Re-introduced Yosys::readsome() helper function

(f.read() + f.gcount() made problems with lines > 16kB)

frontends/ilang/ilang_lexer.l

@@ -35,11 +35,7 @@
 USING_YOSYS_NAMESPACE
 
 #define YY_INPUT(buf,result,max_size) \
-	do { \
-		ILANG_FRONTEND::lexin->read(buf, max_size-1); \
-		result = ILANG_FRONTEND::lexin->gcount(); \
-		if (result >= 0) buf[result] = '\0'; \
-	} while (0)
+	result = readsome(*ILANG_FRONTEND::lexin, buf, max_size)
 
 %}
 

frontends/verilog/preproc.cc

@@ -196,16 +196,14 @@ static std::string next_token(bool pass_newline = false)
 static void input_file(std::istream &f, std::string filename)
 {
 	char buffer[513];
+	int rc;
 
 	insert_input("");
 	auto it = input_buffer.begin();
 
 	input_buffer.insert(it, "`file_push " + filename + "\n");
-	while (1) {
-		f.read(buffer, sizeof(buffer)-1);
-		if (f.gcount() <= 0)
-			break;
-		buffer[f.gcount()] = 0;
+	while ((rc = readsome(f, buffer, sizeof(buffer)-1)) > 0) {
+		buffer[rc] = 0;
 		input_buffer.insert(it, buffer);
 	}
 	input_buffer.insert(it, "\n`file_pop\n");

frontends/verilog/verilog_lexer.l

@@ -64,11 +64,7 @@ YOSYS_NAMESPACE_END
 	return TOK_ID;
 
 #define YY_INPUT(buf,result,max_size) \
-	do { \
-		lexin->read(buf, max_size-1); \
-		result = lexin->gcount(); \
-		if (result >= 0) buf[result] = '\0'; \
-	} while (0)
+	result = readsome(*VERILOG_FRONTEND::lexin, buf, max_size)
 
 %}
 

kernel/yosys.cc

@@ -97,6 +97,22 @@ std::string vstringf(const char *fmt, va_list ap)
 	return string;
 }
 
+int readsome(std::istream &f, char *s, int n)
+{
+	int rc = f.readsome(s, n);
+
+	// f.readsome() sometimes returns 0 on a non-empty stream..
+	if (rc == 0) {
+		int c = f.get();
+		if (c != EOF) {
+			*s = c;
+			rc = 1;
+		}
+	}
+
+	return rc;
+}
+
 std::string next_token(std::string &text, const char *sep)
 {
 	size_t pos_begin = text.find_first_not_of(sep);

kernel/yosys.h

@@ -127,6 +127,7 @@ namespace RTLIL {
 
 std::string stringf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
 std::string vstringf(const char *fmt, va_list ap);
+int readsome(std::istream &f, char *s, int n);
 std::string next_token(std::string &text, const char *sep);
 bool patmatch(const char *pattern, const char *string);
 int run_command(const std::string &command, std::function<void(const std::string&)> process_line = std::function<void(const std::string&)>());

passes/cmds/write_file.cc

@@ -68,13 +68,10 @@ struct WriteFileFrontend : public Frontend {
 
 		FILE *of = fopen(output_filename.c_str(), append_mode ? "a" : "w");
 		char buffer[64 * 1024];
+		int bytes;
 
-		while (1) {
-			f->read(buffer, sizeof(buffer));
-			if (f->gcount() <= 0)
-				break;
-			fwrite(buffer, f->gcount(), 1, of);
-		}
+		while (0 < (bytes = readsome(*f, buffer, sizeof(buffer))))
+			fwrite(buffer, bytes, 1, of);
 
 		fclose(of);
 	}