Precompile headers: Treat headers as relative to current source directory

Teach `target_precompile_headers` to treat relative paths the
same way as `target_sources`.

Fixes: #19733

6 files changed, 22 insertions, 13 deletions

diff --git a/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake b/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake
index ee47980..59ee14b 100644
--- a/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake
@@ -4,7 +4,7 @@ project(DisabledPch C)
 add_library(foo foo.c)
 target_include_directories(foo PUBLIC include)
 target_precompile_headers(foo PUBLIC
-  foo.h
+  include/foo.h
   <stdio.h>
   \"string.h\"
 )
diff --git a/Tests/RunCMake/PrecompileHeaders/PchInterface-check.cmake b/Tests/RunCMake/PrecompileHeaders/PchInterface-check.cmake
index cbd6ede..caeb22b 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchInterface-check.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchInterface-check.cmake
@@ -18,19 +18,14 @@ endif()
 
 file(STRINGS ${foo_pch_header} foo_pch_header_strings)
 
-if (NOT "#include \"foo.h\"" IN_LIST foo_pch_header_strings OR
-    NOT "#include <stdio.h>" IN_LIST foo_pch_header_strings OR
-    NOT "#include \"string.h\"" IN_LIST foo_pch_header_strings)
-  set(RunCMake_TEST_FAILED "Generated foo pch header ${foo_pch_header} has bad content")
+if (NOT foo_pch_header_strings MATCHES ";#include \"[^\"]*PrecompileHeaders/include/foo.h\";#include \"foo2.h\";#include <stdio.h>;#include \"string.h\"(;|$)")
+  set(RunCMake_TEST_FAILED "Generated foo pch header\n  ${foo_pch_header}\nhas bad content:\n  ${foo_pch_header_strings}")
   return()
 endif()
 
 file(STRINGS ${foobar_pch_header} foobar_pch_header_strings)
 
-if (NOT "#include \"foo.h\"" IN_LIST foobar_pch_header_strings OR
-    NOT "#include <stdio.h>" IN_LIST foobar_pch_header_strings OR
-    NOT "#include \"string.h\"" IN_LIST foobar_pch_header_strings OR
-    NOT "#include \"bar.h\"" IN_LIST foobar_pch_header_strings)
-  set(RunCMake_TEST_FAILED "Generated foobar pch header ${foobar_pch_header} has bad content")
+if (NOT foobar_pch_header_strings MATCHES ";#include \"[^\"]*PrecompileHeaders/include/foo.h\";#include \"foo2.h\";#include <stdio.h>;#include \"string.h\";#include \"[^\"]*PrecompileHeaders/include/bar.h\"(;|$)")
+  set(RunCMake_TEST_FAILED "Generated foobar pch header\n  ${foobar_pch_header}\nhas bad content:\n  ${foobar_pch_header_strings}")
   return()
 endif()
diff --git a/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake b/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake
index 9041b09..a1e0792 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake
@@ -4,14 +4,15 @@ project(PchInterface C)
 add_library(foo foo.c)
 target_include_directories(foo PUBLIC include)
 target_precompile_headers(foo PUBLIC
-  foo.h
+  include/foo.h
+  \"foo2.h\"
   <stdio.h>
   \"string.h\"
 )
 
 add_library(bar INTERFACE)
 target_include_directories(bar INTERFACE include)
-target_precompile_headers(bar INTERFACE bar.h)
+target_precompile_headers(bar INTERFACE include/bar.h)
 
 add_executable(foobar foobar.c)
 target_link_libraries(foobar foo bar)
diff --git a/Tests/RunCMake/PrecompileHeaders/foo.c b/Tests/RunCMake/PrecompileHeaders/foo.c
index 974a248..85ea230 100644
--- a/Tests/RunCMake/PrecompileHeaders/foo.c
+++ b/Tests/RunCMake/PrecompileHeaders/foo.c
@@ -1,6 +1,12 @@
 #include "foo.h"
+#include "foo2.h"
 
 int foo()
 {
   return 0;
 }
+
+int foo2()
+{
+  return 0;
+}
diff --git a/Tests/RunCMake/PrecompileHeaders/foobar.c b/Tests/RunCMake/PrecompileHeaders/foobar.c
index 6dbf8ce..7a135ea 100644
--- a/Tests/RunCMake/PrecompileHeaders/foobar.c
+++ b/Tests/RunCMake/PrecompileHeaders/foobar.c
@@ -1,7 +1,8 @@
 #include "bar.h"
 #include "foo.h"
+#include "foo2.h"
 
 int main()
 {
-  return foo() + bar();
+  return foo() + foo2() + bar();
 }
diff --git a/Tests/RunCMake/PrecompileHeaders/include/foo2.h b/Tests/RunCMake/PrecompileHeaders/include/foo2.h
new file mode 100644
index 0000000..4bf9c81
--- /dev/null
+++ b/Tests/RunCMake/PrecompileHeaders/include/foo2.h
@@ -0,0 +1,6 @@
+#ifndef foo2_h
+#define foo2_h
+
+int foo2(void);
+
+#endif