[PATCH, v4] Fortran: detect blanks within literal constants in free-form mode [PR92805]

[Harald Anlauf <anlauf@gmx.de>]

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Hi Mikael,

Am 30.07.22 um 10:28 schrieb Mikael Morin:
> Meh! We killed one check for gfc_current_form but the other one is still
> there.
> OK, match_kind_param calls two functions that also gobble space, so
> there is work remaining here.
> So please make match_small_literal_constant and gfc_match_name
> space-gobbling wrappers around space-non-gobbling inner functions and
> call those inner functions instead in match_kind_param.

well, here's the shortest solution I could come up with.
I added a new argument to 3 functions used in parsing that
controls the gobbling of whitespace.  We use this to handle
whitespace for numerical literals, while the parsing of string
literals remains as in the previous version of the patch.

This version obviously ignores Thomas' request, as that would
require to treat gfc_match_char specially...

Regtested again.  OK now?

Thanks,
Harald

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From cb33d1d0b91b371a864379d920ddaefc15d587f9 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Thu, 28 Jul 2022 22:07:02 +0200
Subject: [PATCH] Fortran: detect blanks within literal constants in free-form
 mode [PR92805]

gcc/fortran/ChangeLog:

	PR fortran/92805
	* match.cc (gfc_match_small_literal_int): Make gobbling of leading
	whitespace optional.
	(gfc_match_name): Likewise.
	(gfc_match_char): Likewise.
	* match.h (gfc_match_small_literal_int): Adjust prototype.
	(gfc_match_name): Likewise.
	(gfc_match_char): Likewise.
	* primary.cc (match_kind_param): Match small literal int or name
	without gobbling whitespace.
	(get_kind): Do not skip over blanks in free-form mode.
	(match_string_constant): Likewise.

gcc/testsuite/ChangeLog:

	PR fortran/92805
	* gfortran.dg/literal_constants.f: New test.
	* gfortran.dg/literal_constants.f90: New test.

Co-authored-by: Steven G. Kargl <kargl@gcc.gnu.org>
---
 gcc/fortran/match.cc                          | 21 +++++++++-------
 gcc/fortran/match.h                           |  6 ++---
 gcc/fortran/primary.cc                        | 14 +++--------
 gcc/testsuite/gfortran.dg/literal_constants.f | 20 ++++++++++++++++
 .../gfortran.dg/literal_constants.f90         | 24 +++++++++++++++++++
 5 files changed, 63 insertions(+), 22 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/literal_constants.f
 create mode 100644 gcc/testsuite/gfortran.dg/literal_constants.f90

diff --git a/gcc/fortran/match.cc b/gcc/fortran/match.cc
index 1aa3053e70e..c0dc0e89361 100644
--- a/gcc/fortran/match.cc
+++ b/gcc/fortran/match.cc
@@ -457,7 +457,7 @@ gfc_match_eos (void)
    will be set to the number of digits.  */
 
 match
-gfc_match_small_literal_int (int *value, int *cnt)
+gfc_match_small_literal_int (int *value, int *cnt, bool gobble_ws)
 {
   locus old_loc;
   char c;
@@ -466,7 +466,8 @@ gfc_match_small_literal_int (int *value, int *cnt)
   old_loc = gfc_current_locus;
 
   *value = -1;
-  gfc_gobble_whitespace ();
+  if (gobble_ws)
+    gfc_gobble_whitespace ();
   c = gfc_next_ascii_char ();
   if (cnt)
     *cnt = 0;
@@ -611,14 +612,15 @@ gfc_match_label (void)
    than GFC_MAX_SYMBOL_LEN.  */
 
 match
-gfc_match_name (char *buffer)
+gfc_match_name (char *buffer, bool gobble_ws)
 {
   locus old_loc;
   int i;
   char c;
 
   old_loc = gfc_current_locus;
-  gfc_gobble_whitespace ();
+  if (gobble_ws)
+    gfc_gobble_whitespace ();
 
   c = gfc_next_ascii_char ();
   if (!(ISALPHA (c) || (c == '_' && flag_allow_leading_underscore)))
@@ -1052,16 +1054,19 @@ cleanup:
 }
 
 
-/* Tries to match the next non-whitespace character on the input.
-   This subroutine does not return MATCH_ERROR.  */
+/* Tries to match the next non-whitespace character on the input.  This
+   subroutine does not return MATCH_ERROR.  When gobble_ws is false, do not
+   skip over leading blanks.
+*/
 
 match
-gfc_match_char (char c)
+gfc_match_char (char c, bool gobble_ws)
 {
   locus where;
 
   where = gfc_current_locus;
-  gfc_gobble_whitespace ();
+  if (gobble_ws)
+    gfc_gobble_whitespace ();
 
