build: refactor ability to include prometheus text decoder

Signed-off-by: Eduardo Silva <[email protected]>

Author: edsiper

CMakeLists.txt

@@ -68,11 +68,11 @@ else()
 endif()
 
 # Configuration options
-option(CMT_DEV                       "Enable development mode"                   No)
-option(CMT_DEBUG                     "Enable debug mode"                         No)
-option(CMT_TESTS                     "Enable unit testing"                       No)
+option(CMT_DEV                       "Enable development mode"                    No)
+option(CMT_DEBUG                     "Enable debug mode"                          No)
+option(CMT_TESTS                     "Enable unit testing"                        No)
 option(CMT_INSTALL_TARGETS           "Enable subdirectory library installations" Yes)
-option(CMT_ENABLE_PROMETHEUS_DECODER "Enable prometheus decoder"                 Yes)
+option(CMT_PROMETHEUS_TEXT_DECODER   "Enable prometheus text format decoder (requires Flex/Bison)" Yes)
 
 if(CMT_DEV)
   set(CMT_TESTS   Yes)
@@ -155,7 +155,7 @@ check_c_source_compiles("
      return 0;
   }" CMT_HAVE_MSGPACK)
 
-if(CMT_ENABLE_PROMETHEUS_DECODER)
+if(CMT_PROMETHEUS_TEXT_DECODER)
     # Flex and Bison: check if the variables has not been defined before by
     # a parent project to avoid conflicts.
     if(NOT FLEX_FOUND)
@@ -167,7 +167,8 @@ if(CMT_ENABLE_PROMETHEUS_DECODER)
     endif()
 
     if(FLEX_FOUND AND BISON_FOUND)
-        set(CMT_BUILD_PROMETHEUS_DECODER 1)
+        set(CMT_BUILD_PROMETHEUS_TEXT_DECODER 1)
+        CMT_DEFINITION(CMT_HAVE_PROMETHEUS_TEXT_DECODER)
     endif()
 endif()
 

include/CMakeLists.txt

@@ -1,8 +1,25 @@
+# Install headers conditionally based on Prometheus text decoder availability
 file(GLOB cmetricsHeaders "cmetrics/*.h")
-install(FILES ${cmetricsHeaders}
-    DESTINATION ${CMT_INSTALL_INCLUDEDIR}/cmetrics
-    COMPONENT headers
-    PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)
+
+if(CMT_BUILD_PROMETHEUS_TEXT_DECODER)
+    # Install all headers when Prometheus text decoder is enabled
+    install(FILES ${cmetricsHeaders}
+        DESTINATION ${CMT_INSTALL_INCLUDEDIR}/cmetrics
+        COMPONENT headers
+        PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)
+else()
+    # Install headers except Prometheus text decoder header when disabled
+    # (remote write decoder header is always installed)
+    foreach(header ${cmetricsHeaders})
+        get_filename_component(header_name ${header} NAME)
+        if(NOT header_name STREQUAL "cmt_decode_prometheus.h")
+            install(FILES ${header}
+                DESTINATION ${CMT_INSTALL_INCLUDEDIR}/cmetrics
+                COMPONENT headers
+                PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ)
+        endif()
+    endforeach()
+endif()
 
 file(GLOB promHeaders "prometheus_remote_write/*.h")
 install(FILES ${promHeaders}

include/cmetrics/cmt_decode_prometheus.h

@@ -20,6 +20,10 @@
 #ifndef CMT_DECODE_PROMETHEUS_H
 #define CMT_DECODE_PROMETHEUS_H
 
+#include <cmetrics/cmt_info.h>
+
+#ifdef CMT_HAVE_PROMETHEUS_TEXT_DECODER
+
 #include <stdbool.h>
 
 #include <cmetrics/cmetrics.h>
@@ -110,4 +114,6 @@ int cmt_decode_prometheus_create(
         struct cmt_decode_prometheus_parse_opts *opts);
 void cmt_decode_prometheus_destroy(struct cmt *cmt);
 
+#endif /* CMT_HAVE_PROMETHEUS_TEXT_DECODER */
+
 #endif

src/CMakeLists.txt

@@ -1,4 +1,4 @@
-if (CMT_BUILD_PROMETHEUS_DECODER)
+if (CMT_BUILD_PROMETHEUS_TEXT_DECODER)
     flex_target(cmt_decode_prometheus_lexer cmt_decode_prometheus.l
         "${FLEX_BISON_GENERATED_DIR}/cmt_decode_prometheus_lexer.c"
         DEFINES_FILE "${FLEX_BISON_GENERATED_DIR}/cmt_decode_prometheus_lexer.h"
@@ -28,7 +28,6 @@ set(src
   cmt_decode_opentelemetry.c
   cmt_encode_prometheus.c
   cmt_encode_prometheus_remote_write.c
-  cmt_decode_prometheus_remote_write.c
   cmt_encode_splunk_hec.c
   cmt_encode_cloudwatch_emf.c
   cmt_encode_text.c
@@ -37,12 +36,16 @@ set(src
   cmt_decode_msgpack.c
   cmt_decode_statsd.c
   cmt_mpack_utils.c
-
-  # Prometheus related protobuf files
-  external/remote.pb-c.c
-  external/types.pb-c.c
   )
 
+# Add Prometheus remote write decoder (always available, only needs protobuf)
+set(src ${src}
+    cmt_decode_prometheus_remote_write.c
+    # Prometheus related protobuf files
+    external/remote.pb-c.c
+    external/types.pb-c.c
+    )
+
 
 if (MSVC)
   set(PLATFORM_SPECIFIC_ATOMIC_MODULE cmt_atomic_msvc.c)
@@ -63,7 +66,7 @@ set(src
   ${PLATFORM_SPECIFIC_ATOMIC_MODULE}
   )
 
-if (CMT_BUILD_PROMETHEUS_DECODER)
+if (CMT_BUILD_PROMETHEUS_TEXT_DECODER)
     set(src ${src}
         ${FLEX_cmt_decode_prometheus_lexer_OUTPUTS}
         ${BISON_cmt_decode_prometheus_parser_OUTPUTS}

tests/CMakeLists.txt

@@ -14,7 +14,7 @@ set(UNIT_TESTS_FILES
   filter.c
   )
 
-if (CMT_BUILD_PROMETHEUS_DECODER)
+if (CMT_BUILD_PROMETHEUS_TEXT_DECODER)
     set(UNIT_TESTS_FILES
         ${UNIT_TESTS_FILES}
         prometheus_lexer.c

tests/issues.c

@@ -91,6 +91,8 @@ void test_issue_54()
     cmt_destroy(cmt1);
 }
 
+#ifdef CMT_HAVE_PROMETHEUS_TEXT_DECODER
+
 /* issue: https://github.com/fluent/fluent-bit/issues/10761 */
 void test_prometheus_metric_no_subsystem()
 {
@@ -117,8 +119,12 @@ void test_prometheus_metric_no_subsystem()
     }
 }
 
+#endif
+
 TEST_LIST = {
     {"issue_54", test_issue_54},
+#ifdef CMT_HAVE_PROMETHEUS_TEXT_DECODER
     {"prometheus_metric_no_subsystem", test_prometheus_metric_no_subsystem},
+#endif
     { 0 }
 };