Merge pull request #1904 from certik/import_fix

certik · web-flow · commit 5a97ed09b6e6 · 2023-06-14T08:21:16.000-06:00
Allow duplicate imports
diff --git a/integration_tests/modules_02.py b/integration_tests/modules_02.py
@@ -1,4 +1,4 @@
-from modules_02b import f
+from modules_02b import f, f
 from lpython import i32
 
 def main0():
diff --git a/src/lpython/semantics/python_ast_to_asr.cpp b/src/lpython/semantics/python_ast_to_asr.cpp
@@ -4245,14 +4245,28 @@ class SymbolTableVisitor : public CommonVisitor<SymbolTableVisitor> {
         }
 
         ASR::Module_t *m = ASR::down_cast<ASR::Module_t>(t);
+        int i=-1;
         for (auto &remote_sym : mod_symbols) {
+            i++;
             if( procedures_db.is_function_to_be_ignored(msym, remote_sym) ) {
                 continue ;
             }
             std::string new_sym_name = ASRUtils::get_mangled_name(m, remote_sym);
             ASR::symbol_t *t = import_from_module(al, m, current_scope, msym,
                                 remote_sym, new_sym_name, x.base.base.loc, true);
-            current_scope->add_symbol(new_sym_name, t);
+            if (current_scope->get_scope().find(new_sym_name) != current_scope->get_scope().end()) {
+                ASR::symbol_t *old_sym = current_scope->get_scope().find(new_sym_name)->second;
+                diag.add(diag::Diagnostic(
+                    "The symbol '" + new_sym_name + "' imported from " + std::string(m->m_name) +" will shadow the existing symbol '" + new_sym_name + "'",
+                    diag::Level::Warning, diag::Stage::Semantic, {
+                        diag::Label("new symbol", {x.m_names[i].loc}),
+                        diag::Label("old symbol implementation", {old_sym->base.loc}),
+                    })
+                );
+                current_scope->overwrite_symbol(new_sym_name, t);
+            } else {
+                current_scope->add_symbol(new_sym_name, t);
+            }
         }
 