   if (gfc_next_ascii_char () == c)
     return MATCH_YES;
diff --git a/gcc/fortran/match.h b/gcc/fortran/match.h
index 495c93e0b5c..1f53e0cb67d 100644
--- a/gcc/fortran/match.h
+++ b/gcc/fortran/match.h
@@ -45,14 +45,14 @@ extern gfc_access gfc_typebound_default_access;
 match gfc_match_special_char (gfc_char_t *);
 match gfc_match_space (void);
 match gfc_match_eos (void);
-match gfc_match_small_literal_int (int *, int *);
+match gfc_match_small_literal_int (int *, int *, bool = true);
 match gfc_match_st_label (gfc_st_label **);
 match gfc_match_small_int (int *);
-match gfc_match_name (char *);
+match gfc_match_name (char *, bool = true);
 match gfc_match_symbol (gfc_symbol **, int);
 match gfc_match_sym_tree (gfc_symtree **, int);
 match gfc_match_intrinsic_op (gfc_intrinsic_op *);
-match gfc_match_char (char);
+match gfc_match_char (char, bool = true);
 match gfc_match (const char *, ...);
 match gfc_match_iterator (gfc_iterator *, int);
 match gfc_match_parens (void);
diff --git a/gcc/fortran/primary.cc b/gcc/fortran/primary.cc
index 3f01f67cd49..19f2e78c8ff 100644
--- a/gcc/fortran/primary.cc
+++ b/gcc/fortran/primary.cc
@@ -45,11 +45,11 @@ match_kind_param (int *kind, int *is_iso_c)
 
   *is_iso_c = 0;
 
-  m = gfc_match_small_literal_int (kind, NULL);
+  m = gfc_match_small_literal_int (kind, NULL, false);
   if (m != MATCH_NO)
     return m;
 
-  m = gfc_match_name (name);
+  m = gfc_match_name (name, false);
   if (m != MATCH_YES)
     return m;
 
@@ -95,7 +95,7 @@ get_kind (int *is_iso_c)
 
   *is_iso_c = 0;
 
-  if (gfc_match_char ('_') != MATCH_YES)
+  if (gfc_match_char ('_', false) != MATCH_YES)
     return -2;
 
   m = match_kind_param (&kind, is_iso_c);
@@ -1074,17 +1074,9 @@ match_string_constant (gfc_expr **result)
       c = gfc_next_char ();
     }
 
-  if (c == ' ')
-    {
-      gfc_gobble_whitespace ();
-      c = gfc_next_char ();
-    }
-
   if (c != '_')
     goto no_match;
 
-  gfc_gobble_whitespace ();
-
   c = gfc_next_char ();
   if (c != '\'' && c != '"')
     goto no_match;
diff --git a/gcc/testsuite/gfortran.dg/literal_constants.f b/gcc/testsuite/gfortran.dg/literal_constants.f
new file mode 100644
index 00000000000..4d1f1b7eb4c
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/literal_constants.f
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! { dg-options "-ffixed-form" }
+! PR fortran/92805 - blanks within literal constants in fixed-form mode
+
+      implicit none
+      integer, parameter :: ck = kind ("a")  ! default character kind
+      integer, parameter :: rk = kind (1.0)  ! default real kind
+      print *, 1_"abc"
+      print *, 1 _"abc"
+      print *, 1_ "abc"
+      print *, ck_"a"
+      print *, ck _"ab"
+      print *, ck_ "ab"
+      print *, 3.1415_4
+      print *, 3.1415 _4
+      print *, 3.1415_ 4
+      print *, 3.1415_rk
+      print *, 3.1415 _rk
+      print *, 3.1415_ rk
+      end
diff --git a/gcc/testsuite/gfortran.dg/literal_constants.f90 b/gcc/testsuite/gfortran.dg/literal_constants.f90
new file mode 100644
index 00000000000..f8908f9ad76
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/literal_constants.f90
@@ -0,0 +1,24 @@
+! { dg-do compile }
+! { dg-options "-ffree-form" }
+! PR fortran/92805 - blanks within literal constants in free-form mode
+
+      implicit none
+      integer, parameter :: ck = kind ("a")  ! default character kind
+      integer, parameter :: rk = kind (1.0)  ! default real kind
+      print *, 1_"abc"
+      print *, 1 _"abc"   ! { dg-error "Syntax error" }
+      print *, 1_ "abc"   ! { dg-error "Missing kind-parameter" }
+      print *, 1 _ "abc"  ! { dg-error "Syntax error" }
+      print *, ck_"a"
+      print *, ck _"ab"   ! { dg-error "Syntax error" }
+      print *, ck_ "ab"   ! { dg-error "Syntax error" }
+      print *, ck _ "ab"  ! { dg-error "Syntax error" }
+      print *, 3.1415_4
+      print *, 3.1415 _4  ! { dg-error "Syntax error" }
+      print *, 3.1415_ 4  ! { dg-error "Missing kind-parameter" }
+      print *, 3.1415 _ 4 ! { dg-error "Syntax error" }
+      print *, 3.1415_rk
+      print *, 3.1415 _rk ! { dg-error "Syntax error" }
+      print *, 3.1415_ rk ! { dg-error "Missing kind-parameter" }
+      print *, 3.141 _ rk ! { dg-error "Syntax error" }
+      end
-- 
2.35.3