Add Python script to check function namespacing

Makefile

@@ -42,6 +42,16 @@ bin/testvectors_$(subst /,_,$(SCHEME)): test/$(dir $(SCHEME))testvectors.c $(wil
 .PHONY: testvectors
 testvectors: bin/testvectors_$(subst /,_,$(SCHEME))
 
+bin/shared_$(subst /,_,$(SCHEME))_clean.so: $(wildcard $(SCHEME)/clean/*.c) | require_scheme
+	mkdir -p bin
+	gcc $(CFLAGS) \
+		-shared \
+		-fPIC \
+		-iquote "./common/" \
+		-iquote "$(SCHEME)/clean/" \
+		-o $@ \
+		$^
+
 .PHONY: clean
 clean:
 	rm -rf bin

test/check_symbol_namespace.py

@@ -0,0 +1,37 @@
+import subprocess
+import sys
+
+"""
+For a given SCHEME, this script verifies that all exported symbols are properly
+namespaced, i.e., all start with "PQCLEAN_SCHEMENAME_"
+"""
+
+if len(sys.argv) != 2:
+    print("Provide a scheme name (e.g. crypto_kem/kyber768) as argv[1]")
+    exit(1)
+
+SCHEME = sys.argv[1]
+SCHEMEFULL = SCHEME.replace('/', '_')  # e.g. crypto_kem_kyber768
+SCHEMESHORT = SCHEME.split('/')[1].upper()
+namespace = f"PQCLEAN_{SCHEMESHORT}_"
+
+# TODO can we do this using object files instead, to preserve file origin?
+sharedlib = f"bin/shared_{SCHEMEFULL}_clean.so"
+subprocess.run(["make", sharedlib, f"SCHEME={SCHEME}"])
+p = subprocess.run(["nm", "-D", sharedlib], capture_output=True)
+
+symbols = p.stdout.decode('utf-8').strip().split("\n")
+non_namespaced = []
+
+for symbolstr in symbols:
+    *_, symtype, symbol = symbolstr.split()
+    if symtype in 'TR':
+        if not symbol.startswith(namespace):
+            non_namespaced.append(symbol)
+
+if non_namespaced:
+    print("! Not all symbols were properly namespaced.", file=sys.stderr)
+    print(f"! Missing namespace literal {namespace}", file=sys.stderr)
+    for symbol in non_namespaced:
+        print(f"\t{symbol}", file=sys.stderr)
+    sys.exit(1)