builder: fix Windows pkgconfig paths and MSVC flags (#26631)

Author: quaesitor-scientiam

vlib/v/builder/msvc_windows.v

@@ -523,13 +523,116 @@ mut:
 	other_flags []string
 }
 
+fn strip_quotes(value string) string {
+	if value.len >= 2 && value[0] == `"` && value[value.len - 1] == `"` {
+		return value[1..value.len - 1]
+	}
+	return value
+}
+
+fn apply_gnu_flag_to_msvc(value string, mut inc_paths []string, mut lib_paths []string, mut real_libs []string) bool {
+	v := strip_quotes(value)
+	if v.starts_with('-I') && v.len > 2 {
+		path := v[2..]
+		inc_paths << '/I"${os.real_path(path)}"'
+		return true
+	}
+	if v.starts_with('-L') && v.len > 2 {
+		path := v[2..]
+		lib_paths << path
+		lib_paths << path + os.path_separator + 'msvc'
+		return true
+	}
+	if v.starts_with('-l') && v.len > 2 {
+		mut lib := v[2..]
+		if lib.starts_with(':') && lib.len > 1 {
+			lib = lib[1..]
+		}
+		if !lib.ends_with('.lib') {
+			lib += '.lib'
+		}
+		real_libs << lib
+		return true
+	}
+	if v.starts_with('-Wl,') {
+		mut consumed := false
+		for part in v[4..].split(',') {
+			if apply_gnu_flag_to_msvc(part, mut inc_paths, mut lib_paths, mut real_libs) {
+				consumed = true
+			}
+		}
+		return consumed
+	}
+	return false
+}
+
+fn split_and_apply_gnu_flags(value string, mut inc_paths []string, mut lib_paths []string, mut real_libs []string) (bool, string) {
+	if !value.contains(' ') {
+		if apply_gnu_flag_to_msvc(value, mut inc_paths, mut lib_paths, mut real_libs) {
+			return true, ''
+		}
+		return false, value
+	}
+	parts := split_quoted_flags(value)
+	mut consumed := false
+	mut leftovers := []string{}
+	for part in parts {
+		if part == '' {
+			continue
+		}
+		if apply_gnu_flag_to_msvc(part, mut inc_paths, mut lib_paths, mut real_libs) {
+			consumed = true
+		} else {
+			leftovers << strip_quotes(part)
+		}
+	}
+	if consumed {
+		return true, leftovers.join(' ')
+	}
+	return false, value
+}
+
+fn split_quoted_flags(value string) []string {
+	mut parts := []string{}
+	mut buf := []u8{}
+	mut in_quote := false
+	for ch in value {
+		if ch == `"` {
+			in_quote = !in_quote
+			continue
+		}
+		if !in_quote && ch == ` ` {
+			if buf.len > 0 {
+				parts << buf.bytestr()
+				buf = []u8{}
+			}
+			continue
+		}
+		buf << ch
+	}
+	if buf.len > 0 {
+		parts << buf.bytestr()
+	}
+	return parts
+}
+
 pub fn (mut v Builder) msvc_string_flags(cflags []cflag.CFlag) MsvcStringFlags {
 	mut real_libs := []string{}
 	mut inc_paths := []string{}
 	mut lib_paths := []string{}
 	mut defines := []string{}
 	mut other_flags := []string{}
 	for flag in cflags {
+		if flag.name == '' {
+			consumed, leftover := split_and_apply_gnu_flags(flag.value, mut inc_paths, mut
+				lib_paths, mut real_libs)
+			if consumed {
+				if leftover != '' {
+					other_flags << strip_quotes(leftover)
+				}
+				continue
+			}
+		}
 		// println('fl: ${flag.name} | flag arg: ${flag.value}')
 		// We need to see if the flag contains -l
 		// -l isnt recognised and these libs will be passed straight to the linker
@@ -540,14 +643,29 @@ pub fn (mut v Builder) msvc_string_flags(cflags []cflag.CFlag) MsvcStringFlags {
 			}
 			// MSVC has no method of linking against a .dll
 			// TODO: we should look for .defs aswell
-			lib_lib := flag.value + '.lib'
-			real_libs << lib_lib
+			parts := split_quoted_flags(flag.value)
+			if parts.len > 0 {
+				mut lib := strip_quotes(parts[0])
+				if lib.starts_with(':') && lib.len > 1 {
+					lib = lib[1..]
+				}
+				if !lib.ends_with('.lib') {
+					lib += '.lib'
+				}
+				real_libs << lib
+				if parts.len > 1 {
+					_, leftover := split_and_apply_gnu_flags(parts[1..].join(' '), mut
+						inc_paths, mut lib_paths, mut real_libs)
+					if leftover != '' {
+						other_flags << strip_quotes(leftover)
+					}
+				}
+			}
 		} else if flag.name == '-I' {
-			inc_paths << flag.format() or { continue }
+			inc_paths << '/I"${os.real_path(flag.value)}"'
 		} else if flag.name == '-D' {
 			defines << '/D${flag.value}'
 		} else if flag.name == '-L' {
-			// TODO: use flag.format() here as well; `#flag -L$when_first_existing(...)` is a more explicit way to achieve the same
 			lib_paths << flag.value
 			lib_paths << flag.value + os.path_separator + 'msvc'
 			// The above allows putting msvc specific .lib files in a subfolder msvc/ ,
@@ -567,7 +685,15 @@ pub fn (mut v Builder) msvc_string_flags(cflags []cflag.CFlag) MsvcStringFlags {
 		} else if flag.value.starts_with('-D') {
 			defines << '/D${flag.value[2..]}'
 		} else {
-			other_flags << flag.value
+			consumed, leftover := split_and_apply_gnu_flags(flag.value, mut inc_paths, mut
+				lib_paths, mut real_libs)
+			if consumed {
+				if leftover != '' {
+					other_flags << strip_quotes(leftover)
+				}
+				continue
+			}
+			other_flags << strip_quotes(flag.value)
 		}
 	}
 	mut lpaths := []string{}

vlib/v/pkgconfig/pkgconfig.v

@@ -100,6 +100,7 @@ fn (mut pc PkgConfig) setvar(line string) {
 
 fn (mut pc PkgConfig) parse(file string) bool {
 	pc.file_path = file
+	pc.vars['pcfiledir'] = os.real_path(os.dir(file))
 	data := os.read_file(file) or { return false }
 	if pc.options.debug {
 		eprintln(data)

vlib/v/pkgconfig/pkgconfig_test.v

@@ -57,6 +57,7 @@ fn test_samples() {
 			assert x.cflags == ['-I/usr/include', '-pthread', '-I/usr/include/glib-2.0',
 				'-I/usr/lib/x86_64-linux-gnu/glib-2.0/include']
 			assert x.vars == {
+				'pcfiledir':         samples_dir
 				'prefix':            '/usr'
 				'libdir':            '/usr/lib/x86_64-linux-gnu'
 				'includedir':        '/usr/include'
@@ -76,6 +77,7 @@ fn test_samples() {
 			assert x.cflags == ['-I/usr/include/glib-2.0',
 				'-I/usr/lib/x86_64-linux-gnu/glib-2.0/include', '-I/usr/include']
 			assert x.vars == {
+				'pcfiledir':       samples_dir
 				'prefix':          '/usr'
 				'libdir':          '/usr/lib/x86_64-linux-gnu'
 				'includedir':      '/usr/include'