cmake: make the use of split stack configureable
Add a CMake option GOLLVM_USE_SPLIT_STACK, default to true, to
control whether to use split stacks. This applies to both C and
Go compilations for the standard library.
llvm-goc's default is still split stack, regardless of this
setting. One needs to pass -fno-split-stack for user Go code
compilations.
Caveat: when using cgo, cmd/go may still by default pass
-fsplit-stack to the C compiler. Maybe a custom CC or CFLAGS
setting is needed to fully disable split stacks.
Change-Id: I6fd0471135b8061c4a2ff5331a7af263daceea84
Reviewed-on: https://go-review.googlesource.com/c/141678
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 86109ec..41ae721 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,6 +22,8 @@
# So that we can issue "make -jN" cmds in externalproject_add
processorcount(PROCESSOR_COUNT)
+set(GOLLVM_USE_SPLIT_STACK ON CACHE BOOL "use split stack by default")
+
set(EXTINSTALLDIR ${CMAKE_CURRENT_BINARY_DIR}/external/install)
set(EXTLIBDIR "${EXTINSTALLDIR}/lib")
set(EXTINCLUDEDIR "${EXTINSTALLDIR}/include")
diff --git a/cmake/modules/ConfigSetup.cmake b/cmake/modules/ConfigSetup.cmake
index 6763c1a..e6874f6 100644
--- a/cmake/modules/ConfigSetup.cmake
+++ b/cmake/modules/ConfigSetup.cmake
@@ -135,9 +135,11 @@
# Issue an error if the C compiler doesn't support -fsplit-stack
# (in theory you can build libgo without it, so I suppose this could
# be changed to a warning).
-check_c_compiler_flag("-fsplit-stack" C_SUPPORTS_SPLIT_STACK)
-if(NOT C_SUPPORTS_SPLIT_STACK)
- message(SEND_ERROR "C compiler does not support -fsplit-stack")
+if(GOLLVM_USE_SPLIT_STACK)
+ check_c_compiler_flag("-fsplit-stack" C_SUPPORTS_SPLIT_STACK)
+ if(NOT C_SUPPORTS_SPLIT_STACK)
+ message(SEND_ERROR "C compiler does not support -fsplit-stack")
+ endif()
+ set(USING_SPLIT_STACK 1)
endif()
-set(USING_SPLIT_STACK 1)
set(USE_LIBFFI 1)
diff --git a/cmake/modules/LibbacktraceUtils.cmake b/cmake/modules/LibbacktraceUtils.cmake
index 5489fc8..228f61b 100644
--- a/cmake/modules/LibbacktraceUtils.cmake
+++ b/cmake/modules/LibbacktraceUtils.cmake
@@ -61,7 +61,11 @@
"${libbacktrace_srcroot}/sort.c"
"${libbacktrace_srcroot}/state.c")
- set(libbacktraceflags "-fsplit-stack")
+ if(GOLLVM_USE_SPLIT_STACK)
+ set(libbacktraceflags "-fsplit-stack")
+ else()
+ set(libbacktraceflags "")
+ endif()
# Object libraries built from libbacktrace sources.
# Note: this build uses -fsplit-stack, whereas in the gccgo
diff --git a/gotools/CMakeLists.txt b/gotools/CMakeLists.txt
index 1d947dd..b7b9fd8 100644
--- a/gotools/CMakeLists.txt
+++ b/gotools/CMakeLists.txt
@@ -14,6 +14,9 @@
# Pick up any extra Go compiler flags specified via
# "cmake -DGOLLVM_EXTRA_GOCFLAGS=..."
set(gotools_extra_gocflags ${GOLLVM_EXTRA_GOCFLAGS})
+if(NOT GOLLVM_USE_SPLIT_STACK)
+ list(APPEND gotools_extra_gocflags "-fno-split-stack")
+endif()
# Driver for compiling *.go files.
get_target_property(driverdir llvm-goc RUNTIME_OUTPUT_DIRECTORY)
diff --git a/libgo/CMakeLists.txt b/libgo/CMakeLists.txt
index 9945d9c..821d171 100644
--- a/libgo/CMakeLists.txt
+++ b/libgo/CMakeLists.txt
@@ -58,9 +58,6 @@
file(COPY "${llvmconfigdir}/config.h" DESTINATION "llvm/Config")
file(COPY "${llvmconfigdir}/llvm-config.h" DESTINATION "llvm/Config")
-set(USING_SPLIT_STACK 1)
-set(USE_LIBFFI 1)
-
# Generate config.h, included by various C files in libgo/go/runtime
# and also used to emit gen-sysinfo.go.
file(MAKE_DIRECTORY "${libgo_binroot}/runtime")
@@ -82,6 +79,9 @@
# Pick up any extra Go compiler flags specified via
# "cmake -DGOLLVM_EXTRA_GOCFLAGS=..."
set(libgo_extra_gocflags ${GOLLVM_EXTRA_GOCFLAGS})
+if(NOT GOLLVM_USE_SPLIT_STACK)
+ list(APPEND libgo_extra_gocflags "-fno-split-stack")
+endif()
# Read in list of all libgo packages
file(STRINGS "${libgo_srcroot}/libgo-packages.txt" libpackages)
@@ -453,7 +453,10 @@
endforeach()
# Compiler flags for C files in the runtime.
-set(baseopts "-Wno-zero-length-array -fsplit-stack ")
+set(baseopts "-Wno-zero-length-array ")
+if(GOLLVM_USE_SPLIT_STACK)
+ string(APPEND baseopts "-fsplit-stack ")
+endif()
foreach(def ${basedefines})
string(APPEND baseopts "${def} ")
endforeach()
@@ -500,7 +503,11 @@
set_target_properties(libgo_shared PROPERTIES
LIBRARY_OUTPUT_DIRECTORY ${libgo_binroot})
set_target_properties(libgo_shared PROPERTIES OUTPUT_NAME "go")
-target_link_libraries(libgo_shared PUBLIC "-fsplit-stack;-lpthread;-lm")
+set(linkopts "-lpthread;-lm")
+if(GOLLVM_USE_SPLIT_STACK)
+ string(APPEND linkopts ";-fsplit-stack")
+endif()
+target_link_libraries(libgo_shared PUBLIC "${linkopts}")
# Sources for libgobegin.a
set(libgobegincfiles
