https://gcc.gnu.org/g:56902d171735f085dac88417b9ae8c72b7ab78fa
commit r16-4052-g56902d171735f085dac88417b9ae8c72b7ab78fa
Author: Gary Dismukes <dismu...@adacore.com>
Date: Wed Sep 10 19:33:56 2025 +0000
ada: New preprocessing option for emitting empty comments for deleted lines
When integrated preprocessing is done on a source file with lines that are
filtered out, by default this can result in multiple blank lines being
emitted,
but this can clash with the style switch -gnatyu, which will flag cases of
multiple blank lines. A new preprocessing option "-e" is added to allow
outputting "empty" comment lines rather than blank lines (the comments
consist
of "--!" and no other text). This option is also available for the gnatprep
tool. This behavior is the default when integrated preprocessing is done
without generating a ".prep" output file with -gnateG, but when -gnateG is
used, blank lines are still substituted by default for directives and
removed
source lines (for compatibility with long-existing behavior). The -gnateG
switch is also extended to allow appending 'b', 'c', or 'e' at the end of
the switch to force any of the replacement options ('b' => blank lines,
'c' => comments including the original source lintes, and 'e' => empty
comment lines).
gcc/ada/ChangeLog:
* doc/gnat_ugn/building_executable_programs_with_gnat.rst: Add doc
for addition of -gnateG options b, c, and e.
* doc/gnat_ugn/the_gnat_compilation_model.rst: Add doc for "-e"
optionn
on gnatprep and integrated preprocessing. Add doc for addition of
-gnateG options b, c, and e.
* gprep.adb (Scan_Command_Line): Add 'e' to the list of allowed
switch
letters in the string passed to GNAT.Command_Line.Getopt. Set the
flag
Opt.Empty_Comment_Deleted_Lines to True when the "-e" switch is
found.
(Usage): Output a switch description for the "-e" switch.
* opt.ads: Add new flag variable Empty_Comment_Deleted_Lines. Add
"GNAT" to the "GNATPREP" comment line for Comment_Deleted_Lines.
* prep.adb (Output_Line): Add handling for
Empty_Comment_Deleted_Lines,
outputting comment lines consisting of "--!" for lines that are
removed
in the preprocessed source file when Empty_Comment_Deleted_Lines is
True.
* prepcomp.adb (Preproc_Data): Add Empty_Comments component
(defaulting
to False).
(No_Preproc_Data): Add association for Empty_Comments component.
(Parse_Preprocessing_Data_File): Add handling for new switch -e.
(Prepare_To_Preprocess): Add logic for setting the new option
Empty_Comment_Deleted_Lines (and making it the default for
integrated preprocessing in the absence of other switches).
* switch-c.adb (Scan_Front_End_Switches): Add support adding a
single
character 'b', 'c', 'e' to the "-gnateG" switch, to select any of
the
three options for replacing deleted lines in preprocessing output
file.
* usage.adb: Update usage info for -gnateG, to reflect the option of
appending b, c, or e to the switch.
* gnat_ugn.texi: Regenerate.
Diff:
---
.../building_executable_programs_with_gnat.rst | 8 ++-
.../doc/gnat_ugn/the_gnat_compilation_model.rst | 29 +++++++-
gcc/ada/gnat_ugn.texi | 48 +++++++++++--
gcc/ada/gprep.adb | 6 +-
gcc/ada/opt.ads | 7 +-
gcc/ada/prep.adb | 7 ++
gcc/ada/prepcomp.adb | 78 +++++++++++++++-------
gcc/ada/switch-c.adb | 40 +++++++++++
gcc/ada/usage.adb | 4 +-
9 files changed, 191 insertions(+), 36 deletions(-)
diff --git a/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
b/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
index fbd3202c3d65..b46f69b7d4a0 100644
--- a/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
+++ b/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
@@ -1608,8 +1608,12 @@ Alphabetical List of All Switches
.. index:: -gnateG (gcc)
-:switch:`-gnateG`
- Save result of preprocessing in a text file.
