An earlier version of the attached patch lingered in bugzilla for over 3 years. I've updated the patch to include Manuel's comment #12. Regression tested on x86_64-*-freebsd. OK to commit?
2016-11-16 Steven G. Kargl <ka...@gcc.gnu.org> PR fortran/58001 * io.c (next_char_not_space): Update handling of a 'tab' in a FORMAT. (format_lex): Adjust invocations of next_char_not_space(). 2016-11-16 Steven G. Kargl <ka...@gcc.gnu.org> PR fortran/58001 * gfortran.dg/fmt_tab_1.f90: Adjust testcase. * gfortran.dg/fmt_tab_2.f90: Ditto. -- Steve
Index: gcc/fortran/io.c =================================================================== --- gcc/fortran/io.c (revision 242512) +++ gcc/fortran/io.c (working copy) @@ -200,23 +200,14 @@ unget_char (void) /* Eat up the spaces and return a character. */ static char -next_char_not_space (bool *error) +next_char_not_space () { char c; do { error_element = c = next_char (NONSTRING); if (c == '\t') - { - if (gfc_option.allow_std & GFC_STD_GNU) - gfc_warning (0, "Extension: Tab character in format at %C"); - else - { - gfc_error ("Extension: Tab character in format at %C"); - *error = true; - return c; - } - } + gfc_warning (OPT_Wtabs, "Nonconforming tab character in format at %C"); } while (gfc_is_whitespace (c)); return c; @@ -234,7 +225,6 @@ format_lex (void) char c, delim; int zflag; int negative_flag; - bool error = false; if (saved_token != FMT_NONE) { @@ -243,7 +233,7 @@ format_lex (void) return token; } - c = next_char_not_space (&error); + c = next_char_not_space (); negative_flag = 0; switch (c) @@ -253,7 +243,7 @@ format_lex (void) /* Falls through. */ case '+': - c = next_char_not_space (&error); + c = next_char_not_space (); if (!ISDIGIT (c)) { token = FMT_UNKNOWN; @@ -264,7 +254,7 @@ format_lex (void) do { - c = next_char_not_space (&error); + c = next_char_not_space (); if (ISDIGIT (c)) value = 10 * value + c - '0'; } @@ -294,7 +284,7 @@ format_lex (void) do { - c = next_char_not_space (&error); + c = next_char_not_space (); if (ISDIGIT (c)) { value = 10 * value + c - '0'; @@ -329,7 +319,7 @@ format_lex (void) break; case 'T': - c = next_char_not_space (&error); + c = next_char_not_space (); switch (c) { case 'L': @@ -357,7 +347,7 @@ format_lex (void) break; case 'S': - c = next_char_not_space (&error); + c = next_char_not_space (); if (c != 'P' && c != 'S') unget_char (); @@ -365,7 +355,7 @@ format_lex (void) break; case 'B': - c = next_char_not_space (&error); + c = next_char_not_space (); if (c == 'N' || c == 'Z') token = FMT_BLANK; else @@ -427,7 +417,7 @@ format_lex (void) break; case 'E': - c = next_char_not_space (&error); + c = next_char_not_space (); if (c == 'N' ) token = FMT_EN; else if (c == 'S') @@ -457,7 +447,7 @@ format_lex (void) break; case 'D': - c = next_char_not_space (&error); + c = next_char_not_space (); if (c == 'P') { if (!gfc_notify_std (GFC_STD_F2003, "DP format " @@ -478,7 +468,7 @@ format_lex (void) "specifier not allowed at %C")) return FMT_ERROR; token = FMT_DT; - c = next_char_not_space (&error); + c = next_char_not_space (); if (c == '\'' || c == '"') { delim = c; @@ -518,7 +508,7 @@ format_lex (void) break; case 'R': - c = next_char_not_space (&error); + c = next_char_not_space (); switch (c) { case 'C': @@ -559,9 +549,6 @@ format_lex (void) break; } - if (error) - return FMT_ERROR; - return token; } Index: gcc/testsuite/gfortran.dg/fmt_tab_1.f90 =================================================================== --- gcc/testsuite/gfortran.dg/fmt_tab_1.f90 (revision 242512) +++ gcc/testsuite/gfortran.dg/fmt_tab_1.f90 (working copy) @@ -1,7 +1,12 @@ ! { dg-do compile } -! { dg-options -Wno-error=tabs } +! { dg-options -Wtabs } ! PR fortran/32987 +! PR fortran/58001 program TestFormat write (*, 10) - 10 format ('Hello ', 'bug!') ! { dg-warning "Extension: Tab character in format" } + ! There is a tab character before 'bug!'. This is accepted without + ! the -Wno-tabs option or a -std= option. + 10 format ('Hello ', 'bug!') ! { dg-warning "tab character in format" } + end +! { dg-excess-errors "tab character in format" } Index: gcc/testsuite/gfortran.dg/fmt_tab_2.f90 =================================================================== --- gcc/testsuite/gfortran.dg/fmt_tab_2.f90 (revision 242512) +++ gcc/testsuite/gfortran.dg/fmt_tab_2.f90 (working copy) @@ -1,7 +1,9 @@ ! { dg-do compile } ! { dg-options "-std=f2003" } ! PR fortran/32987 +! PR fortran/58001 program TestFormat - write (*, 10) ! { dg-error "FORMAT label 10 at .1. not defined" } - 10 format ('Hello ', 'bug!') ! { dg-error "Extension: Tab character in format|Nonconforming tab character" } + write (*, 10) + 10 format ('Hello ', 'bug!') ! { dg-warning "tab character in format" } end +! { dg-excess-errors "tab character in FORMAT" }