; /* { dg-error "error: subscripted value is neither array nor pointer" } */
+  f[0]; /* { dg-error "error: subscripted value is pointer to function" } */
+  0[f]; /* { dg-error "error: subscripted value is pointer to function" } */
   p - p; /* { dg-error "error: pointer of type 'void \\*' used in subtraction" } */
   f - f; /* { dg-error "error: pointer to a function used in subtraction" } */
 }