Added Code coverage support in renode script, makefile target for coverage, GitHub Action for coverage and explaination file

Author: Bharathgopal

…orkflows/disabaled/test-and-coverage.yml …ed/test-and-coverage_with_Bot_Badges.yml.github/workflows/disabaled/test-and-coverage.yml renamed to .github/workflows/disabaled/test-and-coverage_with_Bot_Badges.yml .github/workflows/disabaled/test-and-coverage.yml renamed to .github/workflows/disabaled/test-and-coverage_with_Bot_Badges.yml

@@ -0,0 +1,19 @@
+name: Code Coverage
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  build-test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install dependencies
+        run: sudo apt-get update && sudo apt-get install -y make gcc gcovr build-essential
+      - name: Install Renode
+        run: ./Lab3/install_tools.sh
+      - name: Run renode based code coverage analysis
+        run: make coverage -C Lab3

.github/workflows/test_coverage.yml

@@ -19,11 +19,22 @@ SRC = \
  src/syscalls.c \
  unity/unity.c
 
+.PHONY: all clean run coverage
+
 all:
 	$(CC) $(CFLAGS) $(SRC) $(LDFLAGS) -o $(TARGET).elf
 
 clean:
-	rm -f *.elf
+	rm -f *.elf coverage/trace.*
+
+run: clean all
+	touch coverage/trace.bin
+	renode --disable-xwt renode/stm32.resc
 
-run: all
-	renode --disable-xwt renode/stm32.resc
+coverage: run
+	@python3 /opt/renode/tools/execution_tracer/execution_tracer_reader.py \
+		coverage ./coverage/trace.bin \
+		--binary Lab3.elf \
+		--sources ./src/checksum.c | \
+		awk -F',' '/DA:/ {found++; if($$2>0) hit++} END \
+		{printf "\nTotal Coverage: %.2f%% (%d/%d lines hit)\n", (hit/found)*100, hit, found}'

Lab3/Makefile

@@ -0,0 +1,54 @@
+# How to measure code coverage in renode
+
+* Add these lines after **LoadELF** command in **stm32.resc** file:
+```
+    sysbus.cpu CreateExecutionTracing "tracer" @./coverage/trace.bin PC true
+    sysbus.cpu EnableOpcodesCounting true
+```
+
+* Also add the below line before quit but after execution of test cases to get details of execution 
+```
+    sysbus.cpu GetAllOpcodesCounters
+```
+
+* Run renode execution tracer
+```
+    python3 /opt/renode/tools/execution_tracer/execution_tracer_reader.py \
+		coverage ./coverage/trace.bin \
+		--binary Lab3.elf \
+		--sources ./src/checksum.c
+```
+
+* The above command will generate information of which lines ran and for how many times.
+* Example output:
+```
+    TN:
+    SF:./src/checksum.c
+    DA:5,5
+    DA:6,5
+    DA:7,3
+    DA:10,2
+    DA:11,2
+    DA:13,10
+    DA:15,8
+    DA:17,2
+    DA:18,5
+    end_of_record
+```
+* This is a Address cache which tells which lines ran, how manu times
+```
+    DA:5,2 means line 5 ran 2 times.
+```
+
+* To extract coverage, multiple methods can be tried.
+* Save the above output to a coverage.info 
+1. Run lcov to get % of coverage
+    ```
+        lcov --summary coverage/test.info 
+    ```
+2. Use awk command to extract % of coverage.
+    ```
+        cat coverage/test.info | awk -F',' '/DA:/ {found++; if($2>0) hit++} END {printf "Coverage: %.2f%% (%d/%d)\n", (hit/found)*100, hit, found}'
+    ```
+
+* Both of the above commands give % of coverage of code.

Lab3/coverage/check_coverage.md

@@ -0,0 +1,12 @@
+TN:
+SF:./src/checksum.c
+DA:5,1
+DA:6,1
+DA:7,0
+DA:10,1
+DA:11,1
+DA:13,5
+DA:15,4
+DA:17,1
+DA:18,1
+end_of_record

Lab3/coverage/test.info

@@ -3,8 +3,11 @@ machine LoadPlatformDescription @platforms/boards/stm32f4_discovery-kit.repl
 
 sysbus LoadELF @Lab3.elf
 
+sysbus.cpu CreateExecutionTracing "tracer" @./coverage/trace.bin PC true
+sysbus.cpu EnableOpcodesCounting true
+
 showAnalyzer sysbus.usart2
 
-sysbus.usart2 AddLineHook "TEST_RESULT:" "#print 'completed'";quit
+sysbus.usart2 AddLineHook "TEST_RESULT:" "#print 'completed'";sysbus.cpu GetAllOpcodesCounters;quit
 
 start