+:switch:`-gnateG[bce]`
+ Save result of preprocessing in a text file. An optional character (b, c,
+ or e) can be appended to indicate that filtered lines are to be replaced by
+ blank lines, comment lines that include the filtered line, or empty comment
+ lines ("--!"), respectively. The default is to replace filtered lines with
+ blank lines.
.. index:: -gnateH (gcc)
diff --git a/gcc/ada/doc/gnat_ugn/the_gnat_compilation_model.rst
b/gcc/ada/doc/gnat_ugn/the_gnat_compilation_model.rst
index 891886b53601..94b41b52adf2 100644
--- a/gcc/ada/doc/gnat_ugn/the_gnat_compilation_model.rst
+++ b/gcc/ada/doc/gnat_ugn/the_gnat_compilation_model.rst
@@ -2931,6 +2931,18 @@ Switches for ``gnatprep``
don't specify a value, the symbol is defined to be ``True``. You can
use this switch instead of providing a definition file.
+.. index:: -e (gnatprep)
+
+:switch:`-e`
+ Causes both preprocessor lines and the lines deleted by
+ preprocessing to be replaced by empty comment lines marked
+ with ``"--!"`` (and no other text) in the output source file,
+ preserving line numbers in the output file. This option can
+ be useful as an alternative to :switch:`-b` and :switch:`-c`
+ when compilation style switches like :switch:`-gnatyu` or
+ :switch:`-gnatyM` are used (to avoid warnings about multiple
+ blank lines or lines too long).
+
.. index:: -r (gnatprep)
:switch:`-r`
@@ -3248,7 +3260,7 @@ that relate to integrated preprocessing.
Causes both preprocessor lines and the lines deleted by
preprocessing to be replaced by blank lines, preserving the line number.
This switch is always implied; however, if specified after :switch:`-c`
- it cancels the effect of :switch:`-c`.
+ or :switch:`-e` it cancels the effect of those switches.
:switch:`-c`
Causes both preprocessor lines and the lines deleted
@@ -3266,6 +3278,12 @@ that relate to integrated preprocessing.
name defined in a definition file.
+ :switch:`-e`
+ Causes both preprocessor lines and the lines deleted by
+ preprocessing to be replaced by empty comment lines marked
+ with '`--!`' (and no other text) in the output source file,
+
+
:switch:`-s`
Causes a sorted list of symbol names and values to be
listed on the standard output file.
@@ -3306,12 +3324,19 @@ that relate to integrated preprocessing.
This switch is similar to switch :switch:`-D` of ``gnatprep``.
-:switch:`-gnateG`
+.. index:: -gnateG (gcc)
+
+:switch:`-gnateG[bce]`
When integrated preprocessing is performed on source file
:file:`filename.extension`,
create or overwrite :file:`filename.extension.prep` to contain
the result of the preprocessing.
For example if the source file is :file:`foo.adb` then
the output file is :file:`foo.adb.prep`.
+ An optional character (b, c, or e) can be appended to indicate that filtered
+ lines are to be replaced by blank lines, comments, or empty comments (see
+ documentation above about :switch:`-b`, :switch:`-c`, and :switch:`-e`).
+ If one of those switches is given in a preprocessor data file, then it
+ will override any option included with :switch:`-gnateG`.
.. _Mixed_Language_Programming:
diff --git a/gcc/ada/gnat_ugn.texi b/gcc/ada/gnat_ugn.texi
index 79b58d341ac8..e0771eb16b37 100644
--- a/gcc/ada/gnat_ugn.texi
+++ b/gcc/ada/gnat_ugn.texi
@@ -4628,6 +4628,23 @@ don’t specify a value, the symbol is defined to be
@code{True}. You can
use this switch instead of providing a definition file.
@end table
+@geindex -e (gnatprep)
+
+
+@table @asis
+
+@item @code{-e}
+
+Causes both preprocessor lines and the lines deleted by
+preprocessing to be replaced by empty comment lines marked
+with @code{"--!"} (and no other text) in the output source file,
+preserving line numbers in the output file. This option can
+be useful as an alternative to @code{-b} and @code{-c}
+when compilation style switches like @code{-gnatyu} or
+@code{-gnatyM} are used (to avoid warnings about multiple
+blank lines or lines too long).
