Infinite generic parsing bug fix (#1799)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Fix bug causing infinite loop in parser.

* Add a faster path for LookAheadToken when the offset is 0.

* Fix typo introduced in last commit.

2 files changed, 23 insertions, 0 deletions

diff --git a/tests/bugs/eroneous-generic-parse.slang b/tests/bugs/eroneous-generic-parse.slang
new file mode 100644
index 000000000..80a693456
--- /dev/null
+++ b/tests/bugs/eroneous-generic-parse.slang
@@ -0,0 +1,15 @@
+//DIAGNOSTIC_TEST:SIMPLE: -target hlsl -entry computeMain -stage compute
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0], stride=16):out
+RWStructuredBuffer<int> outputBuffer;
+
+// Previously this definition would lead to an infinite loop in parsing.
+int doThing<1>() { return 2; }
+
+[numthreads(4, 4, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int index = dispatchThreadID.x;
+   
+    outputBuffer[index] = index;
+}
\ No newline at end of file
diff --git a/tests/bugs/eroneous-generic-parse.slang.expected b/tests/bugs/eroneous-generic-parse.slang.expected
new file mode 100644
index 000000000..a6ee73d88
--- /dev/null
+++ b/tests/bugs/eroneous-generic-parse.slang.expected
@@ -0,0 +1,8 @@
+result code = -1
+standard error = {
+tests/bugs/eroneous-generic-parse.slang(7): error 20001: unexpected integer literal, expected identifier
+int doThing<1>() { return 2; }
+            ^
+}
+standard output = {
+}