[UBSan] Add report deduplication for -fsanitize=function.

[samsonov]

Summary

Make sure we don't print the error report from -fsanitize=function
twice for the same source location, as we do in another UBSan handlers.

[pcc]

test/ubsan/TestCases/TypeCheck/Function/function.cpp

28–34

Can we move this call to the top of main and re-instate its CHECK-NOT? That way, we know that if we don't warn about it, it was not because of deduplication.

30

Do we want a NOSYM-NOT here as well?

[samsonov]

• Fix test case according to review.

test/ubsan/TestCases/TypeCheck/Function/function.cpp

28–34

Done

30

Done

[pcc]

LGTM

lib/ubsan/ubsan_handlers.cc

void __ubsan::__ubsan_handle_load_invalid_value_abort(InvalidValueData *Data,
   GET_REPORT_OPTIONS(true);
   handleLoadInvalidValue(Data, Val, Opts);
   Die();
 }
 
 static void handleFunctionTypeMismatch(FunctionTypeMismatchData *Data,
                                        ValueHandle Function,
                                        ReportOptions Opts) {
-  const char *FName = "(unknown)";
+  SourceLocation CallLoc = Data->Loc.acquire();
+  if (ignoreReport(CallLoc, Opts))
+    return;
 
-  Location Loc = getFunctionLocation(Function, &FName);
+  ScopedReport R(Opts, CallLoc);
 
-  ScopedReport R(Opts, Loc);
+  const char *FName = "(unknown)";
+  Location FLoc = getFunctionLocation(Function, &FName);
 
-  Diag(Data->Loc, DL_Error,
+  Diag(CallLoc, DL_Error,
        "call to function %0 through pointer to incorrect function type %1")
       << FName << Data->Type;
-  Diag(Loc, DL_Note, "%0 defined here") << FName;
+  Diag(FLoc, DL_Note, "%0 defined here") << FName;
 }
 
 void
 __ubsan::__ubsan_handle_function_type_mismatch(FunctionTypeMismatchData *Data,
                                                ValueHandle Function) {
   GET_REPORT_OPTIONS(false);
   handleFunctionTypeMismatch(Data, Function, Opts);
 }

test/ubsan/TestCases/TypeCheck/Function/function.cpp

 // RUN: %clangxx -fsanitize=function %s -O3 -g -o %t
 // RUN: %run %t 2>&1 | FileCheck %s
 // Verify that we can disable symbolization if needed:
 // RUN: UBSAN_OPTIONS=symbolize=0 ASAN_OPTIONS=symbolize=0 %run %t 2>&1 | FileCheck %s --check-prefix=NOSYM
 
 // -fsanitize=function is unsupported on Darwin yet.
 // XFAIL: darwin
 
 #include <stdint.h>
 
 void f() {}
 
 void g(int x) {}
 
-int main(void) {
-  // CHECK: runtime error: call to function f() through pointer to incorrect function type 'void (*)(int)'
+void make_valid_call() {
+  // CHECK-NOT: runtime error: call to function g
+  reinterpret_cast<void (*)(int)>(reinterpret_cast<uintptr_t>(g))(42);
+}
+
+void make_invalid_call() {
+  // CHECK: function.cpp:25:3: runtime error: call to function f() through pointer to incorrect function type 'void (*)(int)'
   // CHECK-NEXT: function.cpp:11: note: f() defined here
-  // NOSYM: runtime error: call to function (unknown) through pointer to incorrect function type 'void (*)(int)'
+  // NOSYM: function.cpp:25:3: runtime error: call to function (unknown) through pointer to incorrect function type 'void (*)(int)'
   // NOSYM-NEXT: ({{.*}}+0x{{.*}}): note: (unknown) defined here
   reinterpret_cast<void (*)(int)>(reinterpret_cast<uintptr_t>(f))(42);
+}
 
-  // CHECK-NOT: runtime error: call to function g
-  reinterpret_cast<void (*)(int)>(reinterpret_cast<uintptr_t>(g))(42);
+int main(void) {
+  make_valid_call();
+  make_invalid_call();
+  // Check that no more errors will be printed.
+  // CHECK-NOT: runtime error: call to function
+  // NOSYM-NOT: runtime error: call to function
+  make_invalid_call();
 }