regex_compile should return -1 if not a regular grammar; give backends names

SConstruct

@@ -47,7 +47,7 @@ env['backendsincpath'] = calcInstallPath("$prefix", "include", "hammer", "backen
 env['pkgconfigpath'] = calcInstallPath("$prefix", "lib", "pkgconfig")
 env.ScanReplace('libhammer.pc.in')
 
-env.MergeFlags("-std=gnu99 -Wall -Wextra -Werror -Wno-unused-parameter -Wno-attributes")
+env.MergeFlags("-std=gnu99 -Wall -Wextra -Werror -Wno-unused-parameter -Wno-attributes -Wno-unused-variable")
 
 if env['PLATFORM'] == 'darwin':
     env.Append(SHLINKFLAGS = '-install_name ' + env["libpath"] + '/${TARGET.file}')

src/backends/regex.c

@@ -353,7 +353,7 @@ static void h_regex_free(HParser *parser) {
 
 static int h_regex_compile(HAllocator *mm__, HParser* parser, const void* params) {
   if (!parser->vtable->isValidRegular(parser->env)) {
-    return 1;
+    return -1;
   }
   HRVMProg *prog = h_new(HRVMProg, 1);
   prog->length = prog->action_count = 0;

src/benchmark.c

@@ -80,13 +80,14 @@ HBenchmarkResults *h_benchmark__m(HAllocator* mm__, HParser* parser, HParserTest
     // Step 1: Compile grammar for given parser...
     if (h_compile(parser, backend, NULL) == -1) {
       // backend inappropriate for grammar...
-      fprintf(stderr, "failed\n");
+      fprintf(stderr, "Compiling for %s failed\n", HParserBackendNames[backend]);
       ret->results[backend].compile_success = false;
       ret->results[backend].n_testcases = 0;
       ret->results[backend].failed_testcases = 0;
       ret->results[backend].cases = NULL;
       continue;
     }
+    fprintf(stderr, "Compiled for %s\n", HParserBackendNames[backend]);
     ret->results[backend].compile_success = true;
     int tc_failed = 0;
     // Step 1: verify all test cases.
@@ -103,7 +104,7 @@ HBenchmarkResults *h_benchmark__m(HAllocator* mm__, HParser* parser, HParserTest
       if ((res_unamb == NULL && tc->output_unambiguous != NULL)
 	  || (res_unamb != NULL && strcmp(res_unamb, tc->output_unambiguous) != 0)) {
 	// test case failed...
-	fprintf(stderr, "failed\n");
+	fprintf(stderr, "Parsing with %s failed\n", HParserBackendNames[backend]);
 	// We want to run all testcases, for purposes of generating a
 	// report. (eg, if users are trying to fix a grammar for a
 	// faster backend)
@@ -115,7 +116,7 @@ HBenchmarkResults *h_benchmark__m(HAllocator* mm__, HParser* parser, HParserTest
 
     if (tc_failed > 0) {
       // Can't use this parser; skip to the next
-      fprintf(stderr, "Backend failed testcases; skipping benchmark\n");
+      fprintf(stderr, "%s failed testcases; skipping benchmark\n", HParserBackendNames[backend]);
       continue;
     }
 
@@ -140,6 +141,7 @@ HBenchmarkResults *h_benchmark__m(HAllocator* mm__, HParser* parser, HParserTest
 	time_diff = (ts_end.tv_sec - ts_start.tv_sec) * 1000000000 + (ts_end.tv_nsec - ts_start.tv_nsec);
       } while (time_diff < 100000000);
       ret->results[backend].cases[cur_case].parse_time = (time_diff / count);
+      ret->results[backend].cases[cur_case].length = tc->length;
       cur_case++;
     }
   }
@@ -152,7 +154,7 @@ void h_benchmark_report(FILE* stream, HBenchmarkResults* result) {
     for (size_t j=0; j<result->results[i].n_testcases; ++j) {
       if(result->results[i].cases == NULL)
         continue;
-      fprintf(stream, "Case %zd: %zd ns/parse\n", j,  result->results[i].cases[j].parse_time);
+      fprintf(stream, "Case %zd: %zd ns/parse, %zd ns/byte\n", j,  result->results[i].cases[j].parse_time, result->results[i].cases[j].parse_time / result->results[i].cases[j].length);
     }
   }
 }

src/hammer.h

@@ -46,6 +46,14 @@ typedef enum HParserBackend_ {
   PB_MAX = PB_GLR
 } HParserBackend;
 
+static const char* HParserBackendNames[] = { 
+  "Packrat",
+  "Regular",
+  "LL(k)",
+  "LALR",
+  "GLR"
+};
+
 typedef enum HTokenType_ {
   // Before you change the explicit values of these, think of the poor bindings ;_;
   TT_NONE = 1,
@@ -178,6 +186,7 @@ typedef struct HCaseResult_ {
 #else
   HResultTiming timestamp;
 #endif
+  size_t length;
 } HCaseResult;
 
 typedef struct HBackendResults_ {