Merge pull request #7435 from Shiffted/improve_module_errors

improve module errors

2 files changed, 26 insertions, 7 deletions

diff --git a/xmake/rules/c++/modules/scanner.lua b/xmake/rules/c++/modules/scanner.lua
index 2bcee1f12..72adea260 100644
--- a/xmake/rules/c++/modules/scanner.lua
+++ b/xmake/rules/c++/modules/scanner.lua
@@ -385,7 +385,7 @@ function _patch_sourcebatch(target, sourcebatch)
                 local strict = target:policy("build.c++.modules.reuse.strict") or
                                target:policy("build.c++.modules.tryreuse.discriminate_on_defines")
                 local dep = target:dep(fileconfig.from_dep)
-                assert(dep, "dep target <%s> for <%s> not found", fileconfig.from_dep, target:fullname())
+                assert(dep, "dep target(%s) for target(%s) not found", fileconfig.from_dep, target:fullname())
                 local can_reuse = nocheck or _are_flags_compatible(target, dep, sourcefile, {strict = strict})
                 if can_reuse then
                     local _reused, from = support.is_reused(dep, sourcefile)
@@ -556,7 +556,7 @@ function _schedule_module_dependencies_scan(target, jobgraph, sourcebatch)
                         local changed = memcache:get2(target:fullname(), "modules.changed")
                         if changed then
                             modules = modules or {}
-                            local moduleinfo = support.load_moduleinfo(target, sourcefile)
+                            local moduleinfo = assert(support.load_moduleinfo(target, sourcefile))
                             local module, headerunitsinfo = _parse_moduleinfo(target, moduleinfo)
                             modules[module.sourcefile] = module
                             for _, headerunitinfo in ipairs(headerunitsinfo) do
@@ -883,7 +883,15 @@ end
 
 function get_modules(target)
     local modules = support.localcache():get2(target:fullname(), "c++.modules")
-    assert(modules, "no modules! (" .. target:fullname() .. ")")
+    if not modules then
+        local targets = support.memcache():get("targets")
+        assert(targets, "module scanner did not run, maybe a custom `on_prepare()` script overrides the modules one.")
+
+        local target_fullname = target:fullname()
+        assert(targets[target_fullname], "module scanner did not run for target(%s), maybe a custom `on_prepare()` script overrides the modules one.", target_fullname)
+        assert(targets[target_fullname].finished_parsing, "target(%s): tried getting modules before scanner finished parsing.", target_fullname)
+        assert(false, "target(%s): no modules found!", target_fullname)
+    end
     return modules
 end
 
diff --git a/xmake/rules/c++/modules/support.lua b/xmake/rules/c++/modules/support.lua
index 0767c88af..1dd7625bb 100644
--- a/xmake/rules/c++/modules/support.lua
+++ b/xmake/rules/c++/modules/support.lua
@@ -281,15 +281,26 @@ end
 function load_moduleinfo(target, sourcefile)
     local reused, from = is_reused(target, sourcefile)
     local dependfile = reused and from:dependfile(sourcefile) or target:dependfile(sourcefile)
-    local moduleinfo
-    if os.isfile(dependfile) then
+
+    local is_file = os.isfile(dependfile)
+    if is_file then
         local data = io.load(dependfile)
         if data then
-            moduleinfo = json.decode(data.moduleinfo)
+            local moduleinfo = json.decode(data.moduleinfo)
             moduleinfo.sourcefile = sourcefile
+            return moduleinfo
         end
     end
-    return moduleinfo
+
+    local targets = memcache():get("targets")
+    local target_fullname = reused and from:fullname() or target:fullname()
+    if not (targets and targets[target_fullname]) then
+        return nil, string.format("module scanner did not run for target(%s), maybe a custom `on_prepare()` script overrides the modules one", target_fullname)
+    end
+    if not is_file then
+        return nil, string.format("target(%s): dependfile for '%s' not found at '%s'", target_fullname, sourcefile, dependfile)
+    end
+    return nil, string.format("target(%s): failed to load moduleinfo for '%s'", target_fullname, sourcefile)
 end
 
 function find_quote_header_file(sourcefile, file)