[llvm] 79c5479 - Support: Pass wrapped Error's error code through FileError

[Duncan P. N. Exon Smith via llvm-commits]

Author: Duncan P. N. Exon Smith
Date: 2021-11-12T21:19:09-08:00
New Revision: 79c5479822e6039f764968225181b93f4c2924ad

URL: https://github.com/llvm/llvm-project/commit/79c5479822e6039f764968225181b93f4c2924ad
DIFF: https://github.com/llvm/llvm-project/commit/79c5479822e6039f764968225181b93f4c2924ad.diff

LOG: Support: Pass wrapped Error's error code through FileError

Change FileError to pass through the error code from the Error it wraps.
This allows APIs that return ECError to transition to FileError without
changing returned std::error_code.

This was extracted from https://reviews.llvm.org/D109345.

Differential Revision: https://reviews.llvm.org/D113225

Added: 
    

Modified: 
    llvm/lib/Support/Error.cpp
    llvm/unittests/Support/ErrorTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Support/Error.cpp b/llvm/lib/Support/Error.cpp
index 446a9d2b6e7e8..8bfc8ee7a8cc6 100644
--- a/llvm/lib/Support/Error.cpp
+++ b/llvm/lib/Support/Error.cpp
@@ -80,8 +80,11 @@ std::error_code inconvertibleErrorCode() {
 }
 
 std::error_code FileError::convertToErrorCode() const {
-  return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
-                         *ErrorErrorCat);
+  std::error_code NestedEC = Err->convertToErrorCode();
+  if (NestedEC == inconvertibleErrorCode())
+    return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
+                           *ErrorErrorCat);
+  return NestedEC;
 }
 
 Error errorCodeToError(std::error_code EC) {

diff  --git a/llvm/unittests/Support/ErrorTest.cpp b/llvm/unittests/Support/ErrorTest.cpp
index 4d557cc7cbb00..3ca94b2a2aef9 100644
--- a/llvm/unittests/Support/ErrorTest.cpp
+++ b/llvm/unittests/Support/ErrorTest.cpp
@@ -963,6 +963,33 @@ TEST(Error, FileErrorTest) {
   });
 }
 
+TEST(Error, FileErrorErrorCode) {
+  for (std::error_code EC : {
+           make_error_code(std::errc::not_supported),
+           make_error_code(std::errc::invalid_argument),
+           make_error_code(std::errc::no_such_file_or_directory),
+       }) {
+    EXPECT_EQ(EC, errorToErrorCode(
+                      createFileError("file.bin", EC)));
+    EXPECT_EQ(EC, errorToErrorCode(
+                      createFileError("file.bin", /*Line=*/5, EC)));
+    EXPECT_EQ(EC, errorToErrorCode(
+                      createFileError("file.bin", errorCodeToError(EC))));
+    EXPECT_EQ(EC, errorToErrorCode(
+                      createFileError("file.bin", /*Line=*/5, errorCodeToError(EC))));
+  }
+
+  // inconvertibleErrorCode() should be wrapped to avoid a fatal error.
+  EXPECT_EQ(
+      "A file error occurred.",
+      errorToErrorCode(createFileError("file.bin", inconvertibleErrorCode()))
+          .message());
+  EXPECT_EQ(
+      "A file error occurred.",
+      errorToErrorCode(createFileError("file.bin", /*Line=*/5, inconvertibleErrorCode()))
+          .message());
+}
+
 enum class test_error_code {
   unspecified = 1,
   error_1,