+@end table
+
@geindex -r (gnatprep)
@@ -5023,7 +5040,7 @@ Finally, switches similar to those of @code{gnatprep} may
optionally appear:
Causes both preprocessor lines and the lines deleted by
preprocessing to be replaced by blank lines, preserving the line number.
This switch is always implied; however, if specified after @code{-c}
-it cancels the effect of @code{-c}.
+or @code{-e} it cancels the effect of those switches.
@item @code{-c}
@@ -5041,6 +5058,12 @@ literal string, an Ada identifier or any Ada reserved
word. A
symbol declared with this switch replaces a symbol with the same
name defined in a definition file.
+@item @code{-e}
+
+Causes both preprocessor lines and the lines deleted by
+preprocessing to be replaced by empty comment lines marked
+with ‘@cite{–!}’ (and no other text) in the output source file,
+
@item @code{-s}
Causes a sorted list of symbol names and values to be
@@ -5088,14 +5111,25 @@ symbol with the same name either in a definition file
or specified with a
switch @code{-D} in the preprocessor data file.
This switch is similar to switch @code{-D} of @code{gnatprep}.
+@end table
+
+@geindex -gnateG (gcc)
-@item @code{-gnateG}
+
+@table @asis
+
+@item @code{-gnateG[bce]}
When integrated preprocessing is performed on source file
@code{filename.extension},
create or overwrite @code{filename.extension.prep} to contain
the result of the preprocessing.
For example if the source file is @code{foo.adb} then
the output file is @code{foo.adb.prep}.
+An optional character (b, c, or e) can be appended to indicate that filtered
+lines are to be replaced by blank lines, comments, or empty comments (see
+documentation above about @code{-b}, @code{-c}, and @code{-e}).
+If one of those switches is given in a preprocessor data file, then it
+will override any option included with @code{-gnateG}.
@end table
@node Mixed Language Programming,GNAT and Other Compilation Models,Conditional
Compilation,The GNAT Compilation Model
@@ -9155,9 +9189,13 @@ information.
@table @asis
-@item @code{-gnateG}
+@item @code{-gnateG[bce]}
-Save result of preprocessing in a text file.
+Save result of preprocessing in a text file. An optional character (b, c,
+or e) can be appended to indicate that filtered lines are to be replaced by
+blank lines, comment lines that include the filtered line, or empty comment
+lines (”–!”), respectively. The default is to replace filtered lines with
+blank lines.
@end table
@geindex -gnateH (gcc)
@@ -30295,8 +30333,8 @@ to permit their use in free software.
@printindex ge
-@anchor{d2}@w{ }
@anchor{gnat_ugn/gnat_utility_programs switches-related-to-project-files}@w{
}
+@anchor{d2}@w{ }
@c %**end of body
@bye
diff --git a/gcc/ada/gprep.adb b/gcc/ada/gprep.adb
index 98e0072401e2..f40c38d8b145 100644
--- a/gcc/ada/gprep.adb
+++ b/gcc/ada/gprep.adb
@@ -735,7 +735,7 @@ package body GPrep is
loop
begin
- Switch := GNAT.Command_Line.Getopt ("D: a b c C r s T u v");
+ Switch := GNAT.Command_Line.Getopt ("D: a b c C e r s T u v");
case Switch is
when ASCII.NUL =>
@@ -755,6 +755,9 @@ package body GPrep is
when 'c' =>
Opt.Comment_Deleted_Lines := True;
+ when 'e' =>
+ Opt.Empty_Comment_Deleted_Lines := True;
+
when 'C' =>
Opt.Replace_In_Comments := True;
@@ -831,6 +834,7 @@ package body GPrep is
Write_Line (" -c Keep preprocessor lines as comments");
Write_Line (" -C Do symbol replacements within comments");
Write_Line (" -D Associate symbol with value");
+ Write_Line (" -e Replace preprocessor lines by empty comment lines");
Write_Line (" -r Generate Source_Reference pragma");
Write_Line (" -s Print a sorted list of symbol names and values");
Write_Line (" -T Use LF as line terminators");
diff --git a/gcc/ada/opt.ads b/gcc/ada/opt.ads
index ea3390e2b482..0fd5475e1279 100644
--- a/gcc/ada/opt.ads
+++ b/gcc/ada/opt.ads
@@ -338,7 +338,7 @@ package Opt is
-- True if echoed commands to be written to stdout instead of stderr
Comment_Deleted_Lines : Boolean := False;
- -- GNATPREP
+ -- GNAT, GNATPREP
-- True if source lines removed by the preprocessor should be commented
-- in the output file.
