Merge pull request #4860 from nioncode/fixPch

Fix missing PCH dependencies

mesonbuild/backend/ninjabackend.py

@@ -428,12 +428,7 @@ int dummy;
         # Generate rules for building the remaining source files in this target
         outname = self.get_target_filename(target)
         obj_list = []
-        use_pch = self.environment.coredata.base_options.get('b_pch', False)
         is_unity = self.is_unity(target)
-        if use_pch and target.has_pch():
-            pch_objects = self.generate_pch(target, outfile)
-        else:
-            pch_objects = []
         header_deps = []
         unity_src = []
         unity_deps = [] # Generated sources that must be built before compiling a Unity target.
@@ -486,6 +481,12 @@ int dummy;
                                                  header_deps=header_deps)
             obj_list.append(o)
 
+        use_pch = self.environment.coredata.base_options.get('b_pch', False)
+        if use_pch and target.has_pch():
+            pch_objects = self.generate_pch(target, outfile, header_deps=header_deps)
+        else:
+            pch_objects = []
+
         # Generate compilation targets for C sources generated from Vala
         # sources. This can be extended to other $LANG->C compilers later if
         # necessary. This needs to be separate for at least Vala
@@ -2208,12 +2209,7 @@ rule FORTRAN_DEP_HACK%s
             commands += compiler.get_module_outdir_args(self.get_target_private_dir(target))
 
         element = NinjaBuildElement(self.all_outputs, rel_obj, compiler_name, rel_src)
-        for d in header_deps:
-            if isinstance(d, File):
-                d = d.rel_to_builddir(self.build_to_src)
-            elif not self.has_dir_part(d):
-                d = os.path.join(self.get_target_private_dir(target), d)
-            element.add_dep(d)
+        self.add_header_deps(target, element, header_deps)
         for d in extra_deps:
             element.add_dep(d)
         for d in order_deps:
@@ -2222,7 +2218,14 @@ rule FORTRAN_DEP_HACK%s
             elif not self.has_dir_part(d):
                 d = os.path.join(self.get_target_private_dir(target), d)
             element.add_orderdep(d)
-        element.add_orderdep(pch_dep)
+        if compiler.id == 'msvc':
+            # MSVC does not show includes coming from the PCH with '/showIncludes',
+            # thus we must add an implicit dependency to the generated PCH.
+            element.add_dep(pch_dep)
+        else:
+            # All other compilers properly handle includes through the PCH, so only an
+            # orderdep is needed to make the initial build without depfile work.
+            element.add_orderdep(pch_dep)
         # Convert from GCC-style link argument naming to the naming used by the
         # current compiler.
         commands = commands.to_native()
@@ -2233,6 +2236,14 @@ rule FORTRAN_DEP_HACK%s
         element.write(outfile)
         return rel_obj
 
+    def add_header_deps(self, target, ninja_element, header_deps):
+        for d in header_deps:
+            if isinstance(d, File):
+                d = d.rel_to_builddir(self.build_to_src)
+            elif not self.has_dir_part(d):
+                d = os.path.join(self.get_target_private_dir(target), d)
+            ninja_element.add_dep(d)
+
     def has_dir_part(self, fname):
         # FIXME FIXME: The usage of this is a terrible and unreliable hack
         if isinstance(fname, File):
@@ -2263,6 +2274,7 @@ rule FORTRAN_DEP_HACK%s
         just_name = os.path.basename(header)
         (objname, pch_args) = compiler.gen_pch_args(just_name, source, dst)
         commands += pch_args
+        commands += self._generate_single_compile(target, compiler)
         commands += self.get_compile_debugfile_args(compiler, target, objname)
         dep = dst + '.' + compiler.get_depfile_suffix()
         return commands, dep, dst, [objname]
@@ -2278,7 +2290,7 @@ rule FORTRAN_DEP_HACK%s
         dep = dst + '.' + compiler.get_depfile_suffix()
         return commands, dep, dst, []  # Gcc does not create an object file during pch generation.
 
