Make sure to always log a “Result:” line

Fixes #500.

A side effect of this is that read-only cache misses now will update the
“cache miss” statistics counter, which is consistent with the cache hit
cases (which already now update the counters).

6 files changed, 50 insertions, 26 deletions

diff --git a/doc/MANUAL.adoc b/doc/MANUAL.adoc
index 1717c18e..409d5608 100644
--- a/doc/MANUAL.adoc
+++ b/doc/MANUAL.adoc
@@ -508,9 +508,13 @@ might be incorrect.
 *read_only* (*CCACHE_READONLY* or *CCACHE_NOREADONLY*, see <<_boolean_values,Boolean values>> above)::
 
     If true, ccache will attempt to use existing cached object files, but it
-    will not to try to add anything new to the cache. If you are using this
-    because your ccache directory is read-only, then you need to set
-    *temporary_dir* as otherwise ccache will fail to create temporary files.
+    will not add new results to the cache. Statistics counters will still be
+    updated, though, unless the *stats* option is set to *false*.
++
+If you are using this because your ccache directory is read-only, you need to
+set *temporary_dir* since ccache will fail to create temporary files otherwise.
+You may also want to set *stats = false* to make ccache not even try to update
+stats files.
 
 *read_only_direct* (*CCACHE_READONLY_DIRECT* or *CCACHE_NOREADONLY_DIRECT*, see <<_boolean_values,Boolean values>> above)::
 
diff --git a/src/ccache.c b/src/ccache.c
index 9978d387..e617bf48 100644
--- a/src/ccache.c
+++ b/src/ccache.c
@@ -595,6 +595,7 @@ get_current_working_dir(void)
 		if (!current_working_dir) {
 			cc_log("Unable to determine current working directory: %s",
 			       strerror(errno));
+			stats_update(STATS_ERROR);
 			failed();
 		}
 	}
@@ -1519,18 +1520,21 @@ to_cache(struct args *args, struct hash *depend_mode_hash)
 		if (x_rename(tmp_stderr, tmp_stderr2)) {
 			cc_log("Failed to rename %s to %s: %s", tmp_stderr, tmp_stderr2,
 			       strerror(errno));
+			stats_update(STATS_ERROR);
 			failed();
 		}
 
 		int fd_cpp_stderr = open(cpp_stderr, O_RDONLY | O_BINARY);
 		if (fd_cpp_stderr == -1) {
 			cc_log("Failed opening %s: %s", cpp_stderr, strerror(errno));
+			stats_update(STATS_ERROR);
 			failed();
 		}
 
 		int fd_real_stderr = open(tmp_stderr2, O_RDONLY | O_BINARY);
 		if (fd_real_stderr == -1) {
 			cc_log("Failed opening %s: %s", tmp_stderr2, strerror(errno));
+			stats_update(STATS_ERROR);
 			failed();
 		}
 
@@ -1538,6 +1542,7 @@ to_cache(struct args *args, struct hash *depend_mode_hash)
 			open(tmp_stderr, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666);
 		if (fd_result == -1) {
 			cc_log("Failed opening %s: %s", tmp_stderr, strerror(errno));
+			stats_update(STATS_ERROR);
 			failed();
 		}
 
@@ -1572,6 +1577,7 @@ to_cache(struct args *args, struct hash *depend_mode_hash)
 		struct file_hash *object_hash =
 			object_hash_from_depfile(output_dep, depend_mode_hash);
 		if (!object_hash) {
+			stats_update(STATS_ERROR);
 			failed();
 		}
 		update_cached_result_globals(object_hash);
@@ -1634,7 +1640,7 @@ to_cache(struct args *args, struct hash *depend_mode_hash)
 
 	MTR_END("file", "file_put");
 
-	stats_update(STATS_TOCACHE);
+	stats_update(STATS_CACHEMISS);
 
