$(TARGET_CFLAGS) causes build to fail for ramips

[cpswan]

Describe the bug

#26 introduced the $(TARGET_CFLAGS) to -DMAKE_C_FLAGS to prevent numerous someone does not honour COPTS correctly warnings during builds.

This has broken building for ramips targets (e.g. GL.iNet MT1300):

[  6%] Building C object _deps/mbedtls-build/library/CMakeFiles/mbedcrypto.dir/bignum_core.c.o
{standard input}: Assembler messages:
{standard input}:1110: Error: invalid operands `lw $10,16($sp)'
.
<snip>
.
{standard input}:1261: Error: invalid operands `sw $10,16($sp)'

Steps to reproduce

1. First I install the GL.Inet SDK and download the ramips platform (or an equivalent OpenWrt SDK)
2. Then I follow the steps in fix: Working Makefile for csshnpd on MIPS #14 to configure feeds and update CMake
3. And then I make V=s package/csshnpd/compile

Expected behavior

The build should complete without compiler errors.

👀 @XavierChanth @JeremyTubongbanua so that you're aware, though I'm seeing this as an OpenWrt thing rather than C sshnpd or at_c

Additional context

The build logs show this being passed for C_FLAGS:

CFLAGS="-Os -pipe -mno-branch-likely -mips32r2 -mtune=24kc -fno-caller-saves -fno-plt -fhonour-copts -Wno-error=unused-but-set-variable -Wno-error=unused-result -msoft-float -mips16 -minterlink-mips16 -iremap/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/build_dir/target-mipsel_24kc_musl/csshnpd-c0.2.4:csshnpd-c0.2.4 -Wformat -Werror=format-security -fstack-protector -D_FORTIFY_SOURCE=1 -Wl,-z,now -Wl,-z,relro  -I/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/staging_dir/target-mipsel_24kc_musl/usr/include -I/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/staging_dir/target-mipsel_24kc_musl/include -I/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/staging_dir/toolchain-mipsel_24kc_gcc-7.5.0_musl/usr/include -I/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/staging_dir/toolchain-mipsel_24kc_gcc-7.5.0_musl/include/fortify -I/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/staging_dir/toolchain-mipsel_24kc_gcc-7.5.0_musl/include "

I strongly suspect that mips16 is the problem here, and it probably should not be passed along with -mips32r2 -mtune=24kc

If I pass -fhonour-copts in place of $(TARGET_CFLAGS) then it's possible to get a good build with no warnings.

Full log from failed build step:

