Support for __LINE__ and __FILE__ in preprocessor (#1772)

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

* First pass support for __LINE__ and __FILE__.

* Test include handling with __FILE__
Fix diagnostic compare when input is empty.

* Fix some issues in preprocessor handling of special macros like __LINE__
Add a more complex test.

* Use CONCAT2 in tests, because preprocessor doesn't quite get parameter expansion correct.

* Make __FILE__ and __LINE__ behave more like Clang/Gcc.

* A test for preprocessor bug.

* Fix __LINE__ and __FILE__ in macro expansion, should be initiating location.

* Fix some comments.

* Small tidy up around builtin macros.

* Small improvements for macro type names.
Escape found paths.

15 files changed, 156 insertions, 0 deletions

diff --git a/tests/preprocessor/include/special-macro-include.h b/tests/preprocessor/include/special-macro-include.h
new file mode 100644
index 000000000..f2aa20951
--- /dev/null
+++ b/tests/preprocessor/include/special-macro-include.h
@@ -0,0 +1,5 @@
+// special-macro-include.h
+
+// Used by the `special-macro-include.slang` test
+
+__FILE__ __LINE__
\ No newline at end of file
diff --git a/tests/preprocessor/paste-non-expansion.slang b/tests/preprocessor/paste-non-expansion.slang
new file mode 100644
index 000000000..8270db676
--- /dev/null
+++ b/tests/preprocessor/paste-non-expansion.slang
@@ -0,0 +1,16 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+// NOTE! This test should *fail*, if preprocessor is working correctly!
+
+// This demonstrates the existance of a bug in Slang preprocessor macro expansion. Could be due to incorrect paste handling
+// or perhaps the rules around parameter expansion.
+
+#define CONCAT2(x, y) x ## y
+#define CONCAT(x, y) CONCAT2(x, y)
+
+#define SOMETHING someThing
+
+// Should be someThingElse
+CONCAT(SOMETHING, Else)
+// Should be SOMETHINGAnother, but Slang expands to produce someThingAnother
+CONCAT2(SOMETHING, Another)
\ No newline at end of file
diff --git a/tests/preprocessor/paste-non-expansion.slang.expected b/tests/preprocessor/paste-non-expansion.slang.expected
new file mode 100644
index 000000000..2fbb7bad3
--- /dev/null
+++ b/tests/preprocessor/paste-non-expansion.slang.expected
@@ -0,0 +1,6 @@
+result code = 0
+standard error = {
+}
+standard output = {
+someThingElse someThingAnother 
+}
diff --git a/tests/preprocessor/special-macro-complex.slang b/tests/preprocessor/special-macro-complex.slang
new file mode 100644
index 000000000..a2ea962e1
--- /dev/null
+++ b/tests/preprocessor/special-macro-complex.slang
@@ -0,0 +1,37 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+// Testing of handling of __LINE__ in macros
+// Pasting, and some other aspects.
+
+
+// Lets try some macro pasting. NOTE strictly speaking we need CONCAT2 (as tested on other compilers, but Slang does not indicating a preprocessor bug!)
+#define CONCAT2(x, y) x ## y
+#define CONCAT(x, y) CONCAT2(x, y)
+
+CONCAT(Thing, __LINE__)
+
+// Lets see if works okay in conditionals
+
+#if __LINE__ == 15
+Yeppers
+#else
+Nopers
+#endif
+
+// Lets try a paste in a conditional
+#if CONCAT(__LINE__, __LINE__) == 2222
+PasteConditional
+#endif
+
+// Lets check that we pick up the nominal line
+#line 10
+__LINE__
+
+// Reset the line numbering
+#line default
+
+// __LINE__ number will be for the macro invocation, not the expansion
+
+#define SOMEMACRO __LINE__
+
+SOMEMACRO
\ No newline at end of file
diff --git a/tests/preprocessor/special-macro-complex.slang.expected b/tests/preprocessor/special-macro-complex.slang.expected
new file mode 100644
index 000000000..542fd320d
--- /dev/null
+++ b/tests/preprocessor/special-macro-complex.slang.expected
@@ -0,0 +1,6 @@
+result code = 0
+standard error = {
+}
+standard output = {
+Thing11 Yeppers PasteConditional 10 37 
+}
diff --git a/tests/preprocessor/special-macro-include.slang b/tests/preprocessor/special-macro-include.slang
new file mode 100644
index 000000000..79aa8b566
--- /dev/null
+++ b/tests/preprocessor/special-macro-include.slang
@@ -0,0 +1,4 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+#include "./include/special-macro-include.h"
