From 714d5079387ebe88d0c7a77a69eb0df3d54b91b6 Mon Sep 17 00:00:00 2001 From: Yuri Kunde Schlesner Date: Wed, 18 Feb 2015 02:06:48 -0200 Subject: Asserts: Use lambdas to keep assertion code away from the main code path --- src/common/assert.h | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) (limited to 'src/common/assert.h') diff --git a/src/common/assert.h b/src/common/assert.h index 3b2232a7..9ca7adb1 100644 --- a/src/common/assert.h +++ b/src/common/assert.h @@ -4,24 +4,43 @@ #pragma once +#include + #include "common/common_funcs.h" +// For asserts we'd like to keep all the junk executed when an assert happens away from the +// important code in the function. One way of doing this is to put all the relevant code inside a +// lambda and force the compiler to not inline it. Unfortunately, MSVC seems to have no syntax to +// specify __declspec on lambda functions, so what we do instead is define a noinline wrapper +// template that calls the lambda. This seems to generate an extra instruction at the call-site +// compared to the ideal implementation (which wouldn't support ASSERT_MSG parameters), but is good +// enough for our purposes. +template +#if defined(_MSC_VER) + __declspec(noinline, noreturn) +#elif defined(__GNUC__) + __attribute__((noinline, noreturn, cold)) +#endif +static void assert_noinline_call(const Fn& fn) { + fn(); + Crash(); + exit(1); // Keeps GCC's mouth shut about this actually returning +} + // TODO (yuriks) allow synchronous logging so we don't need printf #define ASSERT(_a_) \ - do if (!(_a_)) {\ + do if (!(_a_)) { assert_noinline_call([] { \ fprintf(stderr, "Assertion Failed!\n\n Line: %d\n File: %s\n Time: %s\n", \ __LINE__, __FILE__, __TIME__); \ - Crash(); \ - } while (0) + }); } while (0) #define ASSERT_MSG(_a_, ...) \ - do if (!(_a_)) {\ + do if (!(_a_)) { assert_noinline_call([&] { \ fprintf(stderr, "Assertion Failed!\n\n Line: %d\n File: %s\n Time: %s\n", \ __LINE__, __FILE__, __TIME__); \ fprintf(stderr, __VA_ARGS__); \ fprintf(stderr, "\n"); \ - Crash(); \ - } while (0) + }); } while (0) #define UNREACHABLE() ASSERT_MSG(false, "Unreachable code!") -- cgit v1.2.3