[clang][ubsan] Split Implicit Integer Truncation Sanitizer into unsigned and signed checks

Summary:
As per IRC disscussion, it seems we really want to have more fine-grained `-fsanitize=implicit-integer-truncation`:
* A check when both of the types are unsigned.
* Another check for the other cases (either one of the types is signed, or both of the types is signed).

This is clang part.
Compiler-rt part is D50902.

Reviewers: rsmith, vsk, Sanitizers

Reviewed by: rsmith

Differential Revision: https://reviews.llvm.org/D50901

llvm-svn: 344230

1 files changed, 33 insertions, 5 deletions

diff --git a/clang/test/CodeGen/catch-implicit-integer-truncations-basics-negatives.c b/clang/test/CodeGen/catch-implicit-integer-truncations-basics-negatives.c
index d5554b98d4a..1b543a3a7ff 100644
--- a/clang/test/CodeGen/catch-implicit-integer-truncations-basics-negatives.c
+++ b/clang/test/CodeGen/catch-implicit-integer-truncations-basics-negatives.c
@@ -1,7 +1,9 @@
-// RUN: %clang_cc1 -fsanitize=implicit-integer-truncation -fsanitize-recover=implicit-integer-truncation -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_implicit_conversion" --check-prefixes=CHECK
+// RUN: %clang_cc1 -fsanitize=implicit-unsigned-integer-truncation,implicit-signed-integer-truncation -fsanitize-recover=implicit-unsigned-integer-truncation,implicit-signed-integer-truncation -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_implicit_conversion" --check-prefixes=CHECK
 
-// CHECK-DAG: @[[LINE_100_TRUNCATION:.*]] = {{.*}}, i32 100, i32 10 }, {{.*}}, {{.*}}, i8 0 }
-// CHECK-DAG: @[[LINE_300_TRUNCATION:.*]] = {{.*}}, i32 300, i32 10 }, {{.*}}, {{.*}}, i8 0 }
+// CHECK-DAG: @[[LINE_100_UNSIGNED_TRUNCATION:.*]] = {{.*}}, i32 100, i32 10 }, {{.*}}, {{.*}}, i8 1 }
+// CHECK-DAG: @[[LINE_200_UNSIGNED_TRUNCATION:.*]] = {{.*}}, i32 200, i32 10 }, {{.*}}, {{.*}}, i8 1 }
+// CHECK-DAG: @[[LINE_300_SIGNED_TRUNCATION:.*]] = {{.*}}, i32 300, i32 10 }, {{.*}}, {{.*}}, i8 2 }
+// CHECK-DAG: @[[LINE_400_SIGNED_TRUNCATION:.*]] = {{.*}}, i32 400, i32 10 }, {{.*}}, {{.*}}, i8 2 }
 
 //----------------------------------------------------------------------------//
 // Unsigned case.
@@ -10,7 +12,7 @@
 // CHECK-LABEL: @blacklist_0_convert_unsigned_int_to_unsigned_char
 __attribute__((no_sanitize("undefined"))) unsigned char blacklist_0_convert_unsigned_int_to_unsigned_char(unsigned int x) {
   // We are not in "undefined" group, so that doesn't work.
-  // CHECK: call void @__ubsan_handle_implicit_conversion(i8* bitcast ({ {{{.*}}}, {{{.*}}}*, {{{.*}}}*, i8 }* @[[LINE_100_TRUNCATION]] to i8*)
+  // CHECK: call void @__ubsan_handle_implicit_conversion(i8* bitcast ({ {{{.*}}}, {{{.*}}}*, {{{.*}}}*, i8 }* @[[LINE_100_UNSIGNED_TRUNCATION]] to i8*)
 #line 100
   return x;
 }
@@ -30,6 +32,19 @@ __attribute__((no_sanitize("implicit-integer-truncation"))) unsigned char blackl
   return x;
 }
 
+// CHECK-LABEL: @blacklist_4_convert_unsigned_int_to_unsigned_char
+__attribute__((no_sanitize("implicit-unsigned-integer-truncation"))) unsigned char blacklist_4_convert_unsigned_int_to_unsigned_char(unsigned int x) {
+  return x;
+}
+
+// CHECK-LABEL: @blacklist_5_convert_unsigned_int_to_unsigned_char
+__attribute__((no_sanitize("implicit-signed-integer-truncation"))) unsigned char blacklist_5_convert_unsigned_int_to_unsigned_char(unsigned int x) {
+  // This is an unsigned truncation, not signed-one.
+  // CHECK: call void @__ubsan_handle_implicit_conversion(i8* bitcast ({ {{{.*}}}, {{{.*}}}*, {{{.*}}}*, i8 }* @[[LINE_200_UNSIGNED_TRUNCATION]] to i8*)
+#line 200
+  return x;
+}
+
 //----------------------------------------------------------------------------//
 // Signed case.
 //----------------------------------------------------------------------------//
@@ -37,7 +52,7 @@ __attribute__((no_sanitize("implicit-integer-truncation"))) unsigned char blackl
 // CHECK-LABEL: @blacklist_0_convert_signed_int_to_signed_char
 __attribute__((no_sanitize("undefined"))) signed char blacklist_0_convert_signed_int_to_signed_char(signed int x) {
   // We are not in "undefined" group, so that doesn't work.
-  // CHECK: call void @__ubsan_handle_implicit_conversion(i8* bitcast ({ {{{.*}}}, {{{.*}}}*, {{{.*}}}*, i8 }* @[[LINE_300_TRUNCATION]] to i8*)
+  // CHECK: call void @__ubsan_handle_implicit_conversion(i8* bitcast ({ {{{.*}}}, {{{.*}}}*, {{{.*}}}*, i8 }* @[[LINE_300_SIGNED_TRUNCATION]] to i8*)
 #line 300
   return x;
 }
@@ -56,3 +71,16 @@ __attribute__((no_sanitize("implicit-conversion"))) signed char blacklist_2_conv
 __attribute__((no_sanitize("implicit-integer-truncation"))) signed char blacklist_3_convert_signed_int_to_signed_char(signed int x) {
   return x;
 }
+
+// CHECK-LABEL: @blacklist_4_convert_signed_int_to_signed_char
+__attribute__((no_sanitize("implicit-signed-integer-truncation"))) signed char blacklist_4_convert_signed_int_to_signed_char(signed int x) {
+  return x;
+}
+
+// CHECK-LABEL: @blacklist_5_convert_signed_int_to_signed_char
+__attribute__((no_sanitize("implicit-unsigned-integer-truncation"))) signed char blacklist_5_convert_signed_int_to_signed_char(signed int x) {
+  // This is an signed truncation, not unsigned-one.
+  // CHECK: call void @__ubsan_handle_implicit_conversion(i8* bitcast ({ {{{.*}}}, {{{.*}}}*, {{{.*}}}*, i8 }* @[[LINE_400_SIGNED_TRUNCATION]] to i8*)
+#line 400
+  return x;
+}