[  6%] Building C object _deps/mbedtls-build/library/CMakeFiles/mbedcrypto.dir/bignum_core.c.o
{standard input}: Assembler messages:
{standard input}:1110: Error: invalid operands `lw $10,16($sp)'
{standard input}:1111: Error: invalid operands `lw $11,8($sp)'
{standard input}:1112: Error: invalid operands `lw $12,4($sp)'
{standard input}:1113: Error: invalid operands `lw $13,24($sp)'
{standard input}:1114: Error: invalid operands `lw $14,0($10)'
{standard input}:1115: Error: invalid operands `multu $13,$14'
{standard input}:1116: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1117: Error: invalid operands `mflo $14'
{standard input}:1118: Error: invalid operands `mfhi $9'
{standard input}:1119: Error: invalid operands `addu $14,$12,$14'
{standard input}:1120: Error: invalid operands `lw $15,0($11)'
{standard input}:1121: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1122: Error: invalid operands `addu $15,$14,$15'
{standard input}:1123: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1124: Error: invalid operands `addu $12,$12,$9'
{standard input}:1125: Error: invalid operands `sw $15,0($11)'
{standard input}:1126: Error: invalid operands `addu $12,$12,$14'
{standard input}:1127: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1128: Error: invalid operands `lw $14,0($10)'
{standard input}:1129: Error: invalid operands `multu $13,$14'
{standard input}:1130: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1131: Error: invalid operands `mflo $14'
{standard input}:1132: Error: invalid operands `mfhi $9'
{standard input}:1133: Error: invalid operands `addu $14,$12,$14'
{standard input}:1134: Error: invalid operands `lw $15,0($11)'
{standard input}:1135: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1136: Error: invalid operands `addu $15,$14,$15'
{standard input}:1137: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1138: Error: invalid operands `addu $12,$12,$9'
{standard input}:1139: Error: invalid operands `sw $15,0($11)'
{standard input}:1140: Error: invalid operands `addu $12,$12,$14'
{standard input}:1141: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1142: Error: invalid operands `lw $14,0($10)'
{standard input}:1143: Error: invalid operands `multu $13,$14'
{standard input}:1144: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1145: Error: invalid operands `mflo $14'
{standard input}:1146: Error: invalid operands `mfhi $9'
{standard input}:1147: Error: invalid operands `addu $14,$12,$14'
{standard input}:1148: Error: invalid operands `lw $15,0($11)'
{standard input}:1149: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1150: Error: invalid operands `addu $15,$14,$15'
{standard input}:1151: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1152: Error: invalid operands `addu $12,$12,$9'
{standard input}:1153: Error: invalid operands `sw $15,0($11)'
{standard input}:1154: Error: invalid operands `addu $12,$12,$14'
{standard input}:1155: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1156: Error: invalid operands `lw $14,0($10)'
{standard input}:1157: Error: invalid operands `multu $13,$14'
{standard input}:1158: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1159: Error: invalid operands `mflo $14'
{standard input}:1160: Error: invalid operands `mfhi $9'
{standard input}:1161: Error: invalid operands `addu $14,$12,$14'
{standard input}:1162: Error: invalid operands `lw $15,0($11)'
{standard input}:1163: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1164: Error: invalid operands `addu $15,$14,$15'
{standard input}:1165: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1166: Error: invalid operands `addu $12,$12,$9'
{standard input}:1167: Error: invalid operands `sw $15,0($11)'
{standard input}:1168: Error: invalid operands `addu $12,$12,$14'
{standard input}:1169: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1170: Error: invalid operands `lw $14,0($10)'
{standard input}:1171: Error: invalid operands `multu $13,$14'
{standard input}:1172: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1173: Error: invalid operands `mflo $14'
{standard input}:1174: Error: invalid operands `mfhi $9'
{standard input}:1175: Error: invalid operands `addu $14,$12,$14'
{standard input}:1176: Error: invalid operands `lw $15,0($11)'
{standard input}:1177: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1178: Error: invalid operands `addu $15,$14,$15'
{standard input}:1179: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1180: Error: invalid operands `addu $12,$12,$9'
{standard input}:1181: Error: invalid operands `sw $15,0($11)'
{standard input}:1182: Error: invalid operands `addu $12,$12,$14'
{standard input}:1183: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1184: Error: invalid operands `lw $14,0($10)'
{standard input}:1185: Error: invalid operands `multu $13,$14'
{standard input}:1186: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1187: Error: invalid operands `mflo $14'
{standard input}:1188: Error: invalid operands `mfhi $9'
{standard input}:1189: Error: invalid operands `addu $14,$12,$14'
