diff options
| -rw-r--r-- | gcc/f/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/f/com.c | 48 | ||||
| -rw-r--r-- | gcc/f/news.texi | 10 |
3 files changed, 55 insertions, 10 deletions
diff --git a/gcc/f/ChangeLog b/gcc/f/ChangeLog index 666001dff23..df0595c8440 100644 --- a/gcc/f/ChangeLog +++ b/gcc/f/ChangeLog @@ -1,3 +1,10 @@ +Thu Sep 20 15:05:20 JST 2001 George Helffrich <george@geo.titech.ac.jp> + + * com.c (ffecom_subscript_check_): Loosen subscript checking rules + for character strings, to permit substring expressions like + string(1:0). + * news.texi: Document this as a new feature. + Thu Sep 13 10:33:27 2001 Kaveh R. Ghazi <ghazi@caip.rutgers.edu> * bad.c (ffebad_finish): Const-ification and/or static-ization. diff --git a/gcc/f/com.c b/gcc/f/com.c index bdf3e7cee76..8d9ad8c217a 100644 --- a/gcc/f/com.c +++ b/gcc/f/com.c @@ -671,16 +671,46 @@ ffecom_subscript_check_ (tree array, tree element, int dim, int total_dims, } element = ffecom_save_tree (element); - cond = ffecom_2 (LE_EXPR, integer_type_node, - low, - element); - if (high) + if (total_dims == 0) { - cond = ffecom_2 (TRUTH_ANDIF_EXPR, integer_type_node, - cond, - ffecom_2 (LE_EXPR, integer_type_node, - element, - high)); + /* Special handling for substring range checks. Fortran allows the + end subscript < begin subscript, which means that expressions like + string(1:0) are valid (and yield a null string). In view of this, + enforce two simpler conditions: + 1) element<=high for end-substring; + 2) element>=low for start-substring. + Run-time character movement will enforce remaining conditions. + + More complicated checks would be better, but present structure only + provides one index element at a time, so it is not possible to + enforce a check of both i and j in string(i:j). If it were, the + complete set of rules would read, + if ( ((j<i) && ((low<=i<=high) || (low<=j<=high))) || + ((low<=i<=high) && (low<=j<=high)) ) + ok ; + else + range error ; + */ + if (dim) + cond = ffecom_2 (LE_EXPR, integer_type_node, element, high); + else + cond = ffecom_2 (LE_EXPR, integer_type_node, low, element); + } + else + { + /* Array reference substring range checking. */ + + cond = ffecom_2 (LE_EXPR, integer_type_node, + low, + element); + if (high) + { + cond = ffecom_2 (TRUTH_ANDIF_EXPR, integer_type_node, + cond, + ffecom_2 (LE_EXPR, integer_type_node, + element, + high)); + } } { diff --git a/gcc/f/news.texi b/gcc/f/news.texi index 992ba28a8cf..82a94b3a994 100644 --- a/gcc/f/news.texi +++ b/gcc/f/news.texi @@ -156,7 +156,15 @@ The following information was last updated on @value{last-update-news}: @itemize @bullet @ifclear USERVISONLY @item -[ Nothing yet ] +George Helffrich (@email{george@@geo.titech.ac.jp}) implemented a change +in substring index checking (when specifying @code{-fbounds-check}) +that permits the use of zero length substrings of the form +@code{string(1:0)}. + +@item +Based on code developed by Pedro Vazquez (@email{vazquez@@penelope.iqm.unicamp.br}), +the @code{libf2c} library is now able to read and write files larger than +2 Gbyte on 32-bit target machines, if the operating system supports this. @end ifclear @end itemize |
