From 2eaf48d2662ae124e9f76f33dc74059c4c9a38e8 Mon Sep 17 00:00:00 2001
From: timholy <tim.holy@gmail.com>
Date: Wed, 10 Sep 2014 09:14:00 -0500
Subject: [PATCH] Add inline macro via :meta expressions

---
 base/cartesian.jl |  6 ++++++
 base/exports.jl   |  3 ++-
 base/expr.jl      | 41 +++++++++++++++++++++++++++++++++++++++++
 base/inference.jl |  7 +++----
 src/alloc.c       |  2 +-
 src/interpreter.c |  3 +++
 src/jltypes.c     |  1 +
 src/julia.h       |  2 +-
 8 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/base/cartesian.jl b/base/cartesian.jl
index 9fd9abd0ef382..4c4f6d9bc9b12 100644
--- a/base/cartesian.jl
+++ b/base/cartesian.jl
@@ -30,6 +30,9 @@ const CARTESIAN_DIMS = 4
 #   myfunction(A::AbstractArray, I::Int...N)
 # where N can be an integer or symbol. Currently T...N generates a parser error.
 macro ngenerate(itersym, returntypeexpr, funcexpr)
+    if isa(funcexpr, Expr) && funcexpr.head == :macrocall && funcexpr.args[1] == symbol("@inline")
+        funcexpr = Base._inline(funcexpr.args[2])
+    end
     isfuncexpr(funcexpr) || error("Requires a function expression")
     esc(ngenerate(itersym, returntypeexpr