[DFSan] Directly create gep inbounds for arg origin tls (NFCI)

nikic · nikic · commit 7af5b68a03bb · 2024-05-29T16:01:37.000+02:00
Calling code explicitly checks that ArgNo is inbounds. NFCI
because constant expression creation already infers it, this just
makes it explicit.
diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -1804,8 +1804,8 @@ Value *DFSanFunction::getRetvalTLS(Type *T, IRBuilder<> &IRB) {
 Value *DFSanFunction::getRetvalOriginTLS() { return DFS.RetvalOriginTLS; }
 
 Value *DFSanFunction::getArgOriginTLS(unsigned ArgNo, IRBuilder<> &IRB) {
-  return IRB.CreateConstGEP2_64(DFS.ArgOriginTLSTy, DFS.ArgOriginTLS, 0, ArgNo,
-                                "_dfsarg_o");
+  return IRB.CreateConstInBoundsGEP2_64(DFS.ArgOriginTLSTy, DFS.ArgOriginTLS, 0,
+                                        ArgNo, "_dfsarg_o");
 }
 
 Value *DFSanFunction::getOrigin(Value *V) {

Original file line number	Diff line number	Diff line change
`@@ -1804,8 +1804,8 @@ Value DFSanFunction::getRetvalTLS(Type T, IRBuilder<> &IRB) {`
`1804`	`1804`	`Value *DFSanFunction::getRetvalOriginTLS() { return DFS.RetvalOriginTLS; }`
`1805`	`1805`
`1806`	`1806`	`Value *DFSanFunction::getArgOriginTLS(unsigned ArgNo, IRBuilder<> &IRB) {`
`1807`		`- return IRB.CreateConstGEP2_64(DFS.ArgOriginTLSTy, DFS.ArgOriginTLS, 0, ArgNo,`
`1808`		`- "_dfsarg_o");`
	`1807`	`+ return IRB.CreateConstInBoundsGEP2_64(DFS.ArgOriginTLSTy, DFS.ArgOriginTLS, 0,`
	`1808`	`+ ArgNo, "_dfsarg_o");`
`1809`	`1809`	`}`
`1810`	`1810`
`1811`	`1811`	`Value DFSanFunction::getOrigin(Value V) {`