From 4cc2b292c0cc8759da7a525e63dbfefdb06d6a01 Mon Sep 17 00:00:00 2001
From: Dan Liew <daniel.liew@imperial.ac.uk>
Date: Fri, 28 Apr 2017 17:59:04 +0100
Subject: [PATCH] [CMake] Remove compiler flag overrides and support for C
 language.

The setting of overrides was broken (the CXX flags were not set but
the C flags were) and we aren't even using the C compiler any more.

The C compiler is used by the example C project but that is built
as an external project now so we don't need C support anymore.

The setting of defaults was also very fragile. CMake has quite
complicated support here (e.g. MSVC with a clang based tool chain) which
would likely not work properly with the override approach as it existed.

This means we loose some of the custom linker flags we were setting for
MSVC but we were never doing a great job of replicating the exact set of
flags used in the old build system anyway. Subsequent commits will
gradually fix this.
---
 CMakeLists.txt                                |  4 +-
 .../cmake/cmake/compiler_flags_override.cmake | 43 -------------------
 2 files changed, 1 insertion(+), 46 deletions(-)
 delete mode 100644 contrib/cmake/cmake/compiler_flags_override.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 47a081e75..ab3976aea 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,9 +24,7 @@ if (NOT (EXISTS "${CMAKE_SOURCE_DIR}/src/CMakeLists.txt"))
           "``python contrib/cmake/bootstrap.py create``")
 endif()
 
-# This overrides the default flags for the different CMAKE_BUILD_TYPEs
-set(CMAKE_USER_MAKE_RULES_OVERRIDE "${CMAKE_CURRENT_SOURCE_DIR}/cmake/compiler_flags_override.cmake")
-project(Z3 C CXX)
+project(Z3 CXX)
 
 ################################################################################
 # Project version
diff --git a/contrib/cmake/cmake/compiler_flags_override.cmake b/contrib/cmake/cmake/compiler_flags_override.cmake
deleted file mode 100644
index c6005396b..000000000
--- a/contrib/cmake/cmake/compiler_flags_override.cmake
+++ /dev/null
@@ -1,43 +0,0 @@
-# This file overrides the default compiler flags for CMake's built-in
-# configurations (CMAKE_BUILD_TYPE). Most compiler flags should not be set here.
-# The main purpose is to have very fine grained control of the compiler flags.
-if (CMAKE_C_COMPILER_ID)
-  set(_lang C)
-elseif(CMAKE_CXX_COMPILER_ID)
-  set(_lang CXX)
-else()
-  message(FATAL_ERROR "Unknown language")
-endif()
-
-# TODO: The value of doing this is debatable. The flags set here are pretty
-# much the CMake defaults now (they didn't use to be) and makes extra work for
-# us when supporting different compilers. Perhaps we should move the remaining
-# code that sets non-default flags out into the CMakeLists.txt files and remove
-# any overrides here?
-if (("${CMAKE_${_lang}_COMPILER_ID}" MATCHES "Clang") OR ("${CMAKE_${_lang}_COMPILER_ID}" MATCHES "GNU"))
-  # Taken from Modules/Compiler/GNU.cmake
-  set(CMAKE_${_lang}_FLAGS_INIT "")
-  set(CMAKE_${_lang}_FLAGS_DEBUG_INIT "-g -O0")
-  set(CMAKE_${_lang}_FLAGS_MINSIZEREL_INIT "-Os -DNDEBUG")
-  set(CMAKE_${_lang}_FLAGS_RELEASE_INIT "-O3 -DNDEBUG")
-  set(CMAKE_${_lang}_FLAGS_RELWITHDEBINFO_INIT "-O2 -g -DNDEBUG")
-  # FIXME: Remove "x.." when CMP0054 is set to NEW
-elseif ("x${CMAKE_${_lang}_COMPILER_ID}" STREQUAL "xMSVC")
-  # FIXME: Perhaps we should be using /MD instead?
-  set(CMAKE_${_lang}_FLAGS_DEBUG_INIT "/MTd /Zi /Ob0 /Od /RTC1")
-  set(CMAKE_${_lang}_FLAGS_MINSIZEREL_INIT     "/MT /O1 /Ob1 /D NDEBUG")
-  set(CMAKE_${_lang}_FLAGS_RELEASE_INIT        "/MT /O2 /Ob2 /D NDEBUG")
-  set(CMAKE_${_lang}_FLAGS_RELWITHDEBINFO_INIT "/MT /Zi /O2 /Ob1 /D NDEBUG")
-  # Override linker flags (see Windows-MSVC.cmake for CMake's defaults)
-  # The stack size comes from the Python build system.
-  set(_msvc_stack_size "8388608")
-  set(CMAKE_EXE_LINKER_FLAGS_DEBUG_INIT "/debug /INCREMENTAL:NO /STACK:${_msvc_stack_size}")
-  set(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO_INIT "/debug /INCREMENTAL:NO /STACK:${_msvc_stack_size}")
-  set(CMAKE_EXE_LINKER_FLAGS_MINSIZEREL_INIT "/INCREMENTAL:NO /STACK:${_msvc_stack_size}")
-  set(CMAKE_EXE_LINKER_FLAGS_RELEASE_INIT "/INCREMENTAL:NO /STACK:${_msvc_stack_size}")
-  unset(_msvc_stack_size)
-else()
-  message(FATAL_ERROR "Overrides not set for ${_lang} compiler \"${CMAKE_${_lang}_COMPILER_ID}\"")
-endif()
-
-unset(_lang)