Detect duplicate labels (#774)

* fix: detect duplicate labels in a single section

* wip: wip

* wip: wip

* test: fix tests for duplicate labels

* wip: wip

* fix: improve cb_validate_labels

Author: yutaro-sakamoto

cobj/cobj.c

@@ -1779,6 +1779,14 @@ static int process_translate(struct filename *fn) {
   if (ret) {
     return ret;
   }
+
+  /* Validate duplicate labels in the same section */
+  for (q = current_program; q; q = q->next_program) {
+    if (cb_validate_labels(q)) {
+      return -1;
+    }
+  }
+
   if (cb_flag_syntax_only || current_program->entry_list == NULL) {
     return 0;
   }

cobj/tree.h

@@ -1500,6 +1500,7 @@ extern void cb_validate_program_environment(struct cb_program *prog);
 extern void cb_validate_program_data(struct cb_program *prog);
 extern void cb_validate_program_body(struct cb_program *prog);
 extern void cb_validate_indexed_file_key(const struct cb_file *f);
+extern int cb_validate_labels(struct cb_program *prog);
 
 extern cb_tree cb_build_expr(cb_tree list);
 extern cb_tree cb_build_cond(cb_tree x);

cobj/typeck.c

@@ -1483,6 +1483,51 @@ void cb_validate_program_body(struct cb_program *prog) {
   }
 }
 
+int cb_validate_labels(struct cb_program *prog) {
+  cb_tree l1, l2;
+  int duplicate_count = 0;
+
+  for (l1 = prog->exec_list; l1; l1 = CB_CHAIN(l1)) {
+    cb_tree x1 = CB_VALUE(l1);
+    if (!CB_LABEL_P(x1)) {
+      continue;
+    }
+    struct cb_label *label1 = CB_LABEL(x1);
+    if (label1->is_section) {
+      continue;
+    }
+
+    for (l2 = CB_CHAIN(l1); l2; l2 = CB_CHAIN(l2)) {
+      cb_tree x2 = CB_VALUE(l2);
+      if (!CB_LABEL_P(x2)) {
+        continue;
+      }
+      struct cb_label *label2 = CB_LABEL(x2);
+      if (label2->is_section) {
+        break;
+      }
+
+      if (label1->section != label2->section) {
+        break;
+      }
+
+      if (strcmp((const char *)label1->name, (const char *)label2->name) == 0) {
+        if (!label2->section || !label2->section->name ||
+            strcmp((char *)label2->section->name, "MAIN SECTION") == 0) {
+          cb_error_x(x2, _("Duplicate paragraph '%s' in the default section"),
+                     label2->name);
+        } else {
+          cb_error_x(x2, _("Duplicate paragraph '%s' in section '%s'"),
+                     label2->name, label2->section->name);
+        }
+        cb_error_x(x1, _("'%s' previously defined here"), label1->name);
+        duplicate_count++;
+      }
+    }
+  }
+  return duplicate_count;
+}
+
 /*
  * Expressions
  */

tests/syntax.src/definition.at

@@ -501,24 +501,85 @@ AT_CLEANUP
 
 AT_SETUP([Redefinition of paragraph names])
 
-AT_DATA([prog.cob], [
+AT_DATA([prog1.cob], [
        IDENTIFICATION   DIVISION.
-       PROGRAM-ID.      prog.
+       PROGRAM-ID.      prog1.
        PROCEDURE        DIVISION.
+      *No Label
        L.
+      *No Label
        L.
            STOP RUN.
 ])
 
-AT_CHECK([${COMPILE_ONLY} prog.cob], [0], ,
-[])
-
-## Change when we DON'T allow this
-## AT_CHECK([${COMPILE_ONLY} prog.cob], [1], ,
-## [prog.cob: In paragraph 'L':
-## prog.cob:6: Error: redefinition of 'L'
-## prog.cob:5: Error: 'L' previously defined here
-## ])
+AT_DATA([prog2.cob], [
+       IDENTIFICATION   DIVISION.
+       PROGRAM-ID.      prog2.
+       PROCEDURE        DIVISION.
+       SECTION-A SECTION.
+       L.
+      *No Label
+       L.
+           STOP RUN.
+])
+
+AT_DATA([prog3.cob], [
+       IDENTIFICATION   DIVISION.
+       PROGRAM-ID.      prog3.
+       PROCEDURE        DIVISION.
+       SECTION-A SECTION.
+       L.
+       SECTION-B SECTION.
+       L.
+           STOP RUN.
+])
+
+AT_CHECK([${COMPILE} -fsyntax-only prog1.cob], [1], ,
+[prog1.cob:8: Error: Duplicate paragraph 'L' in the default section
+prog1.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} -fsyntax-only prog2.cob], [1], ,
+[prog2.cob:8: Error: Duplicate paragraph 'L' in section 'SECTION-A'
+prog2.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} -fsyntax-only prog3.cob])
+
+AT_CHECK([${COMPILE} prog1.cob], [1], ,
+[prog1.cob:8: Error: Duplicate paragraph 'L' in the default section
+prog1.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} prog2.cob], [1], ,
+[prog2.cob:8: Error: Duplicate paragraph 'L' in section 'SECTION-A'
+prog2.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} prog3.cob])
+
+AT_CHECK([${COMPILE} prog1.cob prog3.cob], [1], ,
+[prog1.cob:8: Error: Duplicate paragraph 'L' in the default section
+prog1.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} prog2.cob prog3.cob], [1], ,
+[prog2.cob:8: Error: Duplicate paragraph 'L' in section 'SECTION-A'
+prog2.cob:6: Error: 'L' previously defined here
+])
+
+AT_CHECK([${COMPILE} prog3.cob prog1.cob], [1], ,
+[prog1.cob:8: Error: Duplicate paragraph 'L' in the default section
+prog1.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} prog3.cob prog2.cob], [1], ,
+[prog2.cob:8: Error: Duplicate paragraph 'L' in section 'SECTION-A'
+prog2.cob:6: Error: 'L' previously defined here
+])
+
+AT_CHECK([${COMPILE} prog1.cob prog2.cob], [1], ,
+[prog1.cob:8: Error: Duplicate paragraph 'L' in the default section
+prog1.cob:6: Error: 'L' previously defined here
+])
+AT_CHECK([${COMPILE} prog2.cob prog1.cob], [1], ,
+[prog2.cob:8: Error: Duplicate paragraph 'L' in section 'SECTION-A'
+prog2.cob:6: Error: 'L' previously defined here
+])
 
 AT_CLEANUP