bazel_tools 13.14 compile error on macOS with --cxxopt="-std=c++14"

[mbland]

Description of the bug:

Building the following with rules_java 8.7.0 or 8.7.1, which use bazel_tools 13.14 (see bazelbuild/rules_java: Update rules_java to 8.7.0 and java_tools to 13.14), fails on macOS with:

$ bazel build --cxxopt="-std=c++14" @remote_java_tools//:filesystem

[ ...snip... ]
external/rules_java++toolchains+remote_java_tools/java_tools/src/main/cpp/util/file_posix.cc:137:7: error: no matching function for call to 'mkdtemp'
  137 |   if (mkdtemp(&path.data()[0]) == nullptr) {                                                                                                         
      |       ^~~~~~~                                                         
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.2.sdk/usr/include/unistd.h:665:7: note: candidate function not v
iable: 1st argument ('const value_type *' (aka 'const char *')) would lose const qualifier
  665 | char    *mkdtemp(char *);
      |          ^       ~~~~~~
1 error generated.
Error in child process '/usr/bin/xcrun'. 1

We hit this in our build while calling default_java_toolchain with dependencies on @remote_java_tools//:ijar_cc_binary and @remote_java_tools//:singlejar_cc_bin. Both of these apparently depend on @remote_java_tools//:filesystem.

I selected the "Core" category since I didn't see one for bazel_tools. Cross-reference: bazelbuild/java_tools#93 (comment)

cc: @saraadams

Which category does this issue belong to?

Core

What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Update rules_java to 8.7.0 (or 8.7.1) in any project, and import the remote_java_tools repo:

bazel_dep(name = "rules_java", version = "8.7.1")
    
java_toolchains = use_extension(
    "@rules_java//java:extensions.bzl", "toolchains"
)
use_repo(java_toolchains, "remote_java_tools")

Then build on macOS using the macOS SDKs for 14.5 or 15.2:

bazel build --cxxopt="-std=c++14" @remote_java_tools//:filesystem

Which operating system are you running Bazel on?

macOS 15.2 (24C101)

What is the output of bazel info release?

release 9.0.0-pre.20250106.2

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse HEAD ?

If this is a regression, please try to identify the Bazel commit where the bug was introduced with bazelisk --bisect.

This appears due to the following change: 6906ba6#diff-83cfe165f1bd78a7736edc353ec60148796236c9076c75ed152d35e25a70077bL136-L137 (doesn't jump; search for mkdtemp)

This changes lines 136-137 of src/main/cpp/util/file_posix.cc from:

std::string result(prefix + "XXXXXX");
if (mkdtemp(&result[0]) == nullptr) {

to:

std::string path(other_path.AsNativePath() + ".tmp.XXXXXX");
if (mkdtemp(&path.data()[0]) == nullptr) {

std::string.data() returns a const char *, whereas the previous &result[0] returns char *.

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

The full compile command:

ERROR: .../external/rules_java++toolchains+remote_java_tools/BUILD:256:11:
  Compiling java_tools/src/main/cpp/util/file_posix.cc [for tool] failed: (Exit 1):
  wrapped_clang_pp failed:
  error executing CppCompile command
 (from target @@rules_java++toolchains+remote_java_tools//:filesystem)
  (cd .../sandbox/darwin-sandbox/1292/execroot/_main && \                                        
  exec env - \                                                                                                                                               
    APPLE_SDK_PLATFORM=MacOSX \                                                                                                                              
    APPLE_SDK_VERSION_OVERRIDE=15.2 \                                                                                                                        
    BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1 \                                                                                                                    
    PATH=/bin:/usr/bin:/usr/local/bin \                                                                                                                      
    XCODE_VERSION_OVERRIDE=16.2.0.16C5032a \                                                                                                                 
    ZERO_AR_DATE=1 \                                                                                                                                         
  external/apple_support++apple_cc_configure_extension+local_config_apple_cc/wrapped_clang_pp 
  '-D_FORTIFY_SOURCE=1' -fstack-protector -fcolor-diagnostics -Wall 
  -Wthread-safety -Wself-assign -fno-omit-frame-pointer -g0 -O2 -DNDEBUG
  '-DNS_BLOCK_ASSERTIONS=1' '-std=c++14'
  '-fdebug-prefix-map=__BAZEL_EXECUTION_ROOT__=.'
  '-fdebug-prefix-map=__BAZEL_XCODE_DEVELOPER_DIR__=/PLACEHOLDER_DEVELOPER_DIR'
  -iquote external/rules_java++toolchains+remote_java_tools
  -iquote bazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools
  -Ibazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_virtual_includes/filesystem
  -Ibazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_virtual_includes/blaze_exit_code
  -Ibazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_virtual_includes/errors
  -Ibazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_virtual_includes/logging
  -Ibazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_virtual_includes/strings
  -Ibazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_virtual_includes/port
  -MD -MF
  bazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_objs/filesystem/file_posix.d
  -DBLAZE_OPENSOURCE
  '-frandom-seed=bazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_objs/filesystem/file_posix.o'
  -isysroot __BAZEL_XCODE_SDKROOT__
  -F__BAZEL_XCODE_SDKROOT__/System/Library/Frameworks
  -F__BAZEL_XCODE_DEVELOPER_DIR__/Platforms/MacOSX.platform/Developer/Library/Frameworks
  -no-canonical-prefixes -pthread '-Werror=sign-compare' -g0 '-std=c++14'
  -fno-exceptions '-fvisibility=hidden' '-Werror=reorder'
  '-Werror=unused-function' '-Werror=return-type' '-Werror=sign-compare' -g0
  -no-canonical-prefixes -Wno-builtin-macro-redefined '-D__DATE__="redacted"'
  '-D__TIMESTAMP__="redacted"' '-D__TIME__="redacted"'
  -target arm64-apple-macosx15.2
  -c external/rules_java++toolchains+remote_java_tools/java_tools/src/main/cpp/util/file_posix.cc
  -o bazel-out/darwin_arm64-opt-exec-ST-d57f47055a04/bin/external/rules_java++toolchains+remote_java_tools/_objs/filesystem/file_posix.o)                                                                                       # Configuration: ...
# Execution platform: @@platforms//host:host                                                                                                                 

[fmeum]

@tjgq

[benjaminp]

6906ba6 added code that requires C++17.

[mbland]

6906ba6 added code that requires C++17.

Huh, can confirm it builds with: bazel build --cxxopt="-std=c++17" @remote_java_tools//:filesystem.

[mbland]

OK, we've been able to move forward by setting --cxxopt="-std=c++17" on all our platforms and having everything pass CI with rules_java 8.7.1 (and bazel_tools 13.14).

Feel free to close this if you think it's working as intended. For me, though, it's interesting that -std=c++14 breaks, and -std=c++17 doesn't. There appears to be a clear constness mismatch between std::string::data() and mkdtemp(), and I'd expect C++17 to be more strict. (If anyone can explain what I might be missing, I'd be delighted!)

[benjaminp]

C++17 specifies a non-const override of basic_string::data().

[mbland]

@benjaminp Ah, good to know—and a bit scary, but I guess it makes sense to enable easier adaptation to legacy C APIs without const_cast everywhere.