Fix #21: Allow including absolute files.

2 files changed, 44 insertions, 0 deletions

diff --git a/src/main/java/org/anarres/cpp/Preprocessor.java b/src/main/java/org/anarres/cpp/Preprocessor.java
index 8b1ddcc..5dacc91 100644
--- a/src/main/java/org/anarres/cpp/Preprocessor.java
+++ b/src/main/java/org/anarres/cpp/Preprocessor.java
@@ -1150,6 +1150,16 @@ public class Preprocessor implements Closeable {
             @Nonnull String name, boolean quoted, boolean next)
             throws IOException,
             LexerException {
+        if (name.startsWith("/")) {
+            VirtualFile file = filesystem.getFile(name);
+            if (include(file))
+                return;
+            StringBuilder buf = new StringBuilder();
+            buf.append("File not found: ").append(name);
+            error(line, 0, buf.toString());
+            return;
+        }
+
         VirtualFile pdir = null;
         if (quoted) {
             if (parent != null) {
diff --git a/src/test/java/org/anarres/cpp/IncludeAbsoluteTest.java b/src/test/java/org/anarres/cpp/IncludeAbsoluteTest.java
new file mode 100644
index 0000000..1a20a70
--- /dev/null
+++ b/src/test/java/org/anarres/cpp/IncludeAbsoluteTest.java
@@ -0,0 +1,34 @@
+package org.anarres.cpp;
+
+import java.io.BufferedReader;
+import java.io.Reader;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ *
+ * @author shevek
+ */
+public class IncludeAbsoluteTest {
+
+    private static final Logger LOG = LoggerFactory.getLogger(IncludeAbsoluteTest.class);
+
+    // TODO: Rewrite this test to get the CWD and read a file with known content in the test suite.
+    // Guava (available in test suite) can map a URL to a File resource.
+    @Test
+    public void testAbsoluteInclude() throws Exception {
+        Preprocessor pp = new Preprocessor();
+        pp.getSystemIncludePath().add("/usr/include");
+        pp.addInput(new StringLexerSource(
+                "#include </usr/include/features.h>\n"
+                + "", true));
+        Reader r = new CppReader(pp);
+        // This will error if the file isn't found.
+        BufferedReader br = new BufferedReader(r);
+        for (int i = 0; i < 10; i++) {
+            LOG.info(br.readLine());
+        }
+        br.close();
+    }
+}