pkg: add support for 'simple' Provides rule entries (#95)

Makefile.am

@@ -55,7 +55,8 @@ EXTRA_DIST =	\
 		tests/lib1/isystem.pc \
 		tests/lib1/depgraph-break.pc \
 		tests/lib1/cflags-whitespace.pc \
-		tests/lib1/provides.pc
+		tests/lib1/provides.pc \
+		tests/lib1/provides-request-simple.pc
 
 pkginclude_HEADERS = libpkgconf/bsdstubs.h libpkgconf/iter.h libpkgconf/libpkgconf.h libpkgconf/stdinc.h
 libpkgconf_la_SOURCES  =	\

libpkgconf/libpkgconf.h

@@ -119,6 +119,7 @@ struct pkgconf_pkg_ {
 #define PKGCONF_PKG_PKGF_MUNGE_SYSROOT_PREFIX		0x080
 #define PKGCONF_PKG_PKGF_SKIP_ERRORS			0x100
 #define PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE		0x200
+#define PKGCONF_PKG_PKGF_SKIP_PROVIDES			0x400
 
 #define PKGCONF_PKG_ERRF_OK			0x0
 #define PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND	0x1

libpkgconf/pkg.c

@@ -876,6 +876,65 @@ pkgconf_pkg_comparator_lookup_by_name(const char *name)
 	return (p != NULL) ? p->compare : PKGCONF_CMP_ANY;
 }
 
+typedef struct {
+	pkgconf_dependency_t *pkgdep;
+	unsigned int flags;
+} pkgconf_pkg_scan_providers_ctx_t;
+
+/*
+ * pkgconf_pkg_scan_provides_entry(pkg, ctx)
+ *
+ * attempt to match a single package's Provides rules against the requested dependency node.
+ *
+ * XXX: implement support for version comparisons using backwards dependency version checks,
+ *      right now, we only support Provides rules that are PKGCONF_CMP_ANY as this is still
+ *      proof-of-concept.
+ */
+static bool
+pkgconf_pkg_scan_provides_entry(const pkgconf_pkg_t *pkg, const pkgconf_pkg_scan_providers_ctx_t *ctx)
+{
+	const pkgconf_dependency_t *pkgdep = ctx->pkgdep;
+	pkgconf_node_t *node;
+
+	switch (pkgdep->compare)
+	{
+	case PKGCONF_CMP_ANY:
+		PKGCONF_FOREACH_LIST_ENTRY(pkg->provides.head, node)
+		{
+			const pkgconf_dependency_t *provider = node->data;
+			if (!strcmp(provider->package, pkgdep->package))
+				return true;
+		}
+		break;
+	}
+
+	return false;
+}
+
+/*
+ * pkgconf_pkg_scan_providers(pkgdep, flags, eflags)
+ *
+ * scan all available packages to see if a Provides rule matches the pkgdep.
+ */
+static pkgconf_pkg_t *
+pkgconf_pkg_scan_providers(pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
+{
+	pkgconf_pkg_t *pkg;
+	pkgconf_pkg_scan_providers_ctx_t ctx = {
+		.pkgdep = pkgdep,
+		.flags = flags
+	};
+
+	pkg = pkgconf_scan_all(&ctx, (pkgconf_pkg_iteration_func_t) pkgconf_pkg_scan_provides_entry);
+	if (pkg != NULL)
+		return pkg;
+
+	if (eflags != NULL)
+		*eflags |= PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND;
+
+	return NULL;
+}
+
 /*
  * pkg_verify_dependency(pkgdep, flags)
  *
@@ -893,10 +952,15 @@ pkgconf_pkg_verify_dependency(pkgconf_dependency_t *pkgdep, unsigned int flags,
 	pkg = pkgconf_pkg_find(pkgdep->package, flags);
 	if (pkg == NULL)
 	{
-		if (eflags != NULL)
+		if (flags & PKGCONF_PKG_PKGF_SKIP_PROVIDES)
-			*eflags |= PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND;
+		{
+			if (eflags != NULL)
+				*eflags |= PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND;
 
-		return NULL;
+			return NULL;
+		}
+
+		return pkgconf_pkg_scan_providers(pkgdep, flags, eflags);
 	}
 
 	if (pkg->id == NULL)

tests/lib1/provides-request-simple.pc

@@ -0,0 +1,6 @@
+Name: provides-request-simple
+Description: A testing pkg-config file
+Version: 1.2.3
+Libs: -lfoo
+Cflags: -I/usr/include/foo
+Requires: provides-test-foo

tests/run.sh.in

@@ -286,16 +286,19 @@ run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --cflags prefix-foo1 prefix-foo
 run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --variable=typelibdir --define-variable='libdir=\${libdir}' typelibdir" \
 	"\${libdir}/typelibdir"
 
-run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --print-provides provides" \
-	"provides = 1.2.3" "provides-test-foo = 1.0.0" "provides-test-baz >= 1.1.0" "provides-test-moo <= 1.2.0"
-
 run_test "PKG_CONFIG_PATH='${selfdir}/lib1' PKG_CONFIG_SYSROOT_DIR='/test' ${1} --cflags isystem" \
 	"-isystem /test/opt/bad/include"
 
 run_test "PKG_CONFIG_PATH='${selfdir}/lib1' PKG_CONFIG_SYSROOT_DIR='/test' ${1} --cflags cflags-whitespace" \
 	"-I /test/opt/bad/include"
 
-# 10) tests for internal getopt implementation with options at the end
+# 10) tests for Provides system
+run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --print-provides provides" \
+	"provides = 1.2.3" "provides-test-foo = 1.0.0" "provides-test-baz >= 1.1.0" "provides-test-moo <= 1.2.0"
+run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} --libs provides-request-simple" \
+	"-lfoo"
+
+# 11) tests for internal getopt implementation with options at the end
 if [ "x@STRICT_MODE@" = "xno" ]; then
 	run_test "PKG_CONFIG_PATH='${selfdir}/lib1' ${1} foo --libs" \
 		'-lfoo'