From 6c0e3a3272340a0c0cfe44ebad7b9bc39c981b28 Mon Sep 17 00:00:00 2001
From: Alex Bryan <abryancs@gmail.com>
Date: Fri, 19 Jan 2024 01:56:11 -0500
Subject: [PATCH] Fix #2698: cImportPaths doesn't work with dmd and ldc

---
 changelog/fix-cimport-paths.dd                             | 3 +++
 source/dub/compilers/dmd.d                                 | 2 +-
 source/dub/compilers/ldc.d                                 | 2 +-
 .../c_headers/foo.h                                        | 6 ++++++
 test/issue2698-cimportpaths-broken-with-dmd-ldc/dub.sdl    | 5 +++++
 .../source/app.d                                           | 7 +++++++
 .../source/foo.c                                           | 1 +
 7 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 changelog/fix-cimport-paths.dd
 create mode 100644 test/issue2698-cimportpaths-broken-with-dmd-ldc/c_headers/foo.h
 create mode 100644 test/issue2698-cimportpaths-broken-with-dmd-ldc/dub.sdl
 create mode 100644 test/issue2698-cimportpaths-broken-with-dmd-ldc/source/app.d
 create mode 100644 test/issue2698-cimportpaths-broken-with-dmd-ldc/source/foo.c

diff --git a/changelog/fix-cimport-paths.dd b/changelog/fix-cimport-paths.dd
new file mode 100644
index 000000000..7bab23dc4
--- /dev/null
+++ b/changelog/fix-cimport-paths.dd
@@ -0,0 +1,3 @@
+Fix issue where cImportPaths wasn't working with dmd and ldc
+
+dub was passing -I<import path> instead of -P-I<import path> as is required by those compilers
diff --git a/source/dub/compilers/dmd.d b/source/dub/compilers/dmd.d
index 5b59d2b99..8d58f515c 100644
--- a/source/dub/compilers/dmd.d
+++ b/source/dub/compilers/dmd.d
@@ -257,7 +257,7 @@ config    /etc/dmd.conf
 		}
 
 		if (!(fields & BuildSetting.cImportPaths)) {
-			settings.addDFlags(settings.cImportPaths.map!(s => "-I"~s)().array());
+			settings.addDFlags(settings.cImportPaths.map!(s => "-P-I"~s)().array());
 			settings.cImportPaths = null;
 		}
 
diff --git a/source/dub/compilers/ldc.d b/source/dub/compilers/ldc.d
index 3959df615..bd6193346 100644
--- a/source/dub/compilers/ldc.d
+++ b/source/dub/compilers/ldc.d
@@ -137,7 +137,7 @@ config    /etc/ldc2.conf (x86_64-pc-linux-gnu)
 		}
 
 		if (!(fields & BuildSetting.cImportPaths)) {
-			settings.addDFlags(settings.cImportPaths.map!(s => "-I"~s)().array());
+			settings.addDFlags(settings.cImportPaths.map!(s => "-P-I"~s)().array());
 			settings.cImportPaths = null;
 		}
 
diff --git a/test/issue2698-cimportpaths-broken-with-dmd-ldc/c_headers/foo.h b/test/issue2698-cimportpaths-broken-with-dmd-ldc/c_headers/foo.h
new file mode 100644
index 000000000..dab60af48
--- /dev/null
+++ b/test/issue2698-cimportpaths-broken-with-dmd-ldc/c_headers/foo.h
@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int bar(void)
+{
+	printf("func bar in foo.h\n");
+}
diff --git a/test/issue2698-cimportpaths-broken-with-dmd-ldc/dub.sdl b/test/issue2698-cimportpaths-broken-with-dmd-ldc/dub.sdl
new file mode 100644
index 000000000..837f5274d
--- /dev/null
+++ b/test/issue2698-cimportpaths-broken-with-dmd-ldc/dub.sdl
@@ -0,0 +1,5 @@
+name "issue2698-cimportpaths-broken-with-dmd-ldc"
+description "test issue 2698"
+authors "alexander bryan"
+cSourcePaths "source"
+cImportPaths "c_headers"
diff --git a/test/issue2698-cimportpaths-broken-with-dmd-ldc/source/app.d b/test/issue2698-cimportpaths-broken-with-dmd-ldc/source/app.d
new file mode 100644
index 000000000..6413a1cd8
--- /dev/null
+++ b/test/issue2698-cimportpaths-broken-with-dmd-ldc/source/app.d
@@ -0,0 +1,7 @@
+import std.stdio;
+import foo;
+
+void main()
+{
+	bar();
+}
diff --git a/test/issue2698-cimportpaths-broken-with-dmd-ldc/source/foo.c b/test/issue2698-cimportpaths-broken-with-dmd-ldc/source/foo.c
new file mode 100644
index 000000000..f4de601ff
--- /dev/null
+++ b/test/issue2698-cimportpaths-broken-with-dmd-ldc/source/foo.c
@@ -0,0 +1 @@
+#include "foo.h"