https://gcc.gnu.org/g:fc276742e0db337c4d13e6c474abafd4796a6b69
commit r16-1608-gfc276742e0db337c4d13e6c474abafd4796a6b69
Author: Gaius Mulley <gaiusm...@gmail.com>
Date: Sun Jun 22 04:13:26 2025 +0100
[PR modula2/120731] error in Strings.Pos causing sigsegv
This patch corrects the m2log library procedure function
Strings.Pos which incorrectly sliced the wrong component
of the source string. The incorrect slice could cause
a sigsegv if negative slice indices were generated.
gcc/m2/ChangeLog:
PR modula2/120731
* gm2-libs-log/Strings.def (Delete): Rewrite comment.
* gm2-libs-log/Strings.mod (Pos): Rewrite.
(PosLower): New procedure function.
gcc/testsuite/ChangeLog:
PR modula2/120731
* gm2/pimlib/logitech/run/pass/teststrings.mod: New test.
Signed-off-by: Gaius Mulley <gaiusm...@gmail.com>
Diff:
---
gcc/m2/gm2-libs-log/Strings.def | 4 +-
gcc/m2/gm2-libs-log/Strings.mod | 77 ++++++++++++++--------
.../gm2/pimlib/logitech/run/pass/teststrings.mod | 16 +++++
3 files changed, 69 insertions(+), 28 deletions(-)
diff --git a/gcc/m2/gm2-libs-log/Strings.def b/gcc/m2/gm2-libs-log/Strings.def
index aea35f894889..2be4e4236d73 100644
--- a/gcc/m2/gm2-libs-log/Strings.def
+++ b/gcc/m2/gm2-libs-log/Strings.def
@@ -53,7 +53,9 @@ PROCEDURE Delete (VAR str: ARRAY OF CHAR; index: CARDINAL;
length: CARDINAL) ;
(*
- Pos - return the first position of, substr, in, str.
+ Pos - return the first position of substr in str.
+ If substr is not found in str then it returns
+ HIGH (str) + 1.
*)
PROCEDURE Pos (substr, str: ARRAY OF CHAR) : CARDINAL ;
diff --git a/gcc/m2/gm2-libs-log/Strings.mod b/gcc/m2/gm2-libs-log/Strings.mod
index 6046a102a52e..44f47b322505 100644
--- a/gcc/m2/gm2-libs-log/Strings.mod
+++ b/gcc/m2/gm2-libs-log/Strings.mod
@@ -83,39 +83,62 @@ END Delete ;
(*
- Pos - return the first position of, substr, in, str.
+ PosLower - return the first position of substr in str.
*)
-PROCEDURE Pos (substr, str: ARRAY OF CHAR) : CARDINAL ;
+PROCEDURE PosLower (substr, str: ARRAY OF CHAR) : CARDINAL ;
VAR
- i, k, l : INTEGER ;
- s1, s2, s3: DynamicStrings.String ;
+ i, strLen, substrLen : INTEGER ;
+ strS, substrS, scratchS: DynamicStrings.String ;
BEGIN
- s1 := DynamicStrings.InitString(str) ;
- s2 := DynamicStrings.InitString(substr) ;
- k := DynamicStrings.Length(s1) ;
- l := DynamicStrings.Length(s2) ;
+ strS := DynamicStrings.InitString (str) ;
+ substrS := DynamicStrings.InitString (substr) ;
+ strLen := DynamicStrings.Length (strS) ;
+ substrLen := DynamicStrings.Length (substrS) ;
i := 0 ;
REPEAT
- i := DynamicStrings.Index(s1, DynamicStrings.char(s2, 0), i) ;
- IF i>=0
+ i := DynamicStrings.Index (strS, DynamicStrings.char (substrS, 0), i) ;
+ IF i < 0
+ THEN
+ (* No match on first character therefore return now. *)
+ strS := DynamicStrings.KillString (strS) ;
+ substrS := DynamicStrings.KillString (substrS) ;
+ scratchS := DynamicStrings.KillString (scratchS) ;
+ RETURN( HIGH (str) + 1 )
+ ELSIF i + substrLen <= strLen
THEN
- s3 := DynamicStrings.Slice(s1, i, l) ;
- IF DynamicStrings.Equal(s3, s2)
+ scratchS := DynamicStrings.Slice (strS, i, i + substrLen) ;
+ IF DynamicStrings.Equal (scratchS, substrS)
THEN
- s1 := DynamicStrings.KillString(s1) ;
- s2 := DynamicStrings.KillString(s2) ;
- s3 := DynamicStrings.KillString(s3) ;
+ strS := DynamicStrings.KillString (strS) ;
+ substrS := DynamicStrings.KillString (substrS) ;
+ scratchS := DynamicStrings.KillString (scratchS) ;
RETURN( i )
END ;
- s3 := DynamicStrings.KillString(s3)
+ scratchS := DynamicStrings.KillString (scratchS)
END ;
- INC(i)
- UNTIL i>=k ;
- s1 := DynamicStrings.KillString(s1) ;
- s2 := DynamicStrings.KillString(s2) ;
- s3 := DynamicStrings.KillString(s3) ;
- RETURN( HIGH(str)+1 )
+ INC (i)
+ UNTIL i >= strLen ;
+ strS := DynamicStrings.KillString (strS) ;
+ substrS := DynamicStrings.KillString (substrS) ;
+ scratchS := DynamicStrings.KillString (scratchS) ;
+ RETURN( HIGH (str) + 1 )
+END PosLower ;
+
+
+(*
+ Pos - return the first position of substr in str.
+ If substr is not found in str then it returns
+ HIGH (str) + 1.
+*)
+
+PROCEDURE Pos (substr, str: ARRAY OF CHAR) : CARDINAL ;
+BEGIN
+ IF Length (substr) <= Length (str)
+ THEN
+ RETURN PosLower (substr, str)
+ END ;
+ RETURN( HIGH (str) + 1 )
END Pos ;
@@ -129,11 +152,11 @@ PROCEDURE Copy (str: ARRAY OF CHAR;
VAR
s1, s2: DynamicStrings.String ;
BEGIN
- s1 := DynamicStrings.InitString(str) ;
- s2 := DynamicStrings.Slice(s1, index, index+length) ;
- DynamicStrings.CopyOut(result, s2) ;
- s1 := DynamicStrings.KillString(s1) ;
- s2 := DynamicStrings.KillString(s2)
+ s1 := DynamicStrings.InitString (str) ;
+ s2 := DynamicStrings.Slice (s1, index, index+length) ;
+ DynamicStrings.CopyOut (result, s2) ;
+ s1 := DynamicStrings.KillString (s1) ;
+ s2 := DynamicStrings.KillString (s2)
END Copy ;
diff --git a/gcc/testsuite/gm2/pimlib/logitech/run/pass/teststrings.mod
b/gcc/testsuite/gm2/pimlib/logitech/run/pass/teststrings.mod
new file mode 100644
index 000000000000..1085d9cf4ecc
--- /dev/null
+++ b/gcc/testsuite/gm2/pimlib/logitech/run/pass/teststrings.mod
@@ -0,0 +1,16 @@
+MODULE teststrings ;
+
+IMPORT InOut,Strings;
+
+VAR
+ content : ARRAY[1..256] OF CHAR;
+ position: CARDINAL;
+
+(* the content is just random text. *)
+
+BEGIN
+ content := "erreur: In program module « essai3 »: attempting to pass (1)
parameters to procedure";
+ InOut.WriteString(content);
+ InOut.WriteLn;
+ position := Strings.Pos ("IMPORT", content);
+END teststrings .
