[C++] Add --warn flag which produces extra warnings

4 files changed, 12 insertions, 0 deletions

diff --git a/flags.cc b/flags.cc
index daf0c19..06772f0 100644
--- a/flags.cc
+++ b/flags.cc
@@ -67,6 +67,8 @@ void Flags::Parse(int argc, char** argv) {
       is_silent_mode = true;
     } else if (!strcmp(arg, "--kati_stats")) {
       enable_stat_logs = true;
+    } else if (!strcmp(arg, "--warn")) {
+      enable_kati_warnings = true;
     } else if (!strcmp(arg, "--ninja")) {
       generate_ninja = true;
     } else if (!strcmp(arg, "--gen_all_targets")) {
diff --git a/flags.h b/flags.h
index 8c72fa5..d2fe923 100644
--- a/flags.h
+++ b/flags.h
@@ -26,6 +26,7 @@ using namespace std;
 struct Flags {
   bool detect_android_echo;
   bool dump_kati_stamp;
+  bool enable_kati_warnings;
   bool enable_stat_logs;
   bool gen_all_targets;
   bool gen_regen_rule;
diff --git a/func.cc b/func.cc
index 4de6de8..a194eb7 100644
--- a/func.cc
+++ b/func.cc
@@ -455,6 +455,10 @@ void EvalFunc(const vector<Value*>& args, Evaluator* ev, string*) {
   //const string text = args[0]->Eval(ev);
   string* text = new string;
   args[0]->Eval(ev, text);
+  if (ev->avoid_io()) {
+    KATI_WARN("%s:%d: *warning*: $(eval) in a recipe is not recommended: %s",
+              LOCF(ev->loc()), text->c_str());
+  }
   vector<Stmt*> stmts;
   Parse(*text, ev->loc(), &stmts);
   for (Stmt* stmt : stmts) {
diff --git a/log.h b/log.h
index 68e0ba1..6507bde 100644
--- a/log.h
+++ b/log.h
@@ -54,6 +54,11 @@ extern string* g_last_error;
     fprintf(stderr, "%s\n", StringPrintf(__VA_ARGS__).c_str()); \
   } while (0)
 
+#define KATI_WARN(...) do {                                             \
+    if (g_flags.enable_kati_warnings)                                   \
+      fprintf(stderr, "%s\n", StringPrintf(__VA_ARGS__).c_str());       \
+  } while (0)
+
 #define ERROR(...) do {                                                 \
     if (!g_log_no_exit) {                                               \
       fprintf(stderr, "%s\n", StringPrintf(__VA_ARGS__).c_str());       \