[llvm] 112aafc - Revert "Add a cmake flag to turn `llvm_unreachable()` into builtin_trap() when assertions are disabled"
Nikita Popov via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 18 01:22:03 PDT 2022
Author: Nikita Popov
Date: 2022-03-18T09:21:53+01:00
New Revision: 112aafcaf425dca901690ca823d25607e5795263
URL: https://github.com/llvm/llvm-project/commit/112aafcaf425dca901690ca823d25607e5795263
DIFF: https://github.com/llvm/llvm-project/commit/112aafcaf425dca901690ca823d25607e5795263.diff
LOG: Revert "Add a cmake flag to turn `llvm_unreachable()` into builtin_trap() when assertions are disabled"
This reverts commit 6316129e066e0a252430699f2b41706d4808476c.
This was implemented with inverted logic.
Added:
Modified:
llvm/CMakeLists.txt
llvm/docs/CMake.rst
llvm/include/llvm/Config/llvm-config.h.cmake
llvm/include/llvm/Support/ErrorHandling.h
Removed:
################################################################################
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 988c77b68c937..9892c6cd2c515 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -465,7 +465,6 @@ option(LLVM_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
option(LLVM_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
option(LLVM_ENABLE_DUMP "Enable dump functions even when assertions are disabled" OFF)
-option(LLVM_UNREACHABLE_OPTIMIZE "Optimize llvm_unreachable() as undefined behavior (default), guaranteed trap when OFF" ON)
if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
option(LLVM_ENABLE_ASSERTIONS "Enable assertions" OFF)
diff --git a/llvm/docs/CMake.rst b/llvm/docs/CMake.rst
index 4f5a0bb3617c1..ac635fc7df885 100644
--- a/llvm/docs/CMake.rst
+++ b/llvm/docs/CMake.rst
@@ -300,12 +300,6 @@ enabled sub-projects. Nearly all of these variable names begin with
enabled or not. A version of LLVM built with ABI breaking checks
is not ABI compatible with a version built without it.
-**LLVM_UNREACHABLE_OPTIMIZE**:BOOL
- This flag controls the behavior of `llvm_unreachable()` in release build
- (when assertions are disabled in general). When ON (default) then
- `llvm_unreachable()` is considered "undefined behavior" and optimized as
- such. When OFF it is instead replaced with a guaranteed "trap".
-
**LLVM_APPEND_VC_REV**:BOOL
Embed version control revision info (Git revision id).
The version info is provided by the ``LLVM_REVISION`` macro in
diff --git a/llvm/include/llvm/Config/llvm-config.h.cmake b/llvm/include/llvm/Config/llvm-config.h.cmake
index f8281d8297929..d8edf33ba0ce1 100644
--- a/llvm/include/llvm/Config/llvm-config.h.cmake
+++ b/llvm/include/llvm/Config/llvm-config.h.cmake
@@ -112,8 +112,4 @@
/* Define if building LLVM with LLVM_FORCE_USE_OLD_TOOLCHAIN_LIBS */
#cmakedefine LLVM_FORCE_USE_OLD_TOOLCHAIN ${LLVM_FORCE_USE_OLD_TOOLCHAIN}
-/* Define if llvm_unreachable should be optimized with undefined behavior
- * in non assert builds */
-#cmakedefine01 LLVM_UNREACHABLE_OPTIMIZE
-
#endif
diff --git a/llvm/include/llvm/Support/ErrorHandling.h b/llvm/include/llvm/Support/ErrorHandling.h
index 8d518365eb5bc..f980510d37f06 100644
--- a/llvm/include/llvm/Support/ErrorHandling.h
+++ b/llvm/include/llvm/Support/ErrorHandling.h
@@ -124,23 +124,15 @@ llvm_unreachable_internal(const char *msg = nullptr, const char *file = nullptr,
/// Marks that the current location is not supposed to be reachable.
/// In !NDEBUG builds, prints the message and location info to stderr.
-/// In NDEBUG builds, the behavior is controlled by the CMake flag
-/// -DLLVM_UNREACHABLE_OPTIMIZE
-/// * When "ON" (default) llvm_unreachable() becomes an optimizer hint
-/// that the current location is not supposed to be reachable: the hint
-/// turns such code path into undefined behavior. On compilers that don't
-/// support such hints, prints a reduced message instead and aborts the
-/// program.
-/// * When "OFF", a builtin_trap is emitted instead of an
-// optimizer hint or printing a reduced message.
+/// In NDEBUG builds, becomes an optimizer hint that the current location
+/// is not supposed to be reachable. On compilers that don't support
+/// such hints, prints a reduced message instead and aborts the program.
///
/// Use this instead of assert(0). It conveys intent more clearly and
/// allows compilers to omit some unnecessary code.
#ifndef NDEBUG
#define llvm_unreachable(msg) \
::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__)
-#elif LLVM_UNREACHABLE_OPTIMIZE
-#define llvm_unreachable(msg) LLVM_BUILTIN_TRAP
#elif defined(LLVM_BUILTIN_UNREACHABLE)
#define llvm_unreachable(msg) LLVM_BUILTIN_UNREACHABLE
#else
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