 	// Make sure we have a CACHEDIR.TAG in the cache part of cache_dir. This can
 	// be done almost anywhere, but we might as well do it near the end as we
@@ -2241,6 +2247,7 @@ calculate_object_hash(struct args *args, struct hash *hash, int direct_mode)
 		hash_delimiter(hash, "sourcecode");
 		int result = hash_source_code_file(conf, hash, input_file);
 		if (result & HASH_SOURCE_CODE_ERROR) {
+			stats_update(STATS_ERROR);
 			failed();
 		}
 		if (result & HASH_SOURCE_CODE_FOUND_TIME) {
@@ -2585,6 +2592,7 @@ cc_process_args(struct args *args,
 			i++;
 			if (i == argc) {
 				cc_log("--ccache-skip lacks an argument");
+				stats_update(STATS_ARGS);
 				result = false;
 				goto out;
 			}
@@ -3091,6 +3099,7 @@ cc_process_args(struct args *args,
 				// know what the user means, and what the compiler will do.
 				if (arg_profile_dir && profile_dir) {
 					cc_log("Profile directory already set; giving up");
+					stats_update(STATS_UNSUPPORTED_OPTION);
 					result = false;
 					goto out;
 				} else if (arg_profile_dir) {
@@ -3885,6 +3894,7 @@ set_up_uncached_err(void)
 	int uncached_fd = dup(2); // The file descriptor is intentionally leaked.
 	if (uncached_fd == -1) {
 		cc_log("dup(2) failed: %s", strerror(errno));
+		stats_update(STATS_ERROR);
 		failed();
 	}
 
@@ -3892,6 +3902,7 @@ set_up_uncached_err(void)
 	char *buf = format("UNCACHED_ERR_FD=%d", uncached_fd);
 	if (putenv(buf) == -1) {
 		cc_log("putenv failed: %s", strerror(errno));
+		stats_update(STATS_ERROR);
 		failed();
 	}
 }
@@ -3935,6 +3946,7 @@ ccache(int argc, char *argv[])
 
 	if (conf->disable) {
 		cc_log("ccache is disabled");
+		stats_update(STATS_CACHEMISS); // Dummy to trigger stats_flush.
 		failed();
 	}
 
@@ -3962,7 +3974,7 @@ ccache(int argc, char *argv[])
 	MTR_BEGIN("main", "process_args");
 	if (!cc_process_args(
 	      orig_args, &preprocessor_args, &extra_args_to_hash, &compiler_args)) {
-		failed();
+		failed(); // stats_update is called in cc_process_args.
 	}
 	MTR_END("main", "process_args");
 
@@ -4050,6 +4062,7 @@ ccache(int argc, char *argv[])
 
 	if (conf->read_only_direct) {
 		cc_log("Read-only direct mode; running real compiler");
+		stats_update(STATS_CACHEMISS);
 		failed();
 	}
 
@@ -4096,6 +4109,7 @@ ccache(int argc, char *argv[])
 
 	if (conf->read_only) {
 		cc_log("Read-only mode; running real compiler");
+		stats_update(STATS_CACHEMISS);
 		failed();
 	}
 
diff --git a/src/ccache.h b/src/ccache.h
index cabc980d..0d6be609 100644
--- a/src/ccache.h
+++ b/src/ccache.h
@@ -1,5 +1,5 @@
 // Copyright (C) 2002-2007 Andrew Tridgell
-// Copyright (C) 2009-2019 Joel Rosdahl
+// Copyright (C) 2009-2020 Joel Rosdahl
 //
 // This program is free software; you can redistribute it and/or modify it
 // under the terms of the GNU General Public License as published by the Free
@@ -43,7 +43,7 @@ enum stats {
 	STATS_STDOUT = 1,
 	STATS_STATUS = 2,
 	STATS_ERROR = 3,
-	STATS_TOCACHE = 4,
+	STATS_CACHEMISS = 4,
 	STATS_PREPROCESSOR = 5,
 	STATS_COMPILER = 6,
 	STATS_MISSING = 7,
diff --git a/src/stats.c b/src/stats.c
index 214f3be5..c06c44b4 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -1,5 +1,5 @@
 // Copyright (C) 2002-2004 Andrew Tridgell
-// Copyright (C) 2009-2019 Joel Rosdahl
+// Copyright (C) 2009-2020 Joel Rosdahl
 //
 // This program is free software; you can redistribute it and/or modify it
 // under the terms of the GNU General Public License as published by the Free
@@ -79,7 +79,7 @@ static struct {
 		FLAG_ALWAYS
 	},
 	{
-		STATS_TOCACHE,
+		STATS_CACHEMISS,
 		"cache_miss",
 		"cache miss",
 		NULL,
@@ -370,7 +370,7 @@ stats_hit_rate(struct counters *counters)
 	unsigned direct = counters->data[STATS_CACHEHIT_DIR];
 	unsigned preprocessed = counters->data[STATS_CACHEHIT_CPP];
 	unsigned hit = direct + preprocessed;
-	unsigned miss = counters->data[STATS_TOCACHE];
+	unsigned miss = counters->data[STATS_CACHEMISS];
 	unsigned total = hit + miss;
 	return total > 0 ? (100.0 * hit) / total : 0.0;
 }
@@ -442,11 +442,26 @@ stats_flush_to_file(const char *sfile, struct counters *updates)
 {
 	assert(conf);
 
