modula2: new option -Wcase-enum and associated fixes

This patch introduces -Wcase-enum which enumerates each missing
field in a case statement without an else clause providing the selector
expression type is an enum.

gcc/ChangeLog:

	* doc/gm2.texi (Compiler options): Document new option
	-Wcase-enum.

gcc/m2/ChangeLog:

	* gm2-compiler/M2CaseList.def (PushCase): Rename parameters
	r to rec and v to va.  Add expr parameter.
	(MissingCaseStatementBounds): New procedure function.
	* gm2-compiler/M2CaseList.mod (RangePair): Add expression.
	(PushCase): Rename parameters r to rec and v to va.  Add
	expr parameter.
	(RemoveRange): New procedure function.
	(SubBitRange): Detect the case when the range in the set matches
	lo..hi.
	(CheckLowHigh): New procedure.
	(ExcludeCaseRanges): Rename parameter c to cd.  Rename local
	variables q to cl and r to rp.
	(High): Remove.
	(Low): Remove.
	(DoEnumValues): Remove.
	(IncludeElement): New procedure.
	(IncludeElements): New procedure.
	(ErrorRangeEnum): New procedure.
	(ErrorRange): Remove.
	(ErrorRanges): Remove.
	(appendEnum): New procedure.
	(appendStr): New procedure.
	(EnumerateErrors): New procedure.
	(MissingCaseBounds): Re-implement.
	(InRangeList): Remove.
	(MissingCaseStatementBounds): New procedure function.
	(checkTypes): Re-format.
	(inRange): Re-format.
	(TypeCaseBounds): Re-format.
	* gm2-compiler/M2Error.mod (GetAnnounceScope): Add noscope to
	case label list.
	* gm2-compiler/M2GCCDeclare.mod: Replace ForeachFieldEnumerationDo
	with ForeachLocalSymDo.
	* gm2-compiler/M2Options.def (SetCaseEnumChecking): New procedure.
	(CaseEnumChecking): New variable.
	* gm2-compiler/M2Options.mod (SetCaseEnumChecking): New procedure.
	(Module initialization): set CaseEnumChecking to FALSE.
	* gm2-compiler/M2Quads.def (QuadOperator): Alphabetically ordered.
	* gm2-compiler/M2Quads.mod (IsBackReferenceConditional): Add else
	clause.
	(BuildCaseStart): Pass selector expression to InitCaseBounds.
	(CheckUninitializedVariablesAreUsed): Remove.
	(IsInlineWithinBlock): Remove.
	(AsmStatementsInBlock): Remove.
	(CheckVariablesInBlock): Remove commented code.
	(BeginVarient): Pass NulSym to InitCaseBounds.
	* gm2-compiler/M2Range.mod (FoldCaseBounds): New local variable
	errorGenerated.  Add call to MissingCaseStatementBounds.
	* gm2-compiler/P3Build.bnf (CaseEndStatement): Call ElseCase.
	* gm2-compiler/PCSymBuild.mod (InitDesExpr): Add else clause.
	(InitFunction): Add else clause.
	(InitConvert): Add else clause.
	(InitLeaf): Add else clause.
	(InitBinary): Add else clause.
	(InitUnary): Add else clause.
	* gm2-compiler/SymbolTable.def (GetNth): Re-write comment.
	(ForeachFieldEnumerationDo): Re-write comment stating alphabetical
	traversal.
	* gm2-compiler/SymbolTable.mod (GetNth): Re-write comment.
	Add case label for EnumerationSym and call GetItemFromList.
	(ForeachFieldEnumerationDo): Re-write comment stating alphabetical
	traversal.
	(SymEnumeration): Add ListOfFields used for declaration order.
	(MakeEnumeration): Initialize ListOfFields.
	(PutFieldEnumeration): Include Field in ListOfFields.
	* gm2-gcc/m2options.h (M2Options_SetCaseEnumChecking): New
	function.
	* gm2-lang.cc (gm2_langhook_handle_option): Add
	OPT_Wcase_enum case and call M2Options_SetCaseEnumChecking.
	* lang.opt (Wcase-enum): Add.

gcc/testsuite/ChangeLog:

	* gm2/switches/case/fail/missingclause.mod: New test.
	* gm2/switches/case/fail/switches-case-fail.exp: New test.
	* gm2/switches/case/pass/enumcase.mod: New test.
	* gm2/switches/case/pass/enumcase2.mod: New test.
	* gm2/switches/case/pass/switches-case-pass.exp: New test.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