+#include "include/special-macro-include.h"
\ No newline at end of file
diff --git a/tests/preprocessor/special-macro-include.slang.expected b/tests/preprocessor/special-macro-include.slang.expected
new file mode 100644
index 000000000..f95c8303a
--- /dev/null
+++ b/tests/preprocessor/special-macro-include.slang.expected
@@ -0,0 +1,6 @@
+result code = 0
+standard error = {
+}
+standard output = {
+"tests/preprocessor/include/special-macro-include.h" 5 "tests/preprocessor/include/special-macro-include.h" 5 
+}
diff --git a/tests/preprocessor/special-macro-multi-line.slang b/tests/preprocessor/special-macro-multi-line.slang
new file mode 100644
index 000000000..b8d12d601
--- /dev/null
+++ b/tests/preprocessor/special-macro-multi-line.slang
@@ -0,0 +1,12 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+// Output here varies by compiler. Gcc makes the line the one with M. Clang makes it the end bracket.
+
+#define M(ARG) __LINE__
+
+
+int x = M
+(
+ignored
+)
+;
diff --git a/tests/preprocessor/special-macro-multi-line.slang.expected b/tests/preprocessor/special-macro-multi-line.slang.expected
new file mode 100644
index 000000000..984ce94f5
--- /dev/null
+++ b/tests/preprocessor/special-macro-multi-line.slang.expected
@@ -0,0 +1,6 @@
+result code = 0
+standard error = {
+}
+standard output = {
+int x = 8 ; 
+}
diff --git a/tests/preprocessor/special-macro-redefine-function.slang b/tests/preprocessor/special-macro-redefine-function.slang
new file mode 100644
index 000000000..cca38f39f
--- /dev/null
+++ b/tests/preprocessor/special-macro-redefine-function.slang
@@ -0,0 +1,14 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+// 
+// Check replacing __FILE__
+// 
+
+#define __FILE__(x) "Is" x
+
+__FILE__("Anybody")
+__FILE__(There)
+
+#undef __FILE__
+
+__FILE__
\ No newline at end of file
diff --git a/tests/preprocessor/special-macro-redefine-function.slang.expected b/tests/preprocessor/special-macro-redefine-function.slang.expected
new file mode 100644
index 000000000..923335509
--- /dev/null
+++ b/tests/preprocessor/special-macro-redefine-function.slang.expected
@@ -0,0 +1,9 @@
+result code = 0
+standard error = {
+tests/preprocessor/special-macro-redefine-function.slang(7): warning 15404: Redefinition of builtin macro '__FILE__'
+#define __FILE__(x) "Is" x
+        ^~~~~~~~
+}
+standard output = {
+"Is" "Anybody" "Is" There __FILE__ 
+}
diff --git a/tests/preprocessor/special-macro-redefine-object.slang b/tests/preprocessor/special-macro-redefine-object.slang
new file mode 100644
index 000000000..531d56ae7
--- /dev/null
+++ b/tests/preprocessor/special-macro-redefine-object.slang
@@ -0,0 +1,13 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+// 
+// Check replacing __LINE__
+// 
+
+#define __LINE__ "Hello"
+
+__LINE__
+
+#undef __LINE__
+
+__LINE__
diff --git a/tests/preprocessor/special-macro-redefine-object.slang.expected b/tests/preprocessor/special-macro-redefine-object.slang.expected
new file mode 100644
index 000000000..ed5fbb16e
--- /dev/null
+++ b/tests/preprocessor/special-macro-redefine-object.slang.expected
@@ -0,0 +1,9 @@
+result code = 0
+standard error = {
+tests/preprocessor/special-macro-redefine-object.slang(7): warning 15404: Redefinition of builtin macro '__LINE__'
+#define __LINE__ "Hello"
+        ^~~~~~~~
+}
+standard output = {
+"Hello" __LINE__ 
+}
diff --git a/tests/preprocessor/special-macro-simple.slang b/tests/preprocessor/special-macro-simple.slang
new file mode 100644
index 000000000..e6e823475
--- /dev/null
+++ b/tests/preprocessor/special-macro-simple.slang
@@ -0,0 +1,7 @@
+//DIAGNOSTIC_TEST:SIMPLE:-E
+
+//__LINE__ and __FILE__ support
+
+__LINE__
+
+__FILE__
diff --git a/tests/preprocessor/special-macro-simple.slang.expected b/tests/preprocessor/special-macro-simple.slang.expected
new file mode 100644
index 000000000..6d8b5212d
--- /dev/null
+++ b/tests/preprocessor/special-macro-simple.slang.expected
@@ -0,0 +1,6 @@
+result code = 0
+standard error = {
+}
+standard output = {
+5 "tests/preprocessor/special-macro-simple.slang" 
+}