[llvm] 829b29b - [MemoryLocation] strcat/strncat/strcpy read/write after their args.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 3 00:48:41 PST 2021
Author: Florian Hahn
Date: 2021-12-03T08:48:23Z
New Revision: 829b29b619f3dbbf767833867d027bba23dabb26
URL: https://github.com/llvm/llvm-project/commit/829b29b619f3dbbf767833867d027bba23dabb26
DIFF: https://github.com/llvm/llvm-project/commit/829b29b619f3dbbf767833867d027bba23dabb26.diff
LOG: [MemoryLocation] strcat/strncat/strcpy read/write after their args.
strcpy/strcat/strncat access memory starting from the passed in
pointers. Construct memory locations for their args using getAfter.
Discussed in D114872.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D114969
Added:
Modified:
llvm/lib/Analysis/MemoryLocation.cpp
llvm/test/Analysis/BasicAA/libfuncs.ll
llvm/test/Transforms/DeadStoreElimination/libcalls.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/MemoryLocation.cpp b/llvm/lib/Analysis/MemoryLocation.cpp
index 854ba83bd34a5..baf70565e9c41 100644
--- a/llvm/lib/Analysis/MemoryLocation.cpp
+++ b/llvm/lib/Analysis/MemoryLocation.cpp
@@ -213,6 +213,12 @@ MemoryLocation MemoryLocation::getForArgument(const CallBase *Call,
LibFunc F;
if (TLI && TLI->getLibFunc(*Call, F) && TLI->has(F)) {
switch (F) {
+ case LibFunc_strcpy:
+ case LibFunc_strcat:
+ case LibFunc_strncat:
+ assert((ArgIdx == 0 || ArgIdx == 1) && "Invalid argument index for str function");
+ return MemoryLocation::getAfter(Arg, AATags);
+
case LibFunc_memset_chk: {
assert(ArgIdx == 0 && "Invalid argument index for memset_chk");
LocationSize Size = LocationSize::afterPointer();
diff --git a/llvm/test/Analysis/BasicAA/libfuncs.ll b/llvm/test/Analysis/BasicAA/libfuncs.ll
index c9c457c7a4cfa..fc8d5b50b8726 100644
--- a/llvm/test/Analysis/BasicAA/libfuncs.ll
+++ b/llvm/test/Analysis/BasicAA/libfuncs.ll
@@ -132,8 +132,8 @@ declare i8* @strcat(i8*, i8*)
define i8* @test_strcat_read_write_after(i8* noalias %a, i8* noalias %b) {
; CHECK-LABEL: Function: test_strcat_read_write_after
-; CHECK: Both ModRef: Ptr: i8* %a <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
-; CHECK-NEXT: Just Ref: Ptr: i8* %b <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
+; CHECK: NoModRef: Ptr: i8* %a <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
+; CHECK-NEXT: NoModRef: Ptr: i8* %b <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
; CHECK-NEXT: Both ModRef: Ptr: i8* %a.gep.1 <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
; CHECK-NEXT: Just Ref: Ptr: i8* %b.gep.1 <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
; CHECK-NEXT: Both ModRef: Ptr: i8* %res <-> %res = tail call i8* @strcat(i8* %a.gep.1, i8* %b.gep.1)
@@ -157,8 +157,8 @@ declare i8* @strncat(i8*, i8*, i64)
define i8* @test_strncat_read_write_after(i8* noalias %a, i8* noalias %b, i64 %n) {
; CHECK-LABEL: Function: test_strncat_read_write_after
-; CHECK: Both ModRef: Ptr: i8* %a <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
-; CHECK-NEXT: Just Ref: Ptr: i8* %b <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
+; CHECK: NoModRef: Ptr: i8* %a <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
+; CHECK-NEXT: NoModRef: Ptr: i8* %b <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
; CHECK-NEXT: Both ModRef: Ptr: i8* %a.gep.1 <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
; CHECK-NEXT: Just Ref: Ptr: i8* %b.gep.1 <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
; CHECK-NEXT: Both ModRef: Ptr: i8* %res <-> %res = tail call i8* @strncat(i8* %a.gep.1, i8* %b.gep.1, i64 %n)
@@ -182,8 +182,8 @@ declare i8* @strcpy(i8*, i8*)
define i8* @test_strcpy_read_write_after(i8* noalias %a, i8* noalias %b) {
; CHECK-LABEL: Function: test_strcpy_read_write_after
-; CHECK: Just Mod: Ptr: i8* %a <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
-; CHECK-NEXT: Just Ref: Ptr: i8* %b <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
+; CHECK: NoModRef: Ptr: i8* %a <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
+; CHECK-NEXT: NoModRef: Ptr: i8* %b <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
; CHECK-NEXT: Just Mod: Ptr: i8* %a.gep.1 <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
; CHECK-NEXT: Just Ref: Ptr: i8* %b.gep.1 <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
; CHECK-NEXT: Just Mod: Ptr: i8* %res <-> %res = tail call i8* @strcpy(i8* %a.gep.1, i8* %b.gep.1)
diff --git a/llvm/test/Transforms/DeadStoreElimination/libcalls.ll b/llvm/test/Transforms/DeadStoreElimination/libcalls.ll
index 06ae9d04ad199..c0aa4c14fc1b4 100644
--- a/llvm/test/Transforms/DeadStoreElimination/libcalls.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/libcalls.ll
@@ -18,7 +18,6 @@ define void @test1(i8* %src) {
define void @strcpy_reads_after(i8* noalias %dest, i8* %src) {
; CHECK-LABEL: @strcpy_reads_after(
; CHECK-NEXT: [[SRC_2:%.*]] = getelementptr inbounds i8, i8* [[SRC:%.*]], i64 1
-; CHECK-NEXT: store i8 1, i8* [[SRC]], align 1
; CHECK-NEXT: store i8 99, i8* [[SRC_2]], align 1
; CHECK-NEXT: [[SRC_1:%.*]] = getelementptr inbounds i8, i8* [[SRC]], i64 1
; CHECK-NEXT: [[CALL:%.*]] = call i8* @strcpy(i8* [[DEST:%.*]], i8* [[SRC_1]])
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