Make the CI actually work (facebook#1)

Summary:
Pull Request resolved: facebook#1

- add CI badge to the README
- do not hardcode the compiler and the compiler flags
- fix link flags

Reviewed By: kernelslacker

Differential Revision: D31489684

fbshipit-source-id: c0c983545bcb102d22e8d091126f526bca77c239

.github/workflows/ci.yml

@@ -5,7 +5,18 @@ on:
   pull_request:
 jobs:
   build:
+    name: Build netconsd
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - cc: gcc
+            cxx: g++
+          - cc: clang
+            cxx: clang++
+    env:
+      CC: ${{ matrix.cc }}
+      CXX: ${{ matrix.cxx }}
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2

Makefile

@@ -1,8 +1,10 @@
-CC = gcc
+CC ?= gcc
 
-export LDFLAGS = -lpthread -lrt -ldl
-export CFLAGS = -O2 -D_GNU_SOURCE -fno-strict-aliasing -Wall -Wextra \
-	-Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations \
+LDFLAGS ?= -shared
+LIBS = -lpthread -lrt -ldl
+CFLAGS ?= -O2 -fPIC
+CFLAGS += -D_GNU_SOURCE -fno-strict-aliasing -Wall -Wextra \
+  	-Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations \
 	-Wdeclaration-after-statement -Wno-missing-field-initializers \
 	-Wno-unused-parameter
 INCLUDES = -Incrx
@@ -31,7 +33,7 @@ disasm: $(asm)
 -include $(obj:.o=.d)
 
 $(binary): $(lib) $(obj)
-	$(CC) $(LDFLAGS) $(lib) $(obj) -o $@
+	$(CC) $(LDFLAGS) $(LIBS) $(lib) $(obj) -o $@
 
 %.o: %.c
 	$(CC) $< $(CFLAGS) $(INCLUDES) -c -o $@

README.md

@@ -1,5 +1,7 @@
 # Netconsd: The Netconsole Daemon
 
+[![Continuous Integration](https://github.com/facebook/netconsd/workflows/Continuous%20Integration/badge.svg?event=push)](https://github.com/facebook/netconsd/actions?query=workflow%3A%22Continuous+Integration%22)
+
 This is a daemon for receiving and processing logs from the Linux Kernel, as
 emitted over a network by the kernel's netconsole module. It supports both the
 old "legacy" text-only format, and the new extended format added in v4.4.

modules/Makefile

@@ -1,5 +1,6 @@
-CC = gcc
-CCC = g++
+CC ?= gcc
+CXX ?= g++
+LDFLAGS ?= -shared -static-libstdc++ -static-libgcc
 
 override CFLAGS += -fPIC
 INCLUDES = -I../ncrx -I../include
@@ -14,11 +15,11 @@ all: $(mods)
 
 %.so: %.c
 	$(CC) $< $(CFLAGS) $(INCLUDES) $(LDFLAGS) -c -o $(<:.c=.o)
-	$(CC) $(<:.c=.o) $(LDFLAGS) -shared -o $@
+	$(CC) $(<:.c=.o) $(LDFLAGS) -o $@
 
 %.so: %.cc
-	$(CCC) $< $(CCFLAGS) $(INCLUDES) $(LDFLAGS) -c -o $(<:.cc=.o)
-	$(CCC) $(<:.cc=.o) $(LDFLAGS) -shared -static-libstdc++ -static-libgcc \
+	$(CXX) $< $(CCFLAGS) $(INCLUDES) $(LDFLAGS) -c -o $(<:.cc=.o)
+	$(CXX) $(<:.cc=.o) $(LDFLAGS) \
 			-o $@
 
 clean:

ncrx/Makefile

@@ -1,6 +1,7 @@
-CC = gcc
+CC ?= gcc
 
-CFLAGS = -O2 -D_GNU_SOURCE -fno-strict-aliasing -Wall -Wextra \
+CFLAGS ?= -O2 -fPIC
+CFLAGS += -D_GNU_SOURCE -fno-strict-aliasing -Wall -Wextra \
 	-Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations \
 	-Wdeclaration-after-statement -Wno-missing-field-initializers \
 	-Wno-unused-function -Wno-unused-parameter

util/Makefile

@@ -1,7 +1,9 @@
-CFLAGS = -D_GNU_SOURCE
-LDFLAGS = -lpthread
+CFLAGS ?= -O2 -fPIC
+CFLAGS += -D_GNU_SOURCE
+LDFLAGS ?= -shared
+LIBS = -lpthread
 
 all: netconsblaster
 
 netconsblaster:
-	$(CC) $(LDFLAGS) $(CFLAGS) netconsblaster.c -o netconsblaster
+	$(CC) $(LDFLAGS) $(CFLAGS) netconsblaster.c $(LIBS) -o netconsblaster