[3.12] gh-120155: Add assertion to sre.c match_getindex() (GH-120402) (#120410)

miss-islington · vstinner · web-flow · commit ab309343655a · 2024-06-12T13:57:45.000Z
gh-120155: Add assertion to sre.c match_getindex() (GH-120402) Add an assertion to help static analyzers to detect that i*2 cannot overflow. (cherry picked from commit 42b25dd) Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Modules/_sre/sre.c b/Modules/_sre/sre.c
@@ -2167,6 +2167,8 @@ match_getindex(MatchObject* self, PyObject* index)
         return -1;
     }
 
+    // Check that i*2 cannot overflow to make static analyzers happy
+    assert(i <= SRE_MAXGROUPS);
     return i;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -2167,6 +2167,8 @@ match_getindex(MatchObject* self, PyObject* index)`
`2167`	`2167`	`return -1;`
`2168`	`2168`	`}`
`2169`	`2169`
	`2170`	`+ // Check that i*2 cannot overflow to make static analyzers happy`
	`2171`	`+ assert(i <= SRE_MAXGROUPS);`
`2170`	`2172`	`return i;`
`2171`	`2173`	`}`
`2172`	`2174`