Include file:line information in CHECK_THROW to aid troubleshooting

Summary: see title Reviewed By: yfeldblum Differential Revision: D69070237 fbshipit-source-id: 28f5dfea8934e98dbb0f6f31314eaf85d561a913
facebook · Feb 5, 2025 · d653344 · d653344
1 parent 9d0b066
commit d653344
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Showing 3 changed files with 32 additions and 5 deletions.
diff --git a/folly/Exception.h b/folly/Exception.h
@@ -140,11 +140,13 @@ void checkFopenErrorExplicit(FILE* fp, int savedErrno, Args&&... args) {
  * If cond is not true, raise an exception of type E.  E must have a ctor that
  * works with const char* (a description of the failure).
  */
-#define CHECK_THROW(cond, E)                             \
-  do {                                                   \
-    if (!(cond)) {                                       \
-      folly::throw_exception<E>("Check failed: " #cond); \
-    }                                                    \
+#define CHECK_THROW(cond, E)                       \
+  do {                                             \
+    if (!(cond)) {                                 \
+      folly::throw_exception<E>(                   \
+          "Check failed: " #cond ", in " __FILE__  \
+          ":" FOLLY_PP_STRINGIZE_MACRO(__LINE__)); \
+    }                                              \
   } while (0)
 
 } // namespace folly
diff --git a/folly/Preprocessor.h b/folly/Preprocessor.h
@@ -112,6 +112,13 @@
  */
 #define FOLLY_PP_STRINGIZE(x) #x
 
+/**
+ * Use FOLLY_PP_STRINGIZE_MACRO(x) when you want the string representation
+ * of a non-string c++ preprocessing macro value, ex
+ * FOLLY_PP_STRINGIZE_MACRO(__LINE__).
+ */
+#define FOLLY_PP_STRINGIZE_MACRO(x) FOLLY_PP_STRINGIZE(x)
+
 #define FOLLY_PP_DETAIL_NARGS_1( \
     dummy,                       \
     _15,                         \

diff --git a/folly/test/ExceptionTest.cpp b/folly/test/ExceptionTest.cpp
@@ -121,5 +121,23 @@ TEST(ExceptionTest, makeSystemError) {
       << "what() string missing input message: " << ex.what();
 }
 
+TEST(ExceptionTest, testCheckThrow) {
+  auto throwIf = [](bool shouldThrow) {
+    CHECK_THROW(!shouldThrow, std::runtime_error);
+  };
+  EXPECT_NO_THROW(throwIf(false));
+  EXPECT_THROW(throwIf(true), std::runtime_error);
+
+  try {
+    throwIf(true);
+  } catch (const std::runtime_error& e) {
+    auto msg = std::string(e.what());
+    EXPECT_TRUE(msg.find("Check failed: !shouldThrow") != std::string::npos);
+    EXPECT_TRUE(msg.find("folly/test/ExceptionTest.cpp") != std::string::npos);
+    auto lineNumber = msg.substr(msg.rfind(':') + 1);
+    EXPECT_TRUE(std::all_of(lineNumber.begin(), lineNumber.end(), ::isdigit));
+  }
+}
+
 } // namespace test
 } // namespace folly