Can override install directory on a target-by-target basis.

backends.py

@@ -547,10 +547,12 @@ class NinjaBackend(Backend):
         should_strip = self.environment.coredata.strip
         for t in self.build.get_targets().values():
             if t.should_install():
-                if isinstance(t, build.Executable):
-                    outdir = bindir
-                else:
-                    outdir = libdir
+                outdir = t.get_custom_install_dir()
+                if outdir is None:
+                    if isinstance(t, build.Executable):
+                        outdir = bindir
+                    else:
+                        outdir = libdir
                 i = [self.get_target_filename(t), outdir, t.get_aliaslist(), should_strip]
                 d.targets.append(i)
 
@@ -571,7 +573,9 @@ class NinjaBackend(Backend):
         headers = self.build.get_headers()
 
         for h in headers:
-            outdir = os.path.join(incroot, h.get_subdir())
+            outdir = h.get_custom_install_dir()
+            if outdir is None:
+                outdir = os.path.join(incroot, h.get_subdir())
             for f in h.get_sources():
                 abspath = os.path.join(self.environment.get_source_dir(), f) # FIXME
                 i = [abspath, outdir]

build.py

@@ -194,6 +194,9 @@ class BuildTarget():
         for i in self.link_targets:
             result += i.get_rpaths()
         return result
+    
+    def get_custom_install_dir(self):
+        return self.custom_install_dir
 
     def process_kwargs(self, kwargs):
         self.copy_kwargs(kwargs)
@@ -236,6 +239,10 @@ class BuildTarget():
         if not isinstance(deplist, list):
             deplist = [deplist]
         self.add_external_deps(deplist)
+        self.custom_install_dir = kwargs.get('install_dir', None)
+        if self.custom_install_dir is not None:
+            if not isinstance(self.custom_install_dir, str):
+                raise InvalidArguments('Custom_install_dir must be a string')
 
     def get_subdir(self):
         return self.subdir

interpreter.py

@@ -52,13 +52,13 @@ class TryRunResultHolder(InterpreterObject):
         
     def returncode_method(self, args, kwargs):
         return self.res.returncode
-    
+
     def compiled_method(self, args, kwargs):
         return self.res.compiled
     
     def stdout_method(self, args, kwargs):
         return self.res.stdout
-    
+
     def stderr_method(self, args, kwargs):
         return self.res.stderr
 
@@ -267,6 +267,10 @@ class Headers(InterpreterObject):
         InterpreterObject.__init__(self)
         self.sources = sources
         self.subdir = kwargs.get('subdir', '')
+        self.custom_install_dir = kwargs.get('install_dir', None)
+        if self.custom_install_dir is not None:
+            if not isinstance(self.custom_install_dir, str):
+                raise InterpreterException('Custom_install_dir must be a string.')
 
     def set_subdir(self, subdir):
         self.subdir = subdir
@@ -277,6 +281,9 @@ class Headers(InterpreterObject):
     def get_sources(self):
         return self.sources
 
+    def get_custom_install_dir(self):
+        return self.custom_install_dir
+
 class Data(InterpreterObject):
     def __init__(self, subdir, sources, kwargs):
         InterpreterObject.__init__(self)

test cases/common/52 custom install dirs/installed_files.txt

@@ -0,0 +1,2 @@
+dib/dab/dub/prog
+some/dir/sample.h

test cases/common/52 custom install dirs/meson.build

@@ -0,0 +1,4 @@
+project('custom install dirs', 'c')
+
+executable('prog', 'prog.c', install : true, install_dir : 'dib/dab/dub')
+headers('sample.h', install_dir : 'some/dir')

test cases/common/52 custom install dirs/prog.c

@@ -0,0 +1,3 @@
+int main(int argc, char **arv) {
+    return 0;
+}

test cases/common/52 custom install dirs/sample.h

@@ -0,0 +1,6 @@
+#ifndef SAMPLE_H
+#define SAMPLE_H
+
+int wackiness();
+
+#endif