[gcc(refs/users/marxin/heads/marxin-gcc-benchmark-branch)] c: After issuing errors about array size, for error-recovery don't make the array VLA [PR93573]

[Martin Liska]

https://gcc.gnu.org/g:c6a562de88c44a555e1688c212869b20b02151bc

commit c6a562de88c44a555e1688c212869b20b02151bc
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Sat Mar 28 10:30:31 2020 +0100

    c: After issuing errors about array size, for error-recovery don't make the array VLA [PR93573]
    
    After we report various errors about array size, we set for error-recovery
    the size to be 1, but because size_int_const is false, it still means we
    pretend the array is a VLA, can emit a second diagnostics in that case etc.
    E.g.
    $ ./cc1.unpatched -quiet a.c
    a.c:1:5: error: size of array ‘f’ has non-integer type
        1 | int f[100.0];
          |     ^
    a.c:1:1: warning: variably modified ‘f’ at file scope
        1 | int f[100.0];
          | ^~~
    $ ./cc1 -quiet a.c
    a.c:1:5: error: size of array ‘f’ has non-integer type
        1 | int f[100.0];
          |     ^
    
    2020-03-28  Jakub Jelinek  <jakub@redhat.com>
    
            PR c/93573
            * c-decl.c (grokdeclarator): After issuing errors, set size_int_const
            to true after setting size to integer_one_node.
    
            * gcc.dg/pr93573-1.c: New test.
            * gcc.dg/pr93573-2.c: New test.

Diff:
---
 gcc/ChangeLog                    |  4 ++++
 gcc/c/c-decl.c                   |  3 +++
 gcc/testsuite/ChangeLog          |  4 ++++
 gcc/testsuite/gcc.dg/pr93573-1.c | 12 ++++++++++++
 gcc/testsuite/gcc.dg/pr93573-2.c |  6 ++++++
 5 files changed, 29 insertions(+)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 52c296c00ae..86ad683a6cb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2020-03-28  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c/93573
+	* c-decl.c (grokdeclarator): After issuing errors, set size_int_const
+	to true after setting size to integer_one_node.
+
 	PR tree-optimization/94329
 	* tree-ssa-reassoc.c (reassociate_bb): When calling reassoc_remove_stmt
 	on the last stmt in a bb, make sure gsi_prev isn't done immediately
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 80fe3186759..b31d99fcfaf 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -6416,6 +6416,7 @@ grokdeclarator (const struct c_declarator *declarator,
 		      error_at (loc,
 				"size of unnamed array has non-integer type");
 		    size = integer_one_node;
+		    size_int_const = true;
 		  }
 		/* This can happen with enum forward declaration.  */
 		else if (!COMPLETE_TYPE_P (TREE_TYPE (size)))
@@ -6427,6 +6428,7 @@ grokdeclarator (const struct c_declarator *declarator,
 		      error_at (loc, "size of unnamed array has incomplete "
 				"type");
 		    size = integer_one_node;
+		    size_int_const = true;
 		  }
 
 		size = c_fully_fold (size, false, &size_maybe_const);
@@ -6451,6 +6453,7 @@ grokdeclarator (const struct c_declarator *declarator,
 			else
 			  error_at (loc, "size of unnamed array is negative");
 			size = integer_one_node;
+			size_int_const = true;
 		      }
 		    /* Handle a size folded to an integer constant but
 		       not an integer constant expression.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3e51175368c..6c3cb701626 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,9 @@
 2020-03-28  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c/93573
+	* gcc.dg/pr93573-1.c: New test.
+	* gcc.dg/pr93573-2.c: New test.
+
 	PR tree-optimization/94329
 	* gfortran.dg/pr94329.f90: New test.
 
diff --git a/gcc/testsuite/gcc.dg/pr93573-1.c b/gcc/testsuite/gcc.dg/pr93573-1.c
new file mode 100644
index 00000000000..26ec9b77d6f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr93573-1.c
@@ -0,0 +1,12 @@
+/* PR c/93573 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void bar ();
+
+void
+foo (char a)
+{
+  union C { int d[100.0]; char *e; };	/* { dg-error "has non-integer type" } */
+  bar ((union C) &a);
+}
diff --git a/gcc/testsuite/gcc.dg/pr93573-2.c b/gcc/testsuite/gcc.dg/pr93573-2.c
new file mode 100644
index 00000000000..f8809453b4c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr93573-2.c
@@ -0,0 +1,6 @@
+/* PR c/93573 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+int f[100.0];	/* { dg-error "has non-integer type" } */
+                /* { dg-bogus "variably modified .f. at file scope" "" { target *-*-* } .-1 } */