fix not propagating parseh aliases through pub use decls

src/analyze.cpp

@@ -2922,13 +2922,17 @@ static void add_symbols_from_import(CodeGen *g, AstNode *src_use_node, AstNode *
             continue;
         }
 
-        auto existing_entry = dst_use_node->owner->decls_scope->decl_table.put_unique(target_tld->name, target_tld);
+        // Note: target_tld->name is not necessarily equal to entry->key because
+        // of aliases that parseh uses.
+        Buf *target_tld_name = entry->key;
+
+        auto existing_entry = dst_use_node->owner->decls_scope->decl_table.put_unique(target_tld_name, target_tld);
         if (existing_entry) {
             Tld *existing_decl = existing_entry->value;
             if (existing_decl != target_tld) {
                 ErrorMsg *msg = add_node_error(g, dst_use_node,
                         buf_sprintf("import of '%s' overrides existing definition",
-                            buf_ptr(target_tld->name)));
+                            buf_ptr(target_tld_name)));
                 add_error_note(g, msg, existing_decl->source_node, buf_sprintf("previous definition here"));
                 add_error_note(g, msg, target_tld->source_node, buf_sprintf("imported definition here"));
             }
@@ -2956,6 +2960,12 @@ void resolve_use_decl(CodeGen *g, AstNode *node) {
 void preview_use_decl(CodeGen *g, AstNode *node) {
     assert(node->type == NodeTypeUse);
 
+    if (node->data.use.resolution == TldResolutionOk ||
+        node->data.use.resolution == TldResolutionInvalid)
+    {
+        return;
+    }
+
     node->data.use.resolution = TldResolutionResolving;
     IrInstruction *result = analyze_const_value(g, &node->owner->decls_scope->base,
         node->data.use.expr, g->builtin_types.entry_namespace, nullptr);

std/build.zig

@@ -979,7 +979,7 @@ pub const LibExeObjStep = struct {
 
         for (builder.include_paths.toSliceConst()) |include_path| {
             %%zig_args.append("-isystem");
-            %%zig_args.append(include_path);
+            %%zig_args.append(builder.pathFromRoot(include_path));
         }
 
         for (builder.rpaths.toSliceConst()) |rpath| {
@@ -1086,7 +1086,7 @@ pub const TestStep = struct {
 
         for (builder.include_paths.toSliceConst()) |include_path| {
             %%zig_args.append("-isystem");
-            %%zig_args.append(include_path);
+            %%zig_args.append(builder.pathFromRoot(include_path));
         }
 
         for (builder.rpaths.toSliceConst()) |rpath| {

test/build_examples.zig

@@ -9,4 +9,5 @@ pub fn addCases(cases: &tests.BuildExamplesContext) {
     cases.addBuildFile("example/mix_o_files/build.zig");
     cases.addBuildFile("test/standalone/issue_339/build.zig");
     cases.addBuildFile("test/standalone/pkg_import/build.zig");
+    cases.addBuildFile("test/standalone/use_alias/build.zig");
 }

test/standalone/use_alias/build.zig

@@ -0,0 +1,11 @@
+const Builder = @import("std").build.Builder;
+
+pub fn build(b: &Builder) {
+    b.addCIncludePath(".");
+
+    const main = b.addTest("main.zig");
+    main.setBuildMode(b.standardReleaseOptions());
+
+    const test_step = b.step("test", "Test it");
+    test_step.dependOn(&main.step);
+}

test/standalone/use_alias/c.zig

@@ -0,0 +1 @@
+pub use @cImport(@cInclude("foo.h"));

test/standalone/use_alias/foo.h

@@ -0,0 +1,4 @@
+struct Foo {
+    int a;
+    int b;
+};

test/standalone/use_alias/main.zig

@@ -0,0 +1,10 @@
+const c = @import("c.zig");
+const assert = @import("std").debug.assert;
+
+test "symbol exists" {
+    var foo = c.Foo {
+        .a = 1,
+        .b = 1,
+    };
+    assert(foo.a + foo.b == 2);
+}