From 92caea8c0e61ec01346e512eccc44723c82f1d2b Mon Sep 17 00:00:00 2001
From: Melody Horn <melody@boringcactus.com>
Date: Fri, 26 Mar 2021 20:38:17 -0600
Subject: implement builtins in the worst imaginable way

---
 src/args.rs         |   4 --
 src/makefile/mod.rs | 123 +++++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 117 insertions(+), 10 deletions(-)

diff --git a/src/args.rs b/src/args.rs
index babd7a0..41ff4f0 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -130,10 +130,6 @@ impl Args {
             .chain(env_makeflags.into_iter())
             .chain(args);
 
-        let args = args.collect::<Vec<_>>();
-        dbg!(&args);
-        let args = args.into_iter();
-
         Args::from_iter(args)
     }
 
diff --git a/src/makefile/mod.rs b/src/makefile/mod.rs
index e8adac9..2959953 100644
--- a/src/makefile/mod.rs
+++ b/src/makefile/mod.rs
@@ -17,7 +17,7 @@ mod token;
 
 use token::{tokenize, Token, TokenString};
 
-#[derive(PartialEq, Eq, Clone)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 pub struct InferenceRule {
     /// POSIX calls this ".s1" but that's not useful.
     product: String,
@@ -104,7 +104,7 @@ impl fmt::Display for Target {
     }
 }
 
-#[derive(PartialEq, Eq, Clone)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 pub struct CommandLine {
     /// If the command prefix contains a <hyphen-minus>, or the -i option is present, or
     /// the special target .IGNORE has either the current target as a prerequisite or has
@@ -204,7 +204,7 @@ impl fmt::Display for CommandLine {
         }
         let execution_line = format!("{}", &self.execution_line);
         let execution_line = execution_line.replace("\n", "↵\n");
-        writeln!(f, "{}", execution_line)?;
+        write!(f, "{}", execution_line)?;
         Ok(())
     }
 }
@@ -727,11 +727,122 @@ impl fmt::Display for Makefile {
 }
 
 fn builtin_inference_rules() -> Vec<InferenceRule> {
-    todo!()
+    // This is a terrible idea.
+    macro_rules! prepend_dot {
+        ($x:tt) => {concat!(".", stringify!($x))};
+        () => {""};
+    }
+
+    macro_rules! make {
+        {$(.$first:tt$(.$second:tt)?:
+            $($cmd:literal)+)+} => {
+            vec![$(
+                InferenceRule {
+                    product: prepend_dot!($($second)?).into(),
+                    prereq: concat!(".", stringify!($first)).into(),
+                    commands: vec![$(CommandLine::from($cmd.parse().unwrap())),+],
+                }
+            ),+]
+        };
+    }
+
+    make! {
+        .c:
+            "$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<"
+        .f:
+            "$(FC) $(FFLAGS) $(LDFLAGS) -o $@ $<"
+        .sh:
+            "cp $< $@"
+            "chmod a+x $@"
+
+        .c.o:
+            "$(CC) $(CFLAGS) -c $<"
+        .f.o:
+            "$(FC) $(FFLAGS) -c $<"
+        .y.o:
+            "$(YACC) $(YFLAGS) $<"
+            "$(CC) $(CFLAGS) -c y.tab.c"
+            "rm -f y.tab.c"
+            "mv y.tab.o $@"
+        .l.o:
+            "$(LEX) $(LFLAGS) $<"
+            "$(CC) $(CFLAGS) -c lex.yy.c"
+            "rm -f lex.yy.c"
+            "mv lex.yy.o $@"
+        .y.c:
+            "$(YACC) $(YFLAGS) $<"
+            "mv y.tab.c $@"
+        .l.c:
+            "$(LEX) $(LFLAGS) $<"
+            "mv lex.yy.c $@"
+        .c.a:
+            "$(CC) -c $(CFLAGS) $<"
+            "$(AR) $(ARFLAGS) $@ $*.o"
+            "rm -f $*.o"
+        .f.a:
+            "$(FC) -c $(FFLAGS) $<"
+            "$(AR) $(ARFLAGS) $@ $*.o"
+            "rm -f $*.o"
+    }
 }
 fn builtin_macros() -> Vec<(&'static str, TokenString)> {
-    todo!()
+    // Fuck it, might as well.
+    macro_rules! handle {
+        ($value:ident) => {stringify!($value)};
+        ($value:literal) => {$value};
+    }
+    macro_rules! make {
+        ($($name:ident=$value:tt)+) => {vec![$(
+            (stringify!($name), handle!($value).parse().unwrap())
+        ),+]};
+    }
+
+    make![
+        MAKE=makers
+        AR=ar
+        YACC=yacc
+        YFLAGS=""
+        LEX=lex
+        LFLAGS=""
+        LDFLAGS=""
+
+        AS=as
+        CC=cc
+        CXX="g++"
+        CPP="$(CC) -E"
+        FC=f77
+        PC=pc
+        CO=co
+        GET=get
+        LINT=lint
+        MAKEINFO=makeinfo
+        TEX=tex
+        TEXI2DVI=texi2dvi
+        WEAVE=weave
+        CWEAVE=cweave
+        TANGLE=tangle
+        CTANGLE=ctangle
+        RM="rm -f"
+
+        ARFLAGS="rv"
+        CFLAGS=""
+        FFLAGS=""
+    ]
 }
 fn builtin_targets() -> Vec<Target> {
-    todo!()
+    // even i'm not going to do that just for this
+    vec![
+        Target {
+            name: ".SUFFIXES".into(),
+            prerequisites: vec![".o", ".c", ".y", ".l", ".a", ".sh", ".f"].into_iter().map(String::from).collect(),
+            commands: vec![],
+            already_updated: Cell::new(false),
+        }
+    ]
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
 }
-- 
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