Am 13.12.20 um 20:59 schrieb Iain Sandoe via Fortran:
For bonus points you can prefix with _GFC_ which puts the symbols
in the implementation’s namespace (at least for C-Family purposes)
and therefore means that a clash with a user’s symbols is the user’s
problem …
I don't think this is necessary. Specifying uppercase letters is
already a technical impossibility, we don't need to add convention
to it as well :-)
After reading some tree dumps, I have also now come to the conclusion
that adding GFC_ to everything makes for poor reading. In the
version I have committed as r11-6087, I have now capitalized
all prefixes, if present, and used GFC_ otherweise.
Just one more remark: This version lets you set a watchpoint on
num_var so you can easily stop if a certain variable is generated.
That also helps :-)
Best regards, and thanks again for the comments.
Thomas
Add the -fdebug-aux-vars flag to debug variables generated by Fortran.
gcc/fortran/ChangeLog:
PR fortran/90207
* invoke.texi: Document -fdebug-aux-vars.
* lang.opt: Add -fdebug-aux-vars.
* trans.c (MAX_PREFIX_LEN): New macro.
(create_var_debug_raw): New function.
(gfc_create_var_np): Call create_var_debug_raw if
flag_debug_aux_vars is set.
diff --git a/gcc/fortran/invoke.texi b/gcc/fortran/invoke.texi
index 8bdc8a6b038..069ccd339f3 100644
--- a/gcc/fortran/invoke.texi
+++ b/gcc/fortran/invoke.texi
@@ -160,7 +160,7 @@ and warnings}.
@item Debugging Options
@xref{Debugging Options,,Options for debugging your program or GNU Fortran}.
@gccoptlist{-fbacktrace -fdump-fortran-optimized -fdump-fortran-original @gol
--fdump-fortran-global -fdump-parse-tree -ffpe-trap=@var{list} @gol
+-fdebug-aux-vars -fdump-fortran-global -fdump-parse-tree -ffpe-trap=@var{list} @gol
-ffpe-summary=@var{list}
}
@@ -1219,6 +1219,15 @@ change between releases. This option may also generate internal
compiler errors for features which have only recently been added. This
option is deprecated; use @code{-fdump-fortran-original} instead.
+@item -fdebug-aux-vars
+@opindex @code{fdebug-aux-vars}
+Renames internal variables created by the gfortran front end and makes
+them accessible to a debugger. The name of the internal variables then
+start with upper-case letters followed by an underscore. This option is
+useful for debugging the compiler's code generation together with
+@code{-fdump-tree-original} and enabling debugging of the executable
+program by using @code{-g} or @code{-ggdb3}.
+
@item -fdump-fortran-global
@opindex @code{fdump-fortran-global}
Output a list of the global identifiers after translating into
diff --git a/gcc/fortran/lang.opt b/gcc/fortran/lang.opt
index 96ed208cb85..57b0264458e 100644
--- a/gcc/fortran/lang.opt
+++ b/gcc/fortran/lang.opt
@@ -452,6 +452,10 @@ fd-lines-as-comments
Fortran RejectNegative
Treat lines with 'D' in column one as comments.
+fdebug-aux-vars
+Fortran Var(flag_debug_aux_vars)
+Issue debug information for compiler-generated auxiliary variables.
+
fdec
Fortran Var(flag_dec)
Enable all DEC language extensions.
diff --git a/gcc/fortran/trans.c b/gcc/fortran/trans.c
index 025abe38985..ca0b10ca73d 100644
--- a/gcc/fortran/trans.c
+++ b/gcc/fortran/trans.c
@@ -73,6 +73,45 @@ gfc_advance_chain (tree t, int n)
return t;
}
+static int num_var;
+
+#define MAX_PREFIX_LEN 20
+
+static tree
+create_var_debug_raw (tree type, const char *prefix)
+{
+ /* Space for prefix + "_" + 10-digit-number + \0. */
+ char name_buf[MAX_PREFIX_LEN + 1 + 10 + 1];
+ tree t;
+ int i;
+
+ if (prefix == NULL)
+ prefix = "gfc";
+ else
+ gcc_assert (strlen (prefix) <= MAX_PREFIX_LEN);
+
+ for (i = 0; prefix[i] != 0; i++)
+ name_buf[i] = gfc_wide_toupper (prefix[i]);
+
+ snprintf (name_buf + i, sizeof (name_buf) - i, "_%d", num_var++);
+
+ t = build_decl (input_location, VAR_DECL, get_identifier (name_buf), type);
+
+ /* We want debug info for it. */
+ DECL_IGNORED_P (t) = 0;
+ /* It should not be nameless. */
+ DECL_NAMELESS (t) = 0;
+
+ /* Make the variable writable. */
+ TREE_READONLY (t) = 0;
+
+ DECL_EXTERNAL (t) = 0;
+ TREE_STATIC (t) = 0;
+ TREE_USED (t) = 1;
+
+ return t;
+}
+
/* Creates a variable declaration with a given TYPE. */
tree
@@ -80,6 +119,9 @@ gfc_create_var_np (tree type, const char *prefix)
{
tree t;
+ if (flag_debug_aux_vars)
+ return create_var_debug_raw (type, prefix);
+
t = create_tmp_var_raw (type, prefix);
/* No warnings for anonymous variables. */
