Skip to content

Commit

Permalink
Remove LLVM_ENABLE_TIMESTAMPS
Browse files Browse the repository at this point in the history
Summary:
As per the discussion on LLVM-dev this patch proposes removing LLVM_ENABLE_TIMESTAMPS.

The only complicated bit of this patch is the Windows support. On windows we used to log an error if /INCREMENTAL was passed to the linker when timestamps were disabled.

With this change since timestamps in code are always disabled we will always compile on windows with /Brepro unless /INCREMENTAL is specified, and we will log a warning when /INCREMENTAL is specified to notify the user that the build will be non-deterministic.

See: http://lists.llvm.org/pipermail/llvm-dev/2016-May/098990.html

Reviewers: bogner, silvas, rnk

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19892

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268670 91177308-0d34-0410-b5e6-96231b3b80d8
  • Loading branch information
Chris Bieneman committed May 5, 2016
1 parent d4c22d2 commit 6a6b44f
Show file tree
Hide file tree
Showing 5 changed files with 12 additions and 28 deletions.
5 changes: 0 additions & 5 deletions CMakeLists.txt
Original file line number Diff line number Diff line change
Expand Up @@ -249,11 +249,6 @@ set(LLVM_EXPERIMENTAL_TARGETS_TO_BUILD ""
option(BUILD_SHARED_LIBS
"Build all libraries as shared libraries instead of static" OFF)

option(LLVM_ENABLE_TIMESTAMPS "Enable embedding timestamp information in build" OFF)
if(LLVM_ENABLE_TIMESTAMPS)
set(ENABLE_TIMESTAMPS 1)
endif()

option(LLVM_ENABLE_BACKTRACES "Enable embedding backtraces on crash." ON)
if(LLVM_ENABLE_BACKTRACES)
set(ENABLE_BACKTRACES 1)
Expand Down
25 changes: 10 additions & 15 deletions cmake/modules/HandleLLVMOptions.cmake
Original file line number Diff line number Diff line change
Expand Up @@ -365,32 +365,29 @@ if( MSVC )
CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()

if (NOT LLVM_ENABLE_TIMESTAMPS AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
# clang-cl and cl by default produce non-deterministic binaries because
# link.exe /incremental requires a timestamp in the .obj file. clang-cl
# has the flag /Brepro to force deterministic binaries, so pass that when
# LLVM_ENABLE_TIMESTAMPS is turned off.
# has the flag /Brepro to force deterministic binaries. We want to pass that
# whenever you're building with clang unless you're passing /incremental.
# This checks CMAKE_CXX_COMPILER_ID in addition to check_cxx_compiler_flag()
# because cl.exe does not emit an error on flags it doesn't understand,
# letting check_cxx_compiler_flag() claim it understands all flags.
check_cxx_compiler_flag("/Brepro" SUPPORTS_BREPRO)
append_if(SUPPORTS_BREPRO "/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)

if (SUPPORTS_BREPRO)
# Check if /INCREMENTAL is passed to the linker and complain that it
# won't work with /Brepro.
string(TOUPPER "${CMAKE_EXE_LINKER_FLAGS}" upper_exe_flags)
string(TOUPPER "${CMAKE_MODULE_LINKER_FLAGS}" upper_module_flags)
string(TOUPPER "${CMAKE_SHARED_LINKER_FLAGS}" upper_shared_flags)

string(FIND "${upper_exe_flags}" "/INCREMENTAL" exe_index)
string(FIND "${upper_module_flags}" "/INCREMENTAL" module_index)
string(FIND "${upper_shared_flags}" "/INCREMENTAL" shared_index)
string(FIND "${upper_exe_flags} ${upper_module_flags} ${upper_shared_flags}"
"/INCREMENTAL" linker_flag_idx)

if (${exe_index} GREATER -1 OR
${module_index} GREATER -1 OR
${shared_index} GREATER -1)
message(FATAL_ERROR "LLVM_ENABLE_TIMESTAMPS not compatible with /INCREMENTAL linking")
if (${linker_flag_idx} GREATER -1)
message(WARNING "/Brepro not compatible with /INCREMENTAL linking - builds will be non-deterministic")
else()
append("/Brepro" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
endif()
endif()
endif()
Expand Down Expand Up @@ -456,9 +453,7 @@ elseif( LLVM_COMPILER_IS_GCC_COMPATIBLE )
endif()
endif (LLVM_ENABLE_WARNINGS)
append_if(LLVM_ENABLE_WERROR "-Werror" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
if (NOT LLVM_ENABLE_TIMESTAMPS)
add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
endif ()
add_flag_if_supported("-Werror=date-time" WERROR_DATE_TIME)
if (LLVM_ENABLE_CXX1Y)
check_cxx_compiler_flag("-std=c++1y" CXX_SUPPORTS_CXX1Y)
append_if(CXX_SUPPORTS_CXX1Y "-std=c++1y" CMAKE_CXX_FLAGS)
Expand Down
3 changes: 0 additions & 3 deletions include/llvm/Config/config.h.cmake
Original file line number Diff line number Diff line change
Expand Up @@ -16,9 +16,6 @@
/* Define if position independent code is enabled */
#cmakedefine ENABLE_PIC

/* Define if timestamp information (e.g., __DATE__) is allowed */
#cmakedefine ENABLE_TIMESTAMPS ${ENABLE_TIMESTAMPS}

/* Define to 1 if you have the `arc4random' function. */
#cmakedefine HAVE_DECL_ARC4RANDOM ${HAVE_DECL_ARC4RANDOM}

Expand Down
3 changes: 0 additions & 3 deletions lib/Support/CommandLine.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -1775,9 +1775,6 @@ class VersionPrinter {
if (CPU == "generic")
CPU = "(unknown)";
OS << ".\n"
#if (ENABLE_TIMESTAMPS == 1)
<< " Built " << __DATE__ << " (" << __TIME__ << ").\n"
#endif
<< " Default target: " << sys::getDefaultTargetTriple() << '\n'
<< " Host CPU: " << CPU << '\n';
}
Expand Down
4 changes: 2 additions & 2 deletions utils/release/test-release.sh
Original file line number Diff line number Diff line change
Expand Up @@ -375,13 +375,13 @@ function configure_llvmCore() {
echo "#" env CC="$c_compiler" CXX="$cxx_compiler" \
cmake -G "Unix Makefiles" \
-DCMAKE_BUILD_TYPE=$BuildType -DLLVM_ENABLE_ASSERTIONS=$Assertions \
-DLLVM_ENABLE_TIMESTAMPS=OFF -DLLVM_CONFIGTIME="(timestamp not enabled)" \
-DLLVM_CONFIGTIME="(timestamp not enabled)" \
$ExtraConfigureFlags $BuildDir/llvm.src \
2>&1 | tee $LogDir/llvm.configure-Phase$Phase-$Flavor.log
env CC="$c_compiler" CXX="$cxx_compiler" \
cmake -G "Unix Makefiles" \
-DCMAKE_BUILD_TYPE=$BuildType -DLLVM_ENABLE_ASSERTIONS=$Assertions \
-DLLVM_ENABLE_TIMESTAMPS=OFF -DLLVM_CONFIGTIME="(timestamp not enabled)" \
-DLLVM_CONFIGTIME="(timestamp not enabled)" \
$ExtraConfigureFlags $BuildDir/llvm.src \
2>&1 | tee $LogDir/llvm.configure-Phase$Phase-$Flavor.log
fi
Expand Down

0 comments on commit 6a6b44f

Please sign in to comment.