[NFC] Including <string> in llvm-cxxdump/Error.cpp

[qiongsiwu1]

Summary

A recent commit removed <string> from ErrorHandling.h. The removal caused <string> to be no longer included for llvm/tools/llvm-cxxdump/Error.cpp which uses the string type.

This patch adds <string> to llvm/tools/llvm-cxxdump/Error.cpp.

[jsji]

LGTM.

[RKSimon]

@qiongsiwu1 I ran check-llvm on windows, wsl and linux boxes and didn't hit this - does this mean llvm-cxxdump isn't built/tested by default at all?

[qiongsiwu1]

In D111354#3050388, @RKSimon wrote:

@qiongsiwu1 I ran check-llvm on windows, wsl and linux boxes and didn't hit this - does this mean llvm-cxxdump isn't built/tested by default at all?

Thanks for looking into this! llvm-cxxdump builds on Linux without explicitly including the header, at least during our testing. For Linux on Power, it happens to work for us due to the build compiler including the header through other means as a side effect (Specifically, the utility header including cstdlib). The build failed on AIX because the libc++ on the platform not having such side effects.

[RKSimon]

In D111354#3050830, @qiongsiwu1 wrote:

In D111354#3050388, @RKSimon wrote:

@qiongsiwu1 I ran check-llvm on windows, wsl and linux boxes and didn't hit this - does this mean llvm-cxxdump isn't built/tested by default at all?

Thanks for looking into this! llvm-cxxdump builds on Linux without explicitly including the header, at least during our testing. For Linux on Power, it happens to work for us due to the build compiler including the header through other means as a side effect (Specifically, the utility header including cstdlib). The build failed on AIX because the libc++ on the platform not having such side effects.

Thanks for the clarification - the lack of buildbot failures suggested I'd gotten it mostly right - implicit dependencies will always hit in unexpected places of course.....

[qiongsiwu1]

In D111354#3050854, @RKSimon wrote:

In D111354#3050830, @qiongsiwu1 wrote:

In D111354#3050388, @RKSimon wrote:

@qiongsiwu1 I ran check-llvm on windows, wsl and linux boxes and didn't hit this - does this mean llvm-cxxdump isn't built/tested by default at all?

Thanks for looking into this! llvm-cxxdump builds on Linux without explicitly including the header, at least during our testing. For Linux on Power, it happens to work for us due to the build compiler including the header through other means as a side effect (Specifically, the utility header including cstdlib). The build failed on AIX because the libc++ on the platform not having such side effects.

Thanks for the clarification - the lack of buildbot failures suggested I'd gotten it mostly right - implicit dependencies will always hit in unexpected places of course.....

Not a problem! This was rather unexpected to us as well.

llvm/tools/llvm-cxxdump/Error.cpp

 //===- Error.cpp - system_error extensions for llvm-cxxdump -----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This defines a new error_category for the llvm-cxxdump tool.
 //
 //===----------------------------------------------------------------------===//
 
 #include "Error.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <string>
 
 using namespace llvm;
 
 namespace {
 // FIXME: This class is only here to support the transition to llvm::Error. It
 // will be removed once this transition is complete. Clients should prefer to
 // deal with the Error value directly, rather than converting to error_code.
 class cxxdump_error_category : public std::error_category {