-	if (!conf->stats) {
+	if (!updates) {
 		return;
 	}
 
-	if (!updates) {
+	if (conf->disable) {
+		// Just log result, don't update statistics.
+		cc_log("Result: disabled");
+		return;
+	}
+
+	if (!str_eq(conf->log_file, "") || conf->debug) {
+		for (int i = 0; i < STATS_END; ++i) {
+			if (updates->data[stats_info[i].stat] != 0
+			    && !(stats_info[i].flags & FLAG_NOZERO)) {
+				cc_log("Result: %s", stats_info[i].message);
+			}
+		}
+	}
+
+	if (!conf->stats) {
 		return;
 	}
 
@@ -483,15 +498,6 @@ stats_flush_to_file(const char *sfile, struct counters *updates)
 	stats_write(sfile, counters);
 	lockfile_release(sfile);
 
-	if (!str_eq(conf->log_file, "") || conf->debug) {
-		for (int i = 0; i < STATS_END; ++i) {
-			if (updates->data[stats_info[i].stat] != 0
-			    && !(stats_info[i].flags & FLAG_NOZERO)) {
-				cc_log("Result: %s", stats_info[i].message);
-			}
-		}
-	}
-
 	char *subdir = dirname(sfile);
 	bool need_cleanup = false;
 
@@ -591,7 +597,7 @@ stats_summary(void)
 			free(value);
 		}
 
-		if (stat == STATS_TOCACHE) {
+		if (stat == STATS_CACHEMISS) {
 			double percent = stats_hit_rate(counters);
 			printf("cache hit rate                    %6.2f %%\n", percent);
 		}
diff --git a/test/suites/readonly.bash b/test/suites/readonly.bash
index be986966..5cdbc251 100644
--- a/test/suites/readonly.bash
+++ b/test/suites/readonly.bash
@@ -44,9 +44,9 @@ SUITE_readonly() {
     if [ $? -ne 0 ]; then
         test_failed "Failure when compiling test2.c read-only"
     fi
-    if [ -d $CCACHE_DIR ]; then
-        test_failed "ccache dir was created"
-    fi
+    expect_stat 'cache hit (preprocessed)' 0
+    expect_stat 'cache miss' 1
+    expect_stat 'files in cache' 0
 
     # -------------------------------------------------------------------------
     # Check that read-only mode and direct mode work together.
diff --git a/test/suites/readonly_direct.bash b/test/suites/readonly_direct.bash
index b1ea4c6e..9a7636f4 100644
--- a/test/suites/readonly_direct.bash
+++ b/test/suites/readonly_direct.bash
@@ -29,5 +29,5 @@ SUITE_readonly_direct() {
     CCACHE_READONLY_DIRECT=1 $CCACHE_COMPILE -DFOO -c test.c -o test.o
     expect_stat 'cache hit (direct)' 0
     expect_stat 'cache hit (preprocessed)' 0
-    expect_stat 'cache miss' 1
+    expect_stat 'cache miss' 2
 }