         tmp = nullptr;
diff --git a/tests/reference/asr-modules_02-ec92e6f.json b/tests/reference/asr-modules_02-ec92e6f.json
@@ -2,12 +2,12 @@
     "basename": "asr-modules_02-ec92e6f",
     "cmd": "lpython --show-asr --no-color {infile} -o {outfile}",
     "infile": "tests/../integration_tests/modules_02.py",
-    "infile_hash": "dcb00ac27cbbcdec61d81f1df9e852ba81a2197e7804ec89cab76e44",
+    "infile_hash": "c3ce0b2b9780f27f787297f75e5477e990481b962dcee420809540e0",
     "outfile": null,
     "outfile_hash": null,
     "stdout": "asr-modules_02-ec92e6f.stdout",
     "stdout_hash": "2b9767d477601b562ca13e1d770d84bafad8f2647fb778d52fc20d0d",
-    "stderr": null,
-    "stderr_hash": null,
+    "stderr": "asr-modules_02-ec92e6f.stderr",
+    "stderr_hash": "910bed77716460a8f8712eac5e5818c55b7744f45a4a36aa257f3527",
     "returncode": 0
 }
diff --git a/tests/reference/asr-modules_02-ec92e6f.stderr b/tests/reference/asr-modules_02-ec92e6f.stderr
@@ -0,0 +1,14 @@
+warning: The symbol 'f' imported from modules_02b will shadow the existing symbol 'f'
+ --> tests/../integration_tests/modules_02.py:1:28
+  |
+1 | from modules_02b import f, f
+  |                            ^ new symbol
+
+ --> tests/../integration_tests/modules_02b.py:3:1 - 5:16
+  |
+3 |    def f():
+  |    ^^^^^^^^...
+...
+  |
+5 |        print("f()")
+  | ...^^^^^^^^^^^^^^^^ old symbol implementation
diff --git a/tests/reference/asr_json-modules_02-70a491a.json b/tests/reference/asr_json-modules_02-70a491a.json
@@ -2,12 +2,12 @@
     "basename": "asr_json-modules_02-70a491a",
     "cmd": "lpython --show-asr --json {infile} -o {outfile}",
     "infile": "tests/../integration_tests/modules_02.py",
-    "infile_hash": "dcb00ac27cbbcdec61d81f1df9e852ba81a2197e7804ec89cab76e44",
+    "infile_hash": "c3ce0b2b9780f27f787297f75e5477e990481b962dcee420809540e0",
     "outfile": null,
     "outfile_hash": null,
     "stdout": "asr_json-modules_02-70a491a.stdout",
-    "stdout_hash": "f01c2568a6bbb12f504e47ab4ca342362c2b277b186ea8a6d02f8ba9",
-    "stderr": null,
-    "stderr_hash": null,
+    "stdout_hash": "baae33b908a2ae0da9c7dd50b6307a768b0360e514987d70d3e37dc4",
+    "stderr": "asr_json-modules_02-70a491a.stderr",
+    "stderr_hash": "67b8bf471b878cb687ed200fe5d207b6b4acb9d1e1096a930576fba9",
     "returncode": 0
 }
diff --git a/tests/reference/asr_json-modules_02-70a491a.stderr b/tests/reference/asr_json-modules_02-70a491a.stderr
@@ -0,0 +1,14 @@
+[0;33;1mwarning[0;0m[0;1m: The symbol 'f' imported from modules_02b will shadow the existing symbol 'f'[0;0m
+ [0;34;1m-->[0;0m tests/../integration_tests/modules_02.py:1:28
+  [0;34;1m|[0;0m
+[0;34;1m1 |[0;0m from modules_02b import f, f
+  [0;34;1m|[0;0m                            [0;33;1m^ new symbol[0;0m
+
+ [0;34;1m-->[0;0m tests/../integration_tests/modules_02b.py:3:1 - 5:16
+  [0;34;1m|[0;0m
+[0;34;1m3 |[0;0m    def f():
+  [0;34;1m|[0;0m    [0;33;1m^^^^^^^^...[0;0m
+...
+  [0;34;1m|[0;0m
+[0;34;1m5 |[0;0m        print("f()")
+  [0;34;1m|[0;0m [0;33;1m...^^^^^^^^^^^^^^^^ old symbol implementation[0;0m
diff --git a/tests/reference/asr_json-modules_02-70a491a.stdout b/tests/reference/asr_json-modules_02-70a491a.stdout

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-from modules_02b import f`
	`1`	`+from modules_02b import f, f`
`2`	`2`	`from lpython import i32`
`3`	`3`
`4`	`4`	`def main0():`
-Original file line number
+Diff line change
@@ @@ -0,0 +1,14 @@ @@
 +[0;33;1mwarning[0;0m[0;1m: The symbol 'f' imported from modules_02b will shadow the existing symbol 'f'[0;0m
 + [0;34;1m-->[0;0m tests/../integration_tests/modules_02.py:1:28
 +  [0;34;1m|[0;0m
 +[0;34;1m1 |[0;0m from modules_02b import f, f
 +  [0;34;1m|[0;0m                            [0;33;1m^ new symbol[0;0m
++
 + [0;34;1m-->[0;0m tests/../integration_tests/modules_02b.py:3:1 - 5:16
 +  [0;34;1m|[0;0m
 +[0;34;1m3 |[0;0m    def f():
 +  [0;34;1m|[0;0m    [0;33;1m^^^^^^^^...[0;0m
 +...
 +  [0;34;1m|[0;0m
 +[0;34;1m5 |[0;0m        print("f()")
 +  [0;34;1m|[0;0m [0;33;1m...^^^^^^^^^^^^^^^^ old symbol implementation[0;0m