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[PATCH] PR fortran/67939 -- Fix zero length strings in DATA statement
- From: Steve Kargl <sgk at troutmask dot apl dot washington dot edu>
- To: fortran at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Wed, 21 Oct 2015 13:05:58 -0700
- Subject: [PATCH] PR fortran/67939 -- Fix zero length strings in DATA statement
- Authentication-results: sourceware.org; auth=none
The attach patch properly sets the length for a zero length string
in a data. Built and regression tested on x86_64-*-freebsd. The
testcase is self-explanatory.
OK to commit?
2015-10-21 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/67939
* data.c (create_character_initializer): Deal with zero length string.
2015-10-21 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/67939
* gfortran.dg/pr67939.f90: New test.
--
Steve
Index: gcc/fortran/data.c
===================================================================
--- gcc/fortran/data.c (revision 229138)
+++ gcc/fortran/data.c (working copy)
@@ -104,7 +104,7 @@ static gfc_expr *
create_character_initializer (gfc_expr *init, gfc_typespec *ts,
gfc_ref *ref, gfc_expr *rvalue)
{
- int len, start, end;
+ int len, start, end, tlen;
gfc_char_t *dest;
bool alloced_init = false;
@@ -162,12 +162,22 @@ create_character_initializer (gfc_expr *
else
len = rvalue->value.character.length;
- if (len > end - start)
+ tlen = end - start;
+ if (len > tlen)
{
- gfc_warning_now (0, "Initialization string starting at %L was "
- "truncated to fit the variable (%d/%d)",
- &rvalue->where, end - start, len);
- len = end - start;
+ if (tlen < 0)
+ {
+ gfc_warning_now (0, "Unused initialization string at %L because "
+ "variable has zero length", &rvalue->where);
+ len = 0;
+ }
+ else
+ {
+ gfc_warning_now (0, "Initialization string at %L was truncated to "
+ "fit the variable (%d/%d)", &rvalue->where,
+ tlen, len);
+ len = tlen;
+ }
}
if (rvalue->ts.type == BT_HOLLERITH)
@@ -181,7 +191,7 @@ create_character_initializer (gfc_expr *
len * sizeof (gfc_char_t));
/* Pad with spaces. Substrings will already be blanked. */
- if (len < end - start && ref == NULL)
+ if (len < tlen && ref == NULL)
gfc_wide_memset (&dest[start + len], ' ', end - (start + len));
if (rvalue->ts.type == BT_HOLLERITH)
Index: gcc/testsuite/gfortran.dg/pr67939.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr67939.f90 (revision 0)
+++ gcc/testsuite/gfortran.dg/pr67939.f90 (working copy)
@@ -0,0 +1,21 @@
+! { dg-do compile }
+! PR fortran/67939
+! Original code by Gerhard Steinmetz
+! gerhard dot steinmetz dot fortran at t-online dot de
+!
+program p
+ character(100) :: x
+ data x(998:99) /'ab'/ ! { dg-warning "Unused initialization string" }
+ call a
+end
+
+subroutine a
+ character(2) :: x
+ data x(:-1) /'ab'/ ! { dg-warning "Unused initialization string" }
+end subroutine a
+
+subroutine b
+ character(8) :: x
+ data x(3:1) /'abc'/ ! { dg-warning "Unused initialization string" }
+end subroutine b
+