Change installation instructions to install libunwind locally

Also, set -Wno-extern-c-compat to silence libunwind-related warnings.
Fixes #27, hopefully for real this time.

docs/INSTALLING.md

@@ -59,10 +59,12 @@ There seem to be some lingering issues with the LLVM build that haven't been ide
 cd ~/pyston_deps
 wget http://download.savannah.gnu.org/releases/libunwind/libunwind-1.1.tar.gz
 tar xvf libunwind-1.1.tar.gz
+mkdir libunwind-1.1-install
 cd libunwind-1.1
-./configure
+# disable shared libraries because we'll be installing this in a place that the loader can't find it.
+./configure --prefix=$HOME/pyston_deps/libunwind-1.1-install --enable-shared=0
 make -j4
-sudo make install
+make install
 ```
 
 TODO would be nice to install this locally like the rest of the dependencies

src/Makefile

@@ -121,6 +121,12 @@ COMMON_CXXFLAGS += -Wno-unused-parameter # should use the "unused" attribute
 # Or everything:
 # COMMON_CXXFLAGS += -Weverything
 
+# libunwind's include files warn on -Wextern-c-compat, so turn that off;
+# ideally would just turn it off for header files in libunwind, maybe by
+# having an internal libunwind.h that pushed/popped the diagnostic state,
+# but it doesn't seem like that important a warning so just turn it off.
+COMMON_CXXFLAGS += -I$(DEPS_DIR)/libunwind-1.1-install/include -Wno-extern-c-compat
+
 COMMON_CXXFLAGS += -DGITREV=$(shell git rev-parse HEAD | head -c 12) -DLLVMREV=$(LLVM_REVISION)
 COMMON_CXXFLAGS += -DDEFAULT_PYTHON_MAJOR_VERSION=$(PYTHON_MAJOR_VERSION) -DDEFAULT_PYTHON_MINOR_VERSION=$(PYTHON_MINOR_VERSION) -DDEFAULT_PYTHON_MICRO_VERSION=$(PYTHON_MICRO_VERSION)
 
@@ -134,6 +140,8 @@ COMMON_LDFLAGS := -B../tools/build_system -L/usr/local/lib -lpthread -ldl -lcurs
 # TODO should probably do the linking before MCJIT
 COMMON_LDFLAGS += -Wl,-E
 
+COMMON_LDFLAGS += -L$(DEPS_DIR)/libunwind-1.1-install/lib
+
 # The system libstdc++ will likely be too old for Pyston, but we made a brand new one
 # as part of our GCC installation.  There are a couple ways to use that one instead:
 # 1) Install the built libstdc++ (~/pyston_deps/gcc-4.8.2-install/lib64/libstdc++.so.6.0.18) and update the global shared library (/usr/local/x86_64-linux-gnu/libstdc++.so.6) to point to it

src/runtime/stacktrace.cpp

@@ -13,18 +13,8 @@
 // limitations under the License.
 
 #define UNW_LOCAL_ONLY
-
-#ifdef __clang__
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wextern-c-compat"
-#endif
-
 #include <libunwind.h>
 
-#ifdef __clang__
-#pragma clang diagnostic pop
-#endif
-
 
 #include "core/options.h"