[scan-build] Value stored to 'angle' is never read

prop_matrix.c:209:5: warning: Value stored to 'angle' is never read
    angle = atan2 (prop->matrix->xy, prop->matrix->xx)*180/G_PI;
    ^       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
[scan-build] Value stored to 'alpha' is never read

diacolorselector.c:356:5: warning: Value stored to 'alpha' is never read
    alpha = MIN(alpha, 255);
    ^       ~~~~~~~~~~~~~~~
[scan-build] Value stored to 'stride' is never read

render_libart.c: In function 'draw_pixel_rect':
render_libart.c:399:7: warning: variable 'stride' set but not used [-Wunused-but-set-variable]
   int stride;
       ^
render_libart.c:405:3: warning: Value stored to 'stride' is never read
  stride = renderer->pixel_width*3;
  ^        ~~~~~~~~~~~~~~~~~~~~~~~
[scan-build] Value stored to 'ctm' [...] is never read etc.

pdf-import.cpp: In member function 'virtual void DiaOutputDev::updateFont(GfxState*)':
pdf-import.cpp:328:94: warning: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'GfxFont*' [-Wformat=]
     g_print ("Font 0x%08x: '%s' size=%g (* %g)\n", f, family, state->getTransformedFontSize());
                                                                                              ^
pdf-import.cpp:328:94: warning: format '%g' expects a matching 'double' argument [-Wformat=]
pdf-import.cpp:129:13: warning: Value stored to 'ctm' during its initialization is never read
    double *ctm = getDefCTM();
            ^~~   ~~~~~~~~~~~