5 files changed, 143 insertions, 0 deletions

diff --git a/gcc/testsuite/gm2/switches/case/fail/missingclause.mod b/gcc/testsuite/gm2/switches/case/fail/missingclause.mod
new file mode 100644
index 0000000..153ed9b
--- /dev/null
+++ b/gcc/testsuite/gm2/switches/case/fail/missingclause.mod
@@ -0,0 +1,23 @@
+MODULE missingclause ;  (*!m2iso+gm2*)
+
+
+TYPE
+   colour = (red, green, blue) ;
+
+
+PROCEDURE init (c: colour) ;
+BEGIN
+   CASE c OF
+
+   red,
+   blue: (* User forgets green.  *)
+
+   END
+END init ;
+
+
+VAR
+   rgb: colour ;
+BEGIN
+   init (rgb)
+END missingclause.
diff --git a/gcc/testsuite/gm2/switches/case/fail/switches-case-fail.exp b/gcc/testsuite/gm2/switches/case/fail/switches-case-fail.exp
new file mode 100644
index 0000000..2a3d48c
--- /dev/null
+++ b/gcc/testsuite/gm2/switches/case/fail/switches-case-fail.exp
@@ -0,0 +1,37 @@
+# Expect driver script for GCC Regression Tests
+# Copyright (C) 2023 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# This file was written by Gaius Mulley (gaius.mulley@southwales.ac.uk)
+# for GNU Modula-2.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+# load support procs
+load_lib gm2-torture.exp
+
+gm2_init_iso "${srcdir}/gm2/switches/case/fail/" -Wcase-enum -Werror
+
+foreach testcase [lsort [glob -nocomplain $srcdir/$subdir/*.mod]] {
+    # If we're only testing specific files and this isn't one of them, skip it.
+    if ![runtest_file_p $runtests $testcase] then {
+	continue
+    }
+
+    gm2-torture-fail $testcase
+}
diff --git a/gcc/testsuite/gm2/switches/case/pass/enumcase.mod b/gcc/testsuite/gm2/switches/case/pass/enumcase.mod
new file mode 100644
index 0000000..7876598f
--- /dev/null
+++ b/gcc/testsuite/gm2/switches/case/pass/enumcase.mod
@@ -0,0 +1,24 @@
+MODULE enumcase ;  (*!m2iso+gm2*)
+
+
+TYPE
+   colour = (red, blue, green) ;
+
+PROCEDURE init (c: colour) ;
+BEGIN
+   CASE c OF
+
+   red:  |
+   (* blue..green: *)
+   blue,
+   green:
+
+   END
+END init ;
+
+
+VAR
+   rgb: colour ;
+BEGIN
+   init (rgb)
+END enumcase.
diff --git a/gcc/testsuite/gm2/switches/case/pass/enumcase2.mod b/gcc/testsuite/gm2/switches/case/pass/enumcase2.mod
new file mode 100644
index 0000000..796bc80
--- /dev/null
+++ b/gcc/testsuite/gm2/switches/case/pass/enumcase2.mod
@@ -0,0 +1,22 @@
+MODULE enumcase2 ;  (*!m2iso+gm2*)
+
+
+TYPE
+   colour = (red, blue, green) ;
+
+PROCEDURE init (c: colour) ;
+BEGIN
+   CASE c OF
+
+   red:  |
+   blue..green:
+
+   END
+END init ;
+
+
+VAR
+   rgb: colour ;
+BEGIN
+   init (rgb)
+END enumcase2.
diff --git a/gcc/testsuite/gm2/switches/case/pass/switches-case-pass.exp b/gcc/testsuite/gm2/switches/case/pass/switches-case-pass.exp
new file mode 100644
index 0000000..92124ae
--- /dev/null
+++ b/gcc/testsuite/gm2/switches/case/pass/switches-case-pass.exp
@@ -0,0 +1,37 @@
+# Expect driver script for GCC Regression Tests
+# Copyright (C) 2003-2023 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# This file was written by Gaius Mulley (gaius.mulley@southwales.ac.uk)
+# for GNU Modula-2.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+# load support procs
+load_lib gm2-torture.exp
+
+gm2_init_iso "${srcdir}/gm2/switches/case/pass" -Wcase-enum -Werror
+
+foreach testcase [lsort [glob -nocomplain $srcdir/$subdir/*.mod]] {
+    # If we're only testing specific files and this isn't one of them, skip it.
+    if ![runtest_file_p $runtests $testcase] then {
+	continue
+    }
+
+    gm2-torture $testcase
+}