[clang] aa972f6 - -fsanitize=function, MicrosoftMangle: Switch to xxh3_64bits

[Fangrui Song via cfe-commits]

Author: Fangrui Song
Date: 2023-07-19T15:20:50-07:00
New Revision: aa972f607c55cdbab3b9182aacb3ed6a5d9e73e1

URL: https://github.com/llvm/llvm-project/commit/aa972f607c55cdbab3b9182aacb3ed6a5d9e73e1
DIFF: https://github.com/llvm/llvm-project/commit/aa972f607c55cdbab3b9182aacb3ed6a5d9e73e1.diff

LOG: -fsanitize=function,MicrosoftMangle: Switch to xxh3_64bits

Following recent changes switching from xxh64 to xxh32 for better
hashing performance (e.g., D154813). These particular instances likely
have negligible time, but this change moves us toward removing xxHash64.

The type hash for -fsanitize=function will change, following a recent
change D148785 (not in any release yet) to the type hash scheme, though
sanitizers don't sign up for cross-version compatibility anyway.

The MicrosoftMangle instance is for internal symbols that need no
compatibility guarantee, as emphasized by the comment.

Added: 
    

Modified: 
    clang/lib/AST/MicrosoftMangle.cpp
    clang/lib/CodeGen/CodeGenFunction.cpp
    clang/test/CodeGen/ubsan-function.cpp
    clang/test/CodeGenCXX/catch-undef-behavior.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 430a57d7b4ec01..3306d90dc85664 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -485,7 +485,7 @@ MicrosoftMangleContextImpl::MicrosoftMangleContextImpl(ASTContext &Context,
   SourceManager &SM = Context.getSourceManager();
   if (const FileEntry *FE = SM.getFileEntryForID(SM.getMainFileID())) {
     // Truncate the hash so we get 8 characters of hexadecimal.
-    uint32_t TruncatedHash = uint32_t(xxHash64(FE->getName()));
+    uint32_t TruncatedHash = uint32_t(xxh3_64bits(FE->getName()));
     AnonymousNamespaceHash = llvm::utohexstr(TruncatedHash);
   } else {
     // If we don't have a path to the main file, we'll just use 0.

diff  --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index b8d39371a93308..fab70b66d1d965 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -577,8 +577,8 @@ CodeGenFunction::getUBSanFunctionTypeHash(QualType Ty) const {
   std::string Mangled;
   llvm::raw_string_ostream Out(Mangled);
   CGM.getCXXABI().getMangleContext().mangleTypeName(Ty, Out, false);
-  return llvm::ConstantInt::get(CGM.Int32Ty,
-                                static_cast<uint32_t>(llvm::xxHash64(Mangled)));
+  return llvm::ConstantInt::get(
+      CGM.Int32Ty, static_cast<uint32_t>(llvm::xxh3_64bits(Mangled)));
 }
 
 void CodeGenFunction::EmitKernelMetadata(const FunctionDecl *FD,

diff  --git a/clang/test/CodeGen/ubsan-function.cpp b/clang/test/CodeGen/ubsan-function.cpp
index ba55ee021cc9df..1c281c8544578f 100644
--- a/clang/test/CodeGen/ubsan-function.cpp
+++ b/clang/test/CodeGen/ubsan-function.cpp
@@ -17,7 +17,7 @@ void fun() {}
 // CHECK: [[LABEL1]]:
 // CHECK: getelementptr <{ i32, i32 }>, ptr {{.*}}, i32 -1, i32 1, !nosanitize
 // CHECK: load i32, ptr {{.*}}, align {{.*}}, !nosanitize
-// CHECK: icmp eq i32 {{.*}}, -1522505972, !nosanitize
+// CHECK: icmp eq i32 {{.*}}, 905068220, !nosanitize
 // CHECK: br i1 {{.*}}, label %[[LABEL3:.*]], label %[[LABEL2:[^,]*]], {{.*}}!nosanitize
 // CHECK: [[LABEL2]]:
 // 64:    call void @__ubsan_handle_function_type_mismatch_abort(ptr @[[#]], i64 %[[#]]) #[[#]], !nosanitize
@@ -32,4 +32,4 @@ void fun() {}
 // CHECK-NEXT:   ret void
 void caller(void (*f)()) { f(); }
 
-// CHECK: ![[FUNCSAN]] = !{i32 -1056584962, i32 -1522505972}
+// CHECK: ![[FUNCSAN]] = !{i32 -1056584962, i32 905068220}

diff  --git a/clang/test/CodeGenCXX/catch-undef-behavior.cpp b/clang/test/CodeGenCXX/catch-undef-behavior.cpp
index 9e4f0fb402c28a..6fd7d16f86369f 100644
--- a/clang/test/CodeGenCXX/catch-undef-behavior.cpp
+++ b/clang/test/CodeGenCXX/catch-undef-behavior.cpp
@@ -405,7 +405,7 @@ void indirect_function_call(void (*p)(int)) {
   // CalleeTypeHash check
   // CHECK: [[CalleeTypeHashPtr:%.+]] = getelementptr <{ i32, i32 }>, ptr [[PTR]], i32 -1, i32 1
   // CHECK-NEXT: [[CalleeTypeHash:%.+]] = load i32, ptr [[CalleeTypeHashPtr]]
-  // CHECK-NEXT: [[CalleeTypeHashMatch:%.+]] = icmp eq i32 [[CalleeTypeHash]], 27004076
+  // CHECK-NEXT: [[CalleeTypeHashMatch:%.+]] = icmp eq i32 [[CalleeTypeHash]], -1988405058
   // CHECK-NEXT: br i1 [[CalleeTypeHashMatch]]
 
   p(42);
@@ -740,4 +740,4 @@ void ThisAlign::this_align_lambda_2() {
 
 // CHECK: attributes [[NR_NUW]] = { noreturn nounwind }
 
-// CHECK-FUNCSAN: ![[FUNCSAN]] = !{i32 -1056584962, i32 -1302768377}
+// CHECK-FUNCSAN: ![[FUNCSAN]] = !{i32 -1056584962, i32 -1000226989}