https://gcc.gnu.org/g:aeee63ffbf4f4fbc4d90d8aae808d6b67f0148a3
commit r14-9710-gaeee63ffbf4f4fbc4d90d8aae808d6b67f0148a3
Author: Gaius Mulley <gaiusm...@gmail.com>
Date: Thu Mar 28 16:49:44 2024 +0000
PR modula2/114520 Incorrect ordering of import/export statements cause
confusion
The error recovery causes misleading error messages to appear if an
EXPORT and IMPORT statement are in the wrong order. This patch
detects the incorrect order and issues an error message and prevents
error recovery. The fix should be improved and made more general if
another similar case is required.
gcc/m2/ChangeLog:
PR modula2/114520
* gm2-compiler/P0SyntaxCheck.bnf (DetectImport): New
procedure.
(EnableImportCheck): New boolean.
(Expect): Call DetectImport.
(Export): Set EnableImportCheck TRUE before ';' and FALSE
afterwards.
Signed-off-by: Gaius Mulley <gaiusm...@gmail.com>
Diff:
---
gcc/m2/gm2-compiler/P0SyntaxCheck.bnf | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/gcc/m2/gm2-compiler/P0SyntaxCheck.bnf
b/gcc/m2/gm2-compiler/P0SyntaxCheck.bnf
index c1c86c1827d..07f861adac9 100644
--- a/gcc/m2/gm2-compiler/P0SyntaxCheck.bnf
+++ b/gcc/m2/gm2-compiler/P0SyntaxCheck.bnf
@@ -82,9 +82,10 @@ CONST
(* giving up.
*)
VAR
- seenError : BOOLEAN ;
- LastIdent : Name ;
- InsertCount: CARDINAL ;
+ EnableImportCheck,
+ seenError : BOOLEAN ;
+ LastIdent : Name ;
+ InsertCount : CARDINAL ;
PROCEDURE ErrorString (s: String) ;
@@ -319,6 +320,21 @@ BEGIN
END PeepToken ;
+(*
+ DetectImport - checks whether the next token is an import or from and if so
+ generates an error message. This is called after an export
+ statement to notify the user that the ordering is incorrect.
+*)
+
+PROCEDURE DetectImport ;
+BEGIN
+ IF (currenttoken = importtok) OR (currenttoken = fromtok)
+ THEN
+ ErrorArray ('an {%AkIMPORT} statement must preceed an {%kEXPORT}
statement')
+ END
+END DetectImport ;
+
+
(*
Expect -
*)
@@ -328,6 +344,10 @@ BEGIN
IF currenttoken=t
THEN
GetToken ;
+ IF EnableImportCheck
+ THEN
+ DetectImport
+ END ;
IF Pass0
THEN
PeepToken (stopset0, stopset1, stopset2)
@@ -347,6 +367,7 @@ END Expect ;
PROCEDURE CompilationUnit () : BOOLEAN ;
BEGIN
seenError := FALSE ;
+ EnableImportCheck := FALSE ;
InsertCount := 0 ;
FileUnit (SetOfStop0{eoftok}, SetOfStop1{}, SetOfStop2{}) ;
RETURN NOT seenError
@@ -883,7 +904,9 @@ Priority := "[" ConstExpression "]" =:
Export := "EXPORT" ( "QUALIFIED" IdentList |
"UNQUALIFIED" IdentList |
IdentList
- ) ";" =:
+ ) %
EnableImportCheck := TRUE %
+ ";" %
EnableImportCheck := FALSE %
+ =:
Import := "FROM" Ident "IMPORT" IdentList ";" |
"IMPORT" %
PushTtok (ImportTok, GetTokenNo () -1)
