Can you understand protoc running with no errors, but not generating source files?

Question

I have downloaded protocol buffers (2.6.0) and I am trying to compile the .proto files. I run the following from inside the downloaded protobuf-2.6.0 directory

$ protoc --version
libprotoc-2.6.0

$ cd java
$ protoc --java_out=src/main/java -I../src ../src/google/protobuf/descriptor.proto

$ ls src/main/java
com

There are no errors on the protoc command, but the compilation should have generated source files in src/main/java/google/protobuf

--java_out specifies where generated Java source files should go
-I specifies the directory where imports can be found

I see nothing wrong with my command. Any ideas?

Thanks

Ah! This question is not asking the right thing. The source files are generated, but the package differs to what I expected. The descriptor.proto file has 'package google.protobuf', but the sources are put in 'com.google.protubuf'. Should I delete the question, or edit it? — doc
– doc, Commented Dec 2, 2014 at 13:39

SMA · Accepted Answer · 2014-12-02 13:28:09Z

1

Your -I option seems incomplete. It should be

-I../src/google/protobuf/

answered Dec 2, 2014 at 13:28

SMA

37.2k8 gold badges53 silver badges76 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

doc Over a year ago

Thanks - unfortunately, adding the full path to the import statement did not change the result (I assumed it searched -I recursively).

Kenton Varda Over a year ago

This answer is incorrect. The question's original -I../src is correct. -I should specify the "canonical source root". Since the file is always imported as import "google/protobuf/descriptor.proto;, the -I flag should NOT include google/protobuf. (In this case, the difference is subtle. Specifying -I../src/google/protobuf will not cause an error, but the source code's embedded descriptor will be wrong.)

doc · Accepted Answer · 2014-12-03 12:09:46Z

1

The question premise is false. The sources are being generated, but go under src/main/java/com/google/protobuf rather than src/main/java/google/protobuf as one might expect from the package name in descriptor.proto.

Edit - the java package name is given in the proto file like so:

package google.protobuf;
option java_package = "com.google.protobuf";

edited Dec 3, 2014 at 12:09

answered Dec 2, 2014 at 14:44

doc

8271 gold badge7 silver badges28 bronze badges

1 Comment

Kenton Varda Over a year ago

Correct. Java code is expected to be organized by Java package name. In contrast, C++ generated code will be organized according to the directory structure of the input .proto files.

Collectives™ on Stack Overflow

Can you understand protoc running with no errors, but not generating source files?

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related