When a shader fails compilation, add some line numbers.

[movit] / util.cpp

diff --git a/util.cpp b/util.cpp
index 2f6e6947b28029b9830e1d9aee78e595580a249b..9b018825d333e269e3e0007b0300165af563b28f 100644 (file)
--- a/util.cpp
+++ b/util.cpp
@@ -157,7 +157,19 @@ GLuint compile_shader(const string &shader_src, GLenum type)
        GLint status;
        glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
        if (status == GL_FALSE) {
-               fprintf(stderr, "Failed to compile shader: %s\n", shader_src.c_str());
+               // Add some line numbers to easier identify compile errors.
+               string src_with_lines = "/*   1 */ ";
+               size_t lineno = 1;
+               for (char ch : shader_src) {
+                       src_with_lines.push_back(ch);
+                       if (ch == '\n') {
+                               char buf[32];
+                               snprintf(buf, sizeof(buf), "/* %3zu */ ", ++lineno);
+                               src_with_lines += buf;
+                       }
+               }
+
+               fprintf(stderr, "Failed to compile shader:\n%s\n", src_with_lines.c_str());
                exit(1);
        }