feat(preprocessor): add file-local conditional switches

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

11 files changed, 130 insertions, 0 deletions

diff --git a/tests/i/preprocessor/case.json b/tests/i/preprocessor/case.json
new file mode 100644
index 0000000..c66d109
--- /dev/null
+++ b/tests/i/preprocessor/case.json
@@ -0,0 +1,6 @@
+{
+  "sources": [
+    "program.cps",
+    "peer.cps"
+  ]
+}
diff --git a/tests/i/preprocessor/expected.txt b/tests/i/preprocessor/expected.txt
new file mode 100644
index 0000000..d537856
--- /dev/null
+++ b/tests/i/preprocessor/expected.txt
@@ -0,0 +1,8 @@
+1
+2
+3
+4
+5
+6
+7
+PP_DEFINE Quoted
diff --git a/tests/i/preprocessor/notes.md b/tests/i/preprocessor/notes.md
new file mode 100644
index 0000000..2afe007
--- /dev/null
+++ b/tests/i/preprocessor/notes.md
@@ -0,0 +1,5 @@
+# Trace notes
+
+Review status: pending human review.
+
+The main file enables MainFlag, independently checks lowercase mainflag, and skips a disabled nested region containing invalid source and switch changes. Hidden remains undefined and MainFlag remains defined until explicitly removed. A switch named Flag does not replace the ordinary variable. Neither input sees the other's switches. Enabled branches print 1 through 7, followed by a literal containing a directive name. These are compiler extensions.
diff --git a/tests/i/preprocessor/peer.cps b/tests/i/preprocessor/peer.cps
new file mode 100644
index 0000000..bb745c3
--- /dev/null
+++ b/tests/i/preprocessor/peer.cps
@@ -0,0 +1,9 @@
+PP_DEFINE PeerFlag
+PROCEDURE Peer()
+PP_IFDEF MainFlag
+OUTPUT MissingMainFlag
+PP_ENDIF
+PP_IFDEF PeerFlag
+OUTPUT 7
+PP_ENDIF
+ENDPROCEDURE
diff --git a/tests/i/preprocessor/program.cps b/tests/i/preprocessor/program.cps
new file mode 100644
index 0000000..fe0b9ce
--- /dev/null
+++ b/tests/i/preprocessor/program.cps
@@ -0,0 +1,44 @@
+PP_DEFINE MainFlag // File-local and case-sensitive.
+PP_DEFINE MainFlag
+INCLUDE "peer.cps"
+PP_IFDEF MainFlag
+OUTPUT 1
+PP_ENDIF
+PP_IFNDEF mainflag
+OUTPUT 2
+PP_ENDIF
+PP_IFDEF PeerFlag
+OUTPUT MissingPeerFlag
+PP_ENDIF
+PP_IFDEF Absent
+"unterminated literal
+PP_DEFINE Hidden
+PP_UNDEF MainFlag
+PP_IFNDEF Other
+#INVALID
+PP_DEFINE
+PP_ENDIF
+PP_ENDIF
+PP_IFNDEF Hidden
+OUTPUT 3
+PP_ENDIF
+PP_IFDEF MainFlag
+OUTPUT 4
+PP_ENDIF
+PP_UNDEF MainFlag
+PP_UNDEF MainFlag
+PP_IFDEF MainFlag
+OUTPUT MissingMainFlag
+PP_ENDIF
+PP_IFNDEF MainFlag
+    PP_IFNDEF Hidden // Nested enabled conditions.
+OUTPUT 5
+    PP_ENDIF
+PP_ENDIF
+DECLARE Flag : INTEGER
+PP_DEFINE Flag
+Flag <- 6
+OUTPUT Flag
+CALL Peer()
+// PP_IFDEF CommentedOut
+OUTPUT "PP_DEFINE Quoted"
diff --git a/tests/iii/preprocessor-directives/case.json b/tests/iii/preprocessor-directives/case.json
new file mode 100644
index 0000000..cc0301b
--- /dev/null
+++ b/tests/iii/preprocessor-directives/case.json
@@ -0,0 +1,28 @@
+{
+  "errors": [
+    {
+      "reason": "PP_ENDIF without matching",
+      "line": 1
+    },
+    {
+      "reason": "PP_DEFINE requires exactly one switch name",
+      "line": 2
+    },
+    {
+      "reason": "PP_UNDEF requires exactly one switch name",
+      "line": 3
+    },
+    {
+      "reason": "PP_IFDEF requires exactly one switch name",
+      "line": 4
+    },
+    {
+      "reason": "PP_ENDIF does not take arguments",
+      "line": 5
+    },
+    {
+      "reason": "Unterminated preprocessor conditional.*PP_ENDIF",
+      "line": 6
+    }
+  ]
+}
diff --git a/tests/iii/preprocessor-directives/program.cps b/tests/iii/preprocessor-directives/program.cps
new file mode 100644
index 0000000..8b9bee6
--- /dev/null
+++ b/tests/iii/preprocessor-directives/program.cps
@@ -0,0 +1,6 @@
+PP_ENDIF
+PP_DEFINE
+PP_UNDEF Flag extra
+PP_IFDEF 123
+PP_ENDIF extra
+PP_IFNDEF Open
diff --git a/tests/iii/preprocessor-lines/case.json b/tests/iii/preprocessor-lines/case.json
new file mode 100644
index 0000000..c84bc94
--- /dev/null
+++ b/tests/iii/preprocessor-lines/case.json
@@ -0,0 +1,8 @@
+{
+  "errors": [
+    {
+      "reason": "Unknown variable name Unknown",
+      "line": 7
+    }
+  ]
+}
diff --git a/tests/iii/preprocessor-lines/program.cps b/tests/iii/preprocessor-lines/program.cps
new file mode 100644
index 0000000..5b21eaf
--- /dev/null
+++ b/tests/iii/preprocessor-lines/program.cps
@@ -0,0 +1,7 @@
+PP_IFDEF Missing
+"invalid skipped literal
+PP_IFNDEF Nested
+OUTPUT Unknown
+PP_ENDIF
+PP_ENDIF
+OUTPUT Unknown
diff --git a/tests/iii/preprocessor-reserved/case.json b/tests/iii/preprocessor-reserved/case.json
new file mode 100644
index 0000000..e4d76fa
--- /dev/null
+++ b/tests/iii/preprocessor-reserved/case.json
@@ -0,0 +1,8 @@
+{
+  "errors": [
+    {
+      "reason": "Expected identifier after DECLARE",
+      "line": 1
+    }
+  ]
+}
diff --git a/tests/iii/preprocessor-reserved/program.cps b/tests/iii/preprocessor-reserved/program.cps
new file mode 100644
index 0000000..be20fb2
--- /dev/null
+++ b/tests/iii/preprocessor-reserved/program.cps
@@ -0,0 +1 @@
+DECLARE PP_DEFINE : INTEGER