Test suite now handles emulated Thread-Local Storage for C++ attribute tests.
The GCC testsuite now correctly accounts for differences in output when testing C++ thread-local storage attributes with emulated TLS.
This commit updates GCC’s testsuite to include specific match criteria for emulated Thread-Local Storage (TLS) in C and C++ attribute tests. Previously, tests for TLS attributes might have failed when using emulated TLS because the generated output differs from that of native TLS implementations. By adding these adjustments to tls-attr-common.c, tls-attr-le-pic.c, and tls-attr-le-pie.c, the test suite now provides more accurate results across various TLS configurations, improving the reliability of attribute testing.
In Details
Thread-Local Storage (TLS) provides a mechanism for static or global variables to have distinct values for each thread. When the target architecture does not natively support TLS, the compiler toolchain provides an emulated implementation. This change adjusts the C/C++ test suite's expected output patterns when emulated TLS is active, particularly in tests involving attributes like __thread. The specific files, c-c++-common/tls-attr-common.c, tls-attr-le-pic.c, and tls-attr-le-pie.c, are part of the GCC test infrastructure that verifies correct handling of TLS, especially in PIC/PIE c…
For Context
In programs that use multiple threads (like a web browser with many tabs), sometimes a variable needs to have a unique value for each thread, even if it's declared globally. This is called Thread-Local Storage (TLS). Some computer processors have built-in support for TLS, while others don't. When there's no native support, the compiler and operating system have to \"emulate\" it using software tricks. This update to the GCC compiler's internal tests makes sure that when these software tricks are used for TLS, the compiler's output still matches what's expected. This helps ensure that programs using TLS work correctly on all kinds of computer systems.