{standard input}:1190: Error: invalid operands `lw $15,0($11)'
{standard input}:1191: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1192: Error: invalid operands `addu $15,$14,$15'
{standard input}:1193: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1194: Error: invalid operands `addu $12,$12,$9'
{standard input}:1195: Error: invalid operands `sw $15,0($11)'
{standard input}:1196: Error: invalid operands `addu $12,$12,$14'
{standard input}:1197: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1198: Error: invalid operands `lw $14,0($10)'
{standard input}:1199: Error: invalid operands `multu $13,$14'
{standard input}:1200: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1201: Error: invalid operands `mflo $14'
{standard input}:1202: Error: invalid operands `mfhi $9'
{standard input}:1203: Error: invalid operands `addu $14,$12,$14'
{standard input}:1204: Error: invalid operands `lw $15,0($11)'
{standard input}:1205: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1206: Error: invalid operands `addu $15,$14,$15'
{standard input}:1207: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1208: Error: invalid operands `addu $12,$12,$9'
{standard input}:1209: Error: invalid operands `sw $15,0($11)'
{standard input}:1210: Error: invalid operands `addu $12,$12,$14'
{standard input}:1211: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1212: Error: invalid operands `lw $14,0($10)'
{standard input}:1213: Error: invalid operands `multu $13,$14'
{standard input}:1214: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1215: Error: invalid operands `mflo $14'
{standard input}:1216: Error: invalid operands `mfhi $9'
{standard input}:1217: Error: invalid operands `addu $14,$12,$14'
{standard input}:1218: Error: invalid operands `lw $15,0($11)'
{standard input}:1219: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1220: Error: invalid operands `addu $15,$14,$15'
{standard input}:1221: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1222: Error: invalid operands `addu $12,$12,$9'
{standard input}:1223: Error: invalid operands `sw $15,0($11)'
{standard input}:1224: Error: invalid operands `addu $12,$12,$14'
{standard input}:1225: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1226: Error: invalid operands `sw $12,4($sp)'
{standard input}:1227: Error: invalid operands `sw $11,8($sp)'
{standard input}:1228: Error: invalid operands `sw $10,16($sp)'
{standard input}:1241: Error: invalid operands `lw $10,16($sp)'
{standard input}:1242: Error: invalid operands `lw $11,8($sp)'
{standard input}:1243: Error: invalid operands `lw $12,4($sp)'
{standard input}:1244: Error: invalid operands `lw $13,24($sp)'
{standard input}:1245: Error: invalid operands `lw $14,0($10)'
{standard input}:1246: Error: invalid operands `multu $13,$14'
{standard input}:1247: Error: unrecognized opcode `addi $10,$10,4'
{standard input}:1248: Error: invalid operands `mflo $14'
{standard input}:1249: Error: invalid operands `mfhi $9'
{standard input}:1250: Error: invalid operands `addu $14,$12,$14'
{standard input}:1251: Error: invalid operands `lw $15,0($11)'
{standard input}:1252: Error: invalid operands `sltu $12,$14,$12'
{standard input}:1253: Error: invalid operands `addu $15,$14,$15'
{standard input}:1254: Error: invalid operands `sltu $14,$15,$14'
{standard input}:1255: Error: invalid operands `addu $12,$12,$9'
{standard input}:1256: Error: invalid operands `sw $15,0($11)'
{standard input}:1257: Error: invalid operands `addu $12,$12,$14'
{standard input}:1258: Error: unrecognized opcode `addi $11,$11,4'
{standard input}:1259: Error: invalid operands `sw $12,4($sp)'
{standard input}:1260: Error: invalid operands `sw $11,8($sp)'
{standard input}:1261: Error: invalid operands `sw $10,16($sp)'
make[5]: *** [_deps/mbedtls-build/library/CMakeFiles/mbedcrypto.dir/build.make:188: _deps/mbedtls-build/library/CMakeFiles/mbedcrypto.dir/bignum_core.c.o] Error 1
make[5]: Leaving directory '/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/build_dir/target-mipsel_24kc_musl/csshnpd-c0.2.4'
make[4]: *** [CMakeFiles/Makefile2:1019: _deps/mbedtls-build/library/CMakeFiles/mbedcrypto.dir/all] Error 2
make[4]: Leaving directory '/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/build_dir/target-mipsel_24kc_musl/csshnpd-c0.2.4'
make[3]: *** [Makefile:136: all] Error 2
make[3]: Leaving directory '/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/build_dir/target-mipsel_24kc_musl/csshnpd-c0.2.4'
make[2]: *** [Makefile:56: /home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/build_dir/target-mipsel_24kc_musl/csshnpd-c0.2.4/.built] Error 2
make[2]: Leaving directory '/home/chris/git/github.com/atsign-foundation/Atsign_OpenWRT_packages/packages/csshnpd'
time: package/feeds/atsign/csshnpd/compile#10.06#4.58#16.73
make[1]: *** [package/Makefile:113: package/feeds/atsign/csshnpd/compile] Error 2
make[1]: Leaving directory '/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips'
make: *** [/home/chris/git/github.com/gl-inet/sdk/sdk/1907/ramips/include/toplevel.mk:220: package/csshnpd/compile] Error 2