[slachiewicz]

Jira: THRIFT-6522

An exception field named message generates getMessage(), which overrides Throwable.getMessage() and must return String. With any other type (a bool gets isMessage() and is fine) the generated Java never compiled. The Java generator now stops with an error naming the exception and the field, before writing any file.

IDL that used such a field produced uncompilable Java before, so no working build breaks.

Verified: thrift_compiler_tests "*named message" → fails on master (an i32 message field is not reported), 2 of 2 test cases pass on this branch; the full suite passes (42 test cases).

• Did you create an Apache Jira ticket?
• If a ticket exists: Does your pull request title follow the pattern "THRIFT-6522: describe my issue"?
• Did you squash your changes to a single commit?
• Did you do your best to avoid breaking changes? Only IDL whose generated Java could not compile is rejected.

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[Jens-G]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

Two suggestions, below the bar for an issue but verified:

• The "Build and run compiler tests on their own" step of cmake.yml does not build the new test. That step configures compiler/cpp/tests directly, where Java is still OFF, so java/*.c* is never globbed. Only the combined build in the same job runs it, because compiler/cpp/CMakeLists.txt turns THRIFT_COMPILER_JAVA on. compiler/cpp/tests/README.md asks to set the language to ON when adding tests, as is done for kotlin and the other languages with a test directory.

thrift/compiler/cpp/tests/CMakeLists.txt

Lines 130 to 132 in ba99031

	THRIFT_ADD_COMPILER(html "Enable compiler for HTML Documentation" OFF)
	THRIFT_ADD_COMPILER(java "Enable compiler for Java" OFF)
	THRIFT_ADD_COMPILER(javame "Enable compiler for Java ME" OFF)

• With java:option_type, exception E { 1: optional string message } still gets a getter that cannot override Throwable.getMessage(). The 0.25.0 compiler emits public org.apache.thrift.Option<java.lang.String> getMessage(), and java.util.Optional<java.lang.String> with option_type=jdk8. The new check accepts any string field named message, so that combination still yields Java that does not compile. It never compiled before either, so this is no regression, just one more case the check could reject.

thrift/compiler/cpp/src/thrift/generate/t_java_generator.cc

Lines 881 to 892 in ba99031

	if (is_exception) {
	// The getter of a field named "message" must override Throwable.getMessage(), which returns
	// String; a bool field gets isMessage() instead, and binary returns byte[].
	for (t_field* field : tstruct->get_members()) {
	t_type* type = get_true_type(field->get_type());
	if (get_cap_name(field->get_name()) == "Message" && !type->is_bool()
	&& !(type->is_string() && !type->is_binary())) {
	throw "exception " + tstruct->get_name() + ": field '" + field->get_name()
	+ "' must be a string or bool, because its getter would clash with"
	" Throwable.getMessage()";
	}
	}

🤖 Generated with Claude Code

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