GCC Support for Linux

Updates and fixes to support GCC for Linux

Signed-off-by: Steve Pham <82231385+spham-amzn@users.noreply.github.com>

Co-authored-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>

scripts/build/Platform/Linux/build_config.json

@@ -58,6 +58,21 @@
       "CMAKE_TARGET": "all"
     }
   },
+  "profile_gcc_nounity": {
+    "TAGS": [
+      "nightly-incremental",
+      "nightly-clean"
+    ],
+    "COMMAND": "build_linux.sh",
+    "PARAMETERS": {
+      "CONFIGURATION": "profile",
+      "OUTPUT_DIRECTORY": "build/linux_gcc",
+      "CMAKE_OPTIONS": "-G 'Ninja Multi-Config' -DLY_UNITY_BUILD=FALSE -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DLY_PARALLEL_LINK_JOBS=4 -DLY_GCC_BUILD_FOR_GCOV=OFF",
+      "CMAKE_LY_PROJECTS": "AutomatedTesting",
+      "CMAKE_TARGET": "all",
+      "LY_MIN_MEMORY_PER_CORE": "2097152"
+    }
+ },
   "profile_nounity": {
     "TAGS": [
       "weekly-build-metrics"
@@ -87,6 +102,23 @@
       "TEST_RESULTS": "False"
     }
   },
+  "test_profile_gcc_nounity": {
+    "TAGS": [
+      "nightly-incremental",
+      "nightly-clean"
+    ],
+    "COMMAND": "build_test_linux.sh",
+    "PARAMETERS": {
+      "CONFIGURATION": "profile",
+      "OUTPUT_DIRECTORY": "build/linux_gcc",
+      "CMAKE_OPTIONS": "-G 'Ninja Multi-Config' -DLY_UNITY_BUILD=FALSE -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DLY_PARALLEL_LINK_JOBS=4 -DLY_GCC_BUILD_FOR_GCOV=ON",
+      "CMAKE_LY_PROJECTS": "AutomatedTesting",
+      "CMAKE_TARGET": "all",
+      "CTEST_OPTIONS": "-E (AutomatedTesting::Atom_TestSuite_Main|AutomatedTesting::TerrainTests_Main|Gem::EMotionFX.Editor.Tests) -L (SUITE_smoke|SUITE_main) -LE (REQUIRES_gpu) --no-tests=error",
+      "TEST_RESULTS": "False",
+      "LY_MIN_MEMORY_PER_CORE": "2097152"
+    }
+  },
   "test_profile_nounity": {
     "TAGS": [],
     "COMMAND": "build_test_linux.sh",

scripts/build/Platform/Linux/build_linux.sh

@@ -43,7 +43,30 @@ if [[ ! -z "$RUN_CONFIGURE" ]]; then
     echo "${CONFIGURE_CMD}" > ${LAST_CONFIGURE_CMD_FILE}
 fi
 
-eval echo [ci_build] cmake --build . --target ${CMAKE_TARGET} --config ${CONFIGURATION} -j $(grep -c processor /proc/cpuinfo) -- ${CMAKE_NATIVE_BUILD_ARGS}
-eval cmake --build . --target ${CMAKE_TARGET} --config ${CONFIGURATION} -j $(grep -c processor /proc/cpuinfo) -- ${CMAKE_NATIVE_BUILD_ARGS}
+TOTAL_MEMORY=$(cat /proc/meminfo | grep MemTotal | awk '{print $2}')
+TOTAL_CORE_COUNT=$(grep -c processor /proc/cpuinfo)
+echo "Total Memory        : $TOTAL_MEMORY kB"
+echo "Total Cores         : $TOTAL_CORE_COUNT"
+
+# For machines that has a core to memory ratio that could cause running out of resources, 
+# we will check for an environment variable LY_MIN_MEMORY_PER_CORE to restrict the number
+# of cores that we will allow.  If set, it will use this as the minimum anticipated memory
+# that all cores will need in order to no fall below that number. 
+#
+# This is based on the value the total memory (in kB) divided by the LY_MIN_MEMORY_PER_CORE 
+# (in kB, e.g. 2 GB = 2097152 kB)
+
+if [[ "${LY_MIN_MEMORY_PER_CORE:-0}" -gt 0 ]]; then
+    MIN_MEMORY_PER_CORE=${LY_MIN_MEMORY_PER_CORE}
+    CALCULATED_MAX_CORE_USAGE=$(expr $TOTAL_MEMORY / $MIN_MEMORY_PER_CORE - 1)
+    CORE_COUNT=$((CALCULATED_MAX_CORE_USAGE > TOTAL_CORE_COUNT ? TOTAL_CORE_COUNT :  CALCULATED_MAX_CORE_USAGE))
+    echo "Max Usable Cores    : $CORE_COUNT"
+else
+    CORE_COUNT=$TOTAL_CORE_COUNT
+fi
+
+
+eval echo [ci_build] cmake --build . --target ${CMAKE_TARGET} --config ${CONFIGURATION} -j $CORE_COUNT -- ${CMAKE_NATIVE_BUILD_ARGS}
+eval cmake --build . --target ${CMAKE_TARGET} --config ${CONFIGURATION} -j $CORE_COUNT -- ${CMAKE_NATIVE_BUILD_ARGS}
 
 popd