Hi, This patch simplifies how core runtime constructs the LibBacktrace object in the event of a segfault during unittests.
The core.runtime module always overrides the default parameter value for constructor calls. MaxAlignment is not required because a class can be created on the stack with the `scope' keyword. Bootstrapped and regression tested on x86_64-linux-gnu/-m32/-mx32, and committed to mainline. Regards Iain --- libphobos/ChangeLog: * libdruntime/core/runtime.d (runModuleUnitTests): Use scope to new LibBacktrace on the stack. * libdruntime/gcc/backtrace.d (FIRSTFRAME): Remove. (LibBacktrace.MaxAlignment): Remove. (LibBacktrace.this): Remove default initialization of firstFrame. (UnwindBacktrace.this): Likewise. --- libphobos/libdruntime/core/runtime.d | 14 +++----------- libphobos/libdruntime/gcc/backtrace.d | 24 ++---------------------- 2 files changed, 5 insertions(+), 33 deletions(-) diff --git a/libphobos/libdruntime/core/runtime.d b/libphobos/libdruntime/core/runtime.d index 848b607ae69..5fc99046d23 100644 --- a/libphobos/libdruntime/core/runtime.d +++ b/libphobos/libdruntime/core/runtime.d @@ -483,17 +483,9 @@ extern (C) bool runModuleUnitTests() fprintf(stderr, "Segmentation fault while running unittests:\n"); fprintf(stderr, "----------------\n"); - enum alignment = LibBacktrace.MaxAlignment; - enum classSize = __traits(classInstanceSize, LibBacktrace); - - void[classSize + alignment] bt_store = void; - void* alignedAddress = cast(byte*)((cast(size_t)(bt_store.ptr + alignment - 1)) - & ~(alignment - 1)); - - (alignedAddress[0 .. classSize]) = typeid(LibBacktrace).initializer[]; - auto bt = cast(LibBacktrace)(alignedAddress); - // First frame is LibBacktrace ctor. Second is signal handler, but include that for now - bt.__ctor(1); + // First frame is LibBacktrace ctor. Second is signal handler, + // but include that for now + scope bt = new LibBacktrace(1); foreach (size_t i, const(char[]) msg; bt) fprintf(stderr, "%s\n", msg.ptr ? msg.ptr : "???"); diff --git a/libphobos/libdruntime/gcc/backtrace.d b/libphobos/libdruntime/gcc/backtrace.d index 8f5582d7469..3c4d65f417f 100644 --- a/libphobos/libdruntime/gcc/backtrace.d +++ b/libphobos/libdruntime/gcc/backtrace.d @@ -24,24 +24,6 @@ module gcc.backtrace; import gcc.libbacktrace; -version (Posix) -{ - // NOTE: The first 5 frames with the current implementation are - // inside core.runtime and the object code, so eliminate - // these for readability. The alternative would be to - // exclude the first N frames that are in a list of - // mangled function names. - private enum FIRSTFRAME = 5; -} -else -{ - // NOTE: On Windows, the number of frames to exclude is based on - // whether the exception is user or system-generated, so - // it may be necessary to exclude a list of function names - // instead. - private enum FIRSTFRAME = 0; -} - // Max size per line of the traceback. private enum MAX_BUFSIZE = 1536; @@ -205,8 +187,6 @@ static if (BACKTRACE_SUPPORTED && !BACKTRACE_USES_MALLOC) // FIXME: state is never freed as libbacktrace doesn't provide a free function... public class LibBacktrace : Throwable.TraceInfo { - enum MaxAlignment = (void*).alignof; - static void initLibBacktrace() { if (!initialized) @@ -216,7 +196,7 @@ static if (BACKTRACE_SUPPORTED && !BACKTRACE_USES_MALLOC) } } - this(int firstFrame = FIRSTFRAME) + this(int firstFrame) { _firstFrame = firstFrame; @@ -365,7 +345,7 @@ else */ public class UnwindBacktrace : Throwable.TraceInfo { - this(int firstFrame = FIRSTFRAME) + this(int firstFrame) { _firstFrame = firstFrame; _callstack = getBacktrace(); -- 2.30.2