build: better way to extract falco commit hash (also extract ref)

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

CMakeLists.txt

@@ -67,20 +67,33 @@ set(CMAKE_CXX_FLAGS_DEBUG "${DRAIOS_DEBUG_FLAGS}")
 set(CMAKE_C_FLAGS_RELEASE "-O3 -fno-strict-aliasing -DNDEBUG")
 set(CMAKE_CXX_FLAGS_RELEASE "-O3 -fno-strict-aliasing -DNDEBUG")
 
+add_definitions(-DPLATFORM_NAME="${CMAKE_SYSTEM_NAME}")
+add_definitions(-DK8S_DISABLE_THREAD)
+if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+  add_definitions(-DHAS_CAPTURE)
+endif()
+
+# Retrieve git ref and commit hash
+include(GetGitRevisionDescription)
+get_git_head_revision(FALCO_REF FALCO_HASH)
+
 # Create the falco version variable according to git index
 if(NOT FALCO_VERSION)
-  include(GetGitRevisionDescription)
+  string(STRIP "${FALCO_HASH}" FALCO_HASH)
+  # Try to obtain the exact git tag
   git_get_exact_tag(FALCO_TAG)
   if(NOT FALCO_TAG)
-    # Obtain the nearest tag
-    git_describe(FALCO_VERSION "--abbrev=0") # suppress the long format
-    # Obtain the git commit
-    git_describe(FALCO_VERSION_BUILD "--abbrev=7")
-    string(FIND "${FALCO_VERSION_BUILD}" "g" FALCO_VERSION_BUILD_START)
-    if(FALCO_VERSION_BUILD_START GREATER 0)
-      math(EXPR FALCO_VERSION_BUILD_START "${FALCO_VERSION_BUILD_START}+1")
-      string(SUBSTRING "${FALCO_VERSION_BUILD}"
-                       "${FALCO_VERSION_BUILD_START}"
+    # Obtain the closest tag
+    git_describe(FALCO_VERSION "--abbrev=0" "--tags") # suppress the long format
+    # Fallback version
+    if(FALCO_VERSION MATCHES "NOTFOUND$")
+      set(FALCO_VERSION "0.0.0")
+    endif()
+    # TODO(leodido) > Construct the prerelease part (semver 2) Construct the
+    # Build metadata part (semver 2)
+    if(NOT FALCO_HASH MATCHES "NOTFOUND$")
+      string(SUBSTRING "${FALCO_HASH}"
+                       0
                        7
                        FALCO_VERSION_BUILD)
       # Check whether there are uncommitted changes or not
@@ -90,9 +103,12 @@ if(NOT FALCO_VERSION)
         set(FALCO_VERSION_BUILD "${FALCO_VERSION_BUILD}.${FALCO_CHANGES}")
       endif()
     endif()
-    # Add build metadata part (semver 2)
+    # Append the build metadata part (semver 2)
+    if(FALCO_VERSION_BUILD)
       set(FALCO_VERSION "${FALCO_VERSION}+${FALCO_VERSION_BUILD}")
+    endif()
   else()
+    # A tag has been found: use it as the Falco version
     set(FALCO_VERSION "${FALCO_TAG}")
     # Remove the starting "v" in case there is one
     string(REGEX
@@ -101,24 +117,19 @@ if(NOT FALCO_VERSION)
                    FALCO_VERSION
                    "${FALCO_TAG}")
   endif()
+  # TODO(leodido) > ensure Falco version is semver before extracting parts
   # Populate partial version variables
-  string(
-    REGEX
-    MATCH
+  string(REGEX MATCH
                "^(0|[1-9][0-9]*)"
                FALCO_VERSION_MAJOR
                "${FALCO_VERSION}")
-  string(
-    REGEX
-    REPLACE
-      "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\..*"
+  string(REGEX
+         REPLACE "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\..*"
                  "\\2"
                  FALCO_VERSION_MINOR
                  "${FALCO_VERSION}")
-  string(
-    REGEX
-    REPLACE
-      "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*).*"
+  string(REGEX
+         REPLACE "^(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*)\\.(0|[1-9][0-9]*).*"
                  "\\3"
                  FALCO_VERSION_PATCH
                  "${FALCO_VERSION}")
@@ -133,10 +144,8 @@ if(NOT FALCO_VERSION)
     set(FALCO_VERSION_PRERELEASE "")
   endif()
   if(NOT FALCO_VERSION_BUILD)
-  string(
-    REGEX
-    REPLACE
-      ".*\\+([0-9a-zA-Z-]+(\\.[0-9a-zA-Z-]+)*)"
+    string(REGEX
+           REPLACE ".*\\+([0-9a-zA-Z-]+(\\.[0-9a-zA-Z-]+)*)"
                    "\\1"
                    FALCO_VERSION_BUILD
                    "${FALCO_VERSION}")

cmake/modules/GetGitRevisionDescription.cmake

@@ -104,18 +104,19 @@ function(git_describe _var)
     return()
   endif()
 
-  # TODO sanitize if((${ARGN}" MATCHES "&&") OR (ARGN MATCHES "||") OR (ARGN MATCHES "\\;")) message("Please report the
-  # following error to the project!") message(FATAL_ERROR "Looks like someone's doing something nefarious with
-  # git_describe! Passed arguments ${ARGN}") endif()
-
-  # message(STATUS "Arguments to execute_process: ${ARGN}")
-
-  execute_process(
-    COMMAND "${GIT_EXECUTABLE}" describe ${hash} ${ARGN}
-    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
-    RESULT_VARIABLE res
-    OUTPUT_VARIABLE out
-    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+  execute_process(COMMAND
+    "${GIT_EXECUTABLE}"
+    describe
+    ${hash}
+    ${ARGN}
+    WORKING_DIRECTORY
+    "${CMAKE_CURRENT_SOURCE_DIR}"
+    RESULT_VARIABLE
+    res
+    OUTPUT_VARIABLE
+    out
+    ERROR_QUIET
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
   if(NOT res EQUAL 0)
     set(out "${out}-${res}-NOTFOUND")
   endif()

userspace/falco/config_falco.h.in

@@ -16,6 +16,8 @@ limitations under the License.
 
 #pragma once
 
+#define FALCO_BRANCH "@FALCO_REF@"
+#define FALCO_HASH "@FALCO_HASH@"
 #define FALCO_VERSION "@FALCO_VERSION@"
 #define FALCO_VERSION_MAJOR "@FALCO_VERSION_MAJOR@"
 #define FALCO_VERSION_MINOR "@FALCO_VERSION_MINOR@"