pythongh-120155: Add assertion to sre.c match_getindex() (python#120402)

vstinner · estyxx · commit 0fffa6cf7e40 · 2024-07-17T09:51:36.000+01:00
Add an assertion to help static analyzers to detect that i*2 cannot
overflow.
diff --git a/Modules/_sre/sre.c b/Modules/_sre/sre.c
@@ -2217,6 +2217,8 @@ 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
`@@ -2217,6 +2217,8 @@ match_getindex(MatchObject* self, PyObject* index)`
`2217`	`2217`	`return -1;`
`2218`	`2218`	`}`
`2219`	`2219`
	`2220`	`+ // Check that i*2 cannot overflow to make static analyzers happy`
	`2221`	`+ assert(i <= SRE_MAXGROUPS);`
`2220`	`2222`	`return i;`
`2221`	`2223`	`}`
`2222`	`2224`