fix(cmake): add zig workarounds for libelf and grpc cmake modules.

Signed-off-by: Federico Di Pierro <[email protected]>
falcosecurity · Sep 11, 2024 · e63d212 · e63d212
1 parent 215db2d
commit e63d212
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Showing 2 changed files with 30 additions and 4 deletions.
diff --git a/cmake/modules/grpc.cmake b/cmake/modules/grpc.cmake
@@ -174,6 +174,17 @@ else()
 			"${GRPC_SRC}/third_party/abseil-cpp/absl/random/libabsl_random_seed_gen_exception.a"
 		)
 
+		set(GRPC_PATCH_CMD "")
+		# Zig workaround:
+		# Add a PATCH_COMMAND to grpc cmake
+		## to fixup emitted -march by abseil-cpp cmake module,
+		## making it use a name understood by zig for arm64.
+		## See https://github.com/abseil/abseil-cpp/blob/master/absl/copts/GENERATED_AbseilCopts.cmake#L226.
+		if (CMAKE_C_COMPILER MATCHES "zig")
+			message(STATUS "Enabling zig workaround for abseil-cpp")
+			set(GRPC_PATCH_CMD sh -c "sed -i 's/armv8-a/cortex_a57/g' ${GRPC_SRC}/third_party/abseil-cpp/absl/copts/GENERATED_AbseilCopts.cmake")
+		endif()
+
 		ExternalProject_Add(
 			grpc
 			PREFIX "${PROJECT_BINARY_DIR}/grpc-prefix"
@@ -223,6 +234,7 @@ else()
 			# Keep installation files into the local ${GRPC_INSTALL_DIR} since here is the case when
 			# we are embedding gRPC
 			UPDATE_COMMAND ""
+			PATCH_COMMAND ${GRPC_PATCH_CMD}
 			INSTALL_COMMAND DESTDIR= ${CMAKE_MAKE_PROGRAM} install
 		)
 		install(

diff --git a/cmake/modules/libelf.cmake b/cmake/modules/libelf.cmake
@@ -25,15 +25,29 @@ elseif(NOT USE_BUNDLED_LIBELF)
 	else()
 		set(LIBELF_LIB_SUFFIX ${CMAKE_STATIC_LIBRARY_SUFFIX})
 	endif()
-	find_library(LIBELF_LIB NAMES libelf${LIBELF_LIB_SUFFIX})
+	# Zig workaround:
+	# since it won't look up in /usr/lib/..., add an HINT
+	if (CMAKE_C_COMPILER MATCHES "zig")
+		find_library(LIBELF_LIB NAMES libelf${LIBELF_LIB_SUFFIX} HINTS /usr/lib/${CMAKE_SYSTEM_PROCESSOR}-linux-gnu/)
+	else()
+		find_library(LIBELF_LIB NAMES libelf${LIBELF_LIB_SUFFIX})
+	endif()
 	if(LIBELF_LIB)
+		# Zig workaround:
+		# avoid include whole /usr/include because it would
+		# include also system glibc headers breaking the build since
+		# we are targeting the build against our boostrapped zig.
+		if (CMAKE_C_COMPILER MATCHES "zig")
+			message(STATUS "Enabling zig workaround for libelf")
+			configure_file(${LIBELF_INCLUDE}/libelf.h libelf/libelf.h COPYONLY)
+			configure_file(${LIBELF_INCLUDE}/elf.h libelf/elf.h COPYONLY)
+			configure_file(${LIBELF_INCLUDE}/gelf.h libelf/gelf.h COPYONLY)
+			set(LIBELF_INCLUDE ${CMAKE_CURRENT_BINARY_DIR}/libelf)
+		endif()
 		message(STATUS "Found LIBELF: include: ${LIBELF_INCLUDE}, lib: ${LIBELF_LIB}")
 	else()
 		message(FATAL_ERROR "Couldn't find system libelf")
 	endif()
-	# We add a custom target, in this way we can always depend on `libelf` without distinguishing
-	# between "bundled" and "not-bundled" case
-	add_custom_target(libelf)
 else()
 	if(BUILD_SHARED_LIBS)
 		set(LIBELF_LIB_SUFFIX ${CMAKE_SHARED_LIBRARY_SUFFIX})