-    def generate_pch(self, target, outfile):
+    def generate_pch(self, target, outfile, header_deps=[]):
         cstr = ''
         pch_objects = []
         if target.is_cross:
@@ -2309,6 +2321,7 @@ rule FORTRAN_DEP_HACK%s
             elem = NinjaBuildElement(self.all_outputs, dst, rulename, src)
             if extradep is not None:
                 elem.add_dep(extradep)
+            self.add_header_deps(target, elem, header_deps)
             elem.add_item('ARGS', commands)
             elem.add_item('DEPFILE', dep)
             elem.write(outfile)

test cases/common/13 pch/generated/gen_custom.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python3
+import sys
+
+with open(sys.argv[1], 'w') as f:
+    f.write("#define FOO 0")

test cases/common/13 pch/generated/gen_generator.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python3
+import sys
+
+with open(sys.argv[1]) as f:
+    content = f.read()
+with open(sys.argv[2], 'w') as f:
+    f.write(content)

test cases/common/13 pch/generated/generated_generator.in

@@ -0,0 +1 @@
+#define BAR 0

test cases/common/13 pch/generated/meson.build

@@ -0,0 +1,16 @@
+cc = meson.get_compiler('c')
+cc_id = cc.get_id()
+if cc_id == 'lcc'
+  error('MESON_SKIP_TEST: Elbrus compiler does not support PCH.')
+endif
+
+generated_customTarget = custom_target('makeheader',
+  output: 'generated_customTarget.h',
+  command : [find_program('gen_custom.py'), '@OUTPUT0@'])
+
+generated_generator = generator(find_program('gen_generator.py'),
+  output: '@BASENAME@.h',
+  arguments: ['@INPUT@', '@OUTPUT@'])
+
+exe = executable('prog', 'prog.c', generated_customTarget, generated_generator.process('generated_generator.in'),
+  c_pch: ['pch/prog_pch.c', 'pch/prog.h'])

test cases/common/13 pch/generated/pch/prog.h

@@ -0,0 +1,2 @@
+#include "generated_customTarget.h"
+#include "generated_generator.h"

test cases/common/13 pch/generated/pch/prog_pch.c

@@ -0,0 +1,5 @@
+#if !defined(_MSC_VER)
+#error "This file is only for use with MSVC."
+#endif
+
+#include "prog.h"

test cases/common/13 pch/generated/prog.c

@@ -0,0 +1,6 @@
+// No includes here, they need to come from the PCH
+
+int main(int argc, char **argv) {
+    return FOO + BAR;
+}
+

test cases/common/13 pch/meson.build

@@ -2,6 +2,8 @@ project('pch test', 'c', 'cpp')
 
 subdir('c')
 subdir('cpp')
+subdir('generated')
+subdir('withIncludeDirectories')
 
 if meson.backend() == 'xcode'
   warning('Xcode backend only supports one precompiled header per target. Skipping "mixed" which has various precompiled headers.')

test cases/common/13 pch/withIncludeDirectories/include/lib/lib.h

@@ -0,0 +1 @@
+#include <stdio.h>

test cases/common/13 pch/withIncludeDirectories/meson.build

@@ -0,0 +1,9 @@
+cc = meson.get_compiler('c')
+cc_id = cc.get_id()
+if cc_id == 'lcc'
+  error('MESON_SKIP_TEST: Elbrus compiler does not support PCH.')
+endif
+
+exe = executable('prog', 'prog.c',
+  include_directories: 'include',
+  c_pch : ['pch/prog_pch.c', 'pch/prog.h'])

test cases/common/13 pch/withIncludeDirectories/pch/prog.h

@@ -0,0 +1 @@
+#include<lib/lib.h>

test cases/common/13 pch/withIncludeDirectories/pch/prog_pch.c

@@ -0,0 +1,5 @@
+#if !defined(_MSC_VER)
+#error "This file is only for use with MSVC."
+#endif
+
+#include "prog.h"

test cases/common/13 pch/withIncludeDirectories/prog.c

@@ -0,0 +1,10 @@
+// No includes here, they need to come from the PCH
+
+void func() {
+    fprintf(stdout, "This is a function that fails if stdio is not #included.\n");
+}
+
+int main(int argc, char **argv) {
+    return 0;
+}
+