ESP: get march and mabi flags from sdk (apple#72)

Refactors CMake configuration to automatically extract `-march` and
`-mabi` flags from existing CMake variables set by ESP-IDF.

This change makes it easier to add new Espressif RISC-V targets.

esp32-led-blink-sdk/main/CMakeLists.txt

@@ -11,15 +11,14 @@ if("${arch}" STREQUAL "xtensa")
     message(FATAL_ERROR "Not supported target: ${target}")
 endif()
 
-if(${target} STREQUAL "esp32c2" OR ${target} STREQUAL "esp32c3")
-    set(march_flag "rv32imc_zicsr_zifencei")
-    set(mabi_flag "ilp32")
-elseif(${target} STREQUAL "esp32p4")
-    set(march_flag "rv32imafc_zicsr_zifencei")
-    set(mabi_flag "ilp32f")
-else()
-    set(march_flag "rv32imac_zicsr_zifencei")
-    set(mabi_flag "ilp32")
+# Extract the -march flag and remove any vendor-specific extensions (_x*)
+string(REGEX MATCH "-march=[^ ]+" march_flag "${CMAKE_C_FLAGS}")
+string(REGEX REPLACE "_x[^ ]*" "" march_flag "${march_flag}")
+
+# Extract the -mabi flag or set a default value if not present
+string(REGEX MATCH "-mabi=[^ ]+" mabi_flag "${CMAKE_C_FLAGS}")
+if("${mabi_flag}" STREQUAL "")
+    set(mabi_flag "-mabi=ilp32")
 endif()
 
 # Clear the default COMPILE_OPTIONS which include a lot of C/C++ specific compiler flags that the Swift compiler will not accept
@@ -41,7 +40,7 @@ endforeach()
 target_compile_options(${COMPONENT_LIB} PUBLIC "$<$<COMPILE_LANGUAGE:Swift>:SHELL:
         -target riscv32-none-none-eabi
         -Xfrontend -function-sections -enable-experimental-feature Embedded -wmo -parse-as-library -Osize
-        -Xcc -march=${march_flag} -Xcc -mabi=${mabi_flag} -Xcc -fno-pic -Xcc -fno-pie
+        -Xcc ${march_flag} -Xcc ${mabi_flag} -Xcc -fno-pic -Xcc -fno-pie
         
         -pch-output-dir /tmp
         -Xfrontend -enable-single-module-llvm-emission

esp32-led-strip-sdk/main/CMakeLists.txt

@@ -11,15 +11,14 @@ if("${arch}" STREQUAL "xtensa")
     message(FATAL_ERROR "Not supported target: ${target}")
 endif()
 
-if(${target} STREQUAL "esp32c2" OR ${target} STREQUAL "esp32c3")
-    set(march_flag "rv32imc_zicsr_zifencei")
-    set(mabi_flag "ilp32")
-elseif(${target} STREQUAL "esp32p4")
-    set(march_flag "rv32imafc_zicsr_zifencei")
-    set(mabi_flag "ilp32f")
-else()
-    set(march_flag "rv32imac_zicsr_zifencei")
-    set(mabi_flag "ilp32")
+# Extract the -march flag and remove any vendor-specific extensions (_x*)
+string(REGEX MATCH "-march=[^ ]+" march_flag "${CMAKE_C_FLAGS}")
+string(REGEX REPLACE "_x[^ ]*" "" march_flag "${march_flag}")
+
+# Extract the -mabi flag or set a default value if not present
+string(REGEX MATCH "-mabi=[^ ]+" mabi_flag "${CMAKE_C_FLAGS}")
+if("${mabi_flag}" STREQUAL "")
+    set(mabi_flag "-mabi=ilp32")
 endif()
 
 # Clear the default COMPILE_OPTIONS which include a lot of C/C++ specific compiler flags that the Swift compiler will not accept
@@ -41,7 +40,7 @@ endforeach()
 target_compile_options(${COMPONENT_LIB} PUBLIC "$<$<COMPILE_LANGUAGE:Swift>:SHELL:
         -target riscv32-none-none-eabi
         -Xfrontend -function-sections -enable-experimental-feature Embedded -wmo -parse-as-library -Osize
-        -Xcc -march=${march_flag} -Xcc -mabi=${mabi_flag} -Xcc -fno-pic -Xcc -fno-pie
+        -Xcc ${march_flag} -Xcc ${mabi_flag} -Xcc -fno-pic -Xcc -fno-pie
         
         -pch-output-dir /tmp
         -Xfrontend -enable-single-module-llvm-emission