Split checkout and build on Travis CI.

Seems to be getting timeouts.

.travis.yml

@@ -8,14 +8,11 @@ osx_image: xcode8.3
 sudo: required
 dist: trusty
 
-# We check out glslang and SPIRV-Tools at specific revisions to avoid test output mismatches
-env:
-  - PROFILE=plain
-
 before_script:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew upgrade python3; fi
+  - ./checkout_glslang_spirv_tools.sh
 
 script:
-  - ./checkout_glslang_spirv_tools.sh
+  - ./build_glslang_spirv_tools.sh
   - make -j2
   - ./test_shaders.sh

build_glslang_spirv_tools.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+echo "Building glslang."
+mkdir -p external/glslang-build
+cd external/glslang-build
+cmake ../glslang -DCMAKE_BUILD_TYPE=Release -G"Unix Makefiles"
+make -j$(nproc)
+cd ../..
+
+echo "Building SPIRV-Tools."
+mkdir -p external/spirv-tools-build
+cd external/spirv-tools-build
+cmake ../spirv-tools -DCMAKE_BUILD_TYPE=Release -G"Unix Makefiles"
+make -j$(nproc)
+cd ../..
+

checkout_glslang_spirv_tools.sh

@@ -18,13 +18,6 @@ else
 fi
 cd ../..
 
-echo "Building glslang."
-mkdir -p external/glslang-build
-cd external/glslang-build
-cmake ../glslang -DCMAKE_BUILD_TYPE=Release -G"Unix Makefiles"
-make -j$(nproc)
-cd ../..
-
 if [ -d external/spirv-tools ]; then
 	echo "Updating SPIRV-Tools to revision $SPIRV_TOOLS_REV."
 	cd external/spirv-tools
@@ -49,10 +42,3 @@ fi
 
 cd ../..
 
-echo "Building SPIRV-Tools."
-mkdir -p external/spirv-tools-build
-cd external/spirv-tools-build
-cmake ../spirv-tools -DCMAKE_BUILD_TYPE=Release -G"Unix Makefiles"
-make -j$(nproc)
-cd ../..
-