Use CBMC XML output to enable VSCode debugger (#912)

Prior to this commit, CBMC would emit logging information in plain text
format, which does not contain information required for the CBMC VSCode
debugger. This commit makes CBMC use XML instead of plain text.

Co-authored-by: Mark Tuttle <tuttle@acm.org>

FreeRTOS/Test/CBMC/proofs/Makefile.template

@@ -119,8 +119,8 @@ goto:
 # Ignore the return code for CBMC, so that we can still generate the
 # report if the proof failed. If the proof failed, we separately fail
 # the entire job using the check-cbmc-result rule.
-cbmc.txt: $(ENTRY).goto
-	-cbmc $(CBMCFLAGS) $(SOLVER) --unwinding-assertions --trace @RULE_INPUT@ > $@ 2>&1
+cbmc.xml: $(ENTRY).goto
+	-cbmc $(CBMCFLAGS) $(SOLVER) --unwinding-assertions --trace --xml-ui @RULE_INPUT@ > $@ 2>&1
 
 property.xml: $(ENTRY).goto
 	cbmc $(CBMCFLAGS) --unwinding-assertions --show-properties --xml-ui @RULE_INPUT@ > $@ 2>&1
@@ -128,28 +128,27 @@ property.xml: $(ENTRY).goto
 coverage.xml: $(ENTRY).goto
 	cbmc $(CBMCFLAGS) --cover location --xml-ui @RULE_INPUT@ > $@ 2>&1
 
-cbmc: cbmc.txt
+cbmc: cbmc.xml
 
 property: property.xml
 
 coverage: coverage.xml
 
-report: cbmc.txt property.xml coverage.xml
+report: cbmc.xml property.xml coverage.xml
 	$(VIEWER) \
 	--goto $(ENTRY).goto \
 	--srcdir $(FREERTOS) \
-	--htmldir html \
-	--srcexclude "(.@FORWARD_SLASH@Demo)" \
-	--result cbmc.txt \
+	--reportdir html \
+	--result cbmc.xml \
 	--property property.xml \
-	--block coverage.xml
+	--coverage coverage.xml
 
-# This rule depends only on cbmc.txt and has no dependents, so it will
+# This rule depends only on cbmc.xml and has no dependents, so it will
 # not block the report from being generated if it fails. This rule is
 # intended to fail if and only if the CBMC safety check that emits
-# cbmc.txt yielded a proof failure.
-check-cbmc-result: cbmc.txt
-	grep -e "^VERIFICATION SUCCESSFUL" $^
+# cbmc.xml yielded a proof failure.
+check-cbmc-result: cbmc.xml
+	grep -e "<cprover-status>SUCCESS</cprover-status>" $^
 
 # ____________________________________________________________________
 # Rules
@@ -159,7 +158,7 @@ check-cbmc-result: cbmc.txt
 clean:
 	@RM@ $(OBJS) $(ENTRY).goto
 	@RM@ $(ENTRY)[0-9].goto $(ENTRY)[0-9].txt
-	@RM@ cbmc.txt property.xml coverage.xml TAGS TAGS-*
+	@RM@ cbmc.xml property.xml coverage.xml TAGS TAGS-*
 	@RM@ *~ \#*
 	@RM@ queue_datastructure.h