@@ -509,6 +509,11 @@ package Opt is
-- GNATBIND
-- Set to True to output chosen elaboration order
+ Empty_Comment_Deleted_Lines : Boolean := False;
+ -- GNAT, GNATPREP
+ -- True if source lines removed by the preprocessor are to be replaced
+ -- by empty comment lines ("--!" and no other text) in the output file.
+
Enable_128bit_Types : Boolean := False;
-- GNAT
-- Set to True to enable the support for 128-bit types in the compiler.
diff --git a/gcc/ada/prep.adb b/gcc/ada/prep.adb
index 951719e2cdf8..7e58421b56f3 100644
--- a/gcc/ada/prep.adb
+++ b/gcc/ada/prep.adb
@@ -1210,6 +1210,13 @@ package body Prep is
Output (From, To);
end if;
+ New_EOL.all;
+
+ elsif Empty_Comment_Deleted_Lines then
+ Put_Char ('-');
+ Put_Char ('-');
+ Put_Char ('!');
+
New_EOL.all;
end if;
diff --git a/gcc/ada/prepcomp.adb b/gcc/ada/prepcomp.adb
index 35dd4cbf53ae..f5ef40a0ff95 100644
--- a/gcc/ada/prepcomp.adb
+++ b/gcc/ada/prepcomp.adb
@@ -54,29 +54,31 @@ package body Prepcomp is
pragma Warnings (On);
type Preproc_Data is record
- Mapping : Symbol_Table.Instance;
- File_Name : File_Name_Type := No_File;
- Deffile : String_Id := No_String;
- Undef_False : Boolean := False;
- Always_Blank : Boolean := False;
- Comments : Boolean := False;
- No_Deletion : Boolean := False;
- List_Symbols : Boolean := False;
- Processed : Boolean := False;
+ Mapping : Symbol_Table.Instance;
+ File_Name : File_Name_Type := No_File;
+ Deffile : String_Id := No_String;
+ Undef_False : Boolean := False;
+ Always_Blank : Boolean := False;
+ Comments : Boolean := False;
+ Empty_Comments : Boolean := False;
+ No_Deletion : Boolean := False;
+ List_Symbols : Boolean := False;
+ Processed : Boolean := False;
end record;
-- Structure to keep the preprocessing data for a file name or for the
-- default (when Name_Id = No_Name).
No_Preproc_Data : constant Preproc_Data :=
- (Mapping => No_Mapping,
- File_Name => No_File,
- Deffile => No_String,
- Undef_False => False,
- Always_Blank => False,
- Comments => False,
- No_Deletion => False,
- List_Symbols => False,
- Processed => False);
+ (Mapping => No_Mapping,
+ File_Name => No_File,
+ Deffile => No_String,
+ Undef_False => False,
+ Always_Blank => False,
+ Comments => False,
+ Empty_Comments => False,
+ No_Deletion => False,
+ List_Symbols => False,
+ Processed => False);
Default_Data : Preproc_Data := No_Preproc_Data;
-- The preprocessing data to be used when no specific preprocessing data
@@ -170,6 +172,17 @@ package body Prepcomp is
No_Preprocessing := False;
Current_Data.Processed := True;
+ if Opt.Blank_Deleted_Lines then
+ Current_Data.Always_Blank := True;
+
+ elsif Opt.Comment_Deleted_Lines then
+ Current_Data.Comments := True;
+
+ elsif Opt.Empty_Comment_Deleted_Lines then
+ Current_Data.Empty_Comments := True;
+
+ end if;
+
-- Start with an empty, initialized mapping table; use Prep.Mapping,
-- because Prep.Index_Of uses Prep.Mapping.
@@ -379,6 +392,15 @@ package body Prepcomp is
OK := True;
end if;
+ when 'e' =>
+
+ -- Replace removed lines with empty comment lines ("--!")
+
+ if Name_Len = 1 then
+ Current_Data.Empty_Comments := True;
+ OK := True;
+ end if;
+
when 's' =>
-- List symbols
@@ -601,12 +623,22 @@ package body Prepcomp is
-- Set the preprocessing flags according to the preprocessing data
- if Current_Data.Comments and not Current_Data.Always_Blank then
- Comment_Deleted_Lines := True;
- Blank_Deleted_Lines := False;
+ if Current_Data.Comments then
+ Comment_Deleted_Lines := True;
+ Empty_Comment_Deleted_Lines := False;
+ Blank_Deleted_Lines := False;
+
+ elsif Current_Data.Always_Blank then
+ Comment_Deleted_Lines := False;
+ Empty_Comment_Deleted_Lines := False;
+ Blank_Deleted_Lines := True;
+
+ -- By default, emit empty comment lines in place of deleted lines
+
else
- Comment_Deleted_Lines := False;
- Blank_Deleted_Lines := True;
+ Comment_Deleted_Lines := False;
+ Empty_Comment_Deleted_Lines := True;
+ Blank_Deleted_Lines := False;
end if;
No_Deletion := Current_Data.No_Deletion;
diff --git a/gcc/ada/switch-c.adb b/gcc/ada/switch-c.adb
index efad12c9c408..3b4375700c01 100644
--- a/gcc/ada/switch-c.adb
+++ b/gcc/ada/switch-c.adb
@@ -636,6 +636,46 @@ package body Switch.C is
Generate_Processed_File := True;
Ptr := Ptr + 1;
+ if Ptr <= Max
+ and then Switch_Chars (Ptr) in 'b' | 'c' | 'e'
+ then
+ case Switch_Chars (Ptr) is
+ when 'b' =>
+ Opt.Blank_Deleted_Lines := True;
+ Opt.Comment_Deleted_Lines := False;
+ Opt.Empty_Comment_Deleted_Lines := False;
+
+ when 'c' =>
+ Opt.Blank_Deleted_Lines := False;
+ Opt.Comment_Deleted_Lines := True;
+ Opt.Empty_Comment_Deleted_Lines := False;
+
+ when 'e' =>
+ Opt.Blank_Deleted_Lines := False;
+ Opt.Comment_Deleted_Lines := False;
+ Opt.Empty_Comment_Deleted_Lines := True;
+
+ when others =>
+ raise Program_Error;
+ end case;
+
+ Ptr := Ptr + 1;
+
+ -- Default to emitting blank lines for deleted lines
+ -- when generating a preprocessor output file. This is
+ -- despite the fact that when the file isn't being
+ -- generated, we emit empty comment lines for the
+ -- internally generated output (to avoid conflicts
+ -- with style switches -gnatyu and -gnatyM), but is
+ -- done for compatibility with the behavior of -gnateG
+ -- prior to adding support for empty comment lines.
+
+ else
+ Opt.Blank_Deleted_Lines := True;
+ Opt.Comment_Deleted_Lines := False;
+ Opt.Empty_Comment_Deleted_Lines := False;
+ end if;
+
-- -gnateH (set reverse Bit_Order threshold to 64)
when 'H' =>
diff --git a/gcc/ada/usage.adb b/gcc/ada/usage.adb
index 5b87bb54dcaa..e59f32448d17 100644
--- a/gcc/ada/usage.adb
+++ b/gcc/ada/usage.adb
@@ -196,8 +196,8 @@ begin
-- Line for -gnateG switch
- Write_Switch_Char ("eG");
- Write_Line ("Generate preprocessed source");
+ Write_Switch_Char ("eG[?]");
+ Write_Line ("Generate preprocessed source (?=b/c/e)");
-- Line for -gnateH switch
