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

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>
falcosecurity · Sep 11, 2024 · 4bc456d · 4bc456d
1 parent 215db2d
commit 4bc456d
Show file tree

Hide file tree

Showing 2 changed files with 34 additions and 4 deletions.
diff --git a/cmake/modules/grpc.cmake b/cmake/modules/grpc.cmake
@@ -174,6 +174,19 @@ 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 +236,7 @@ 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 +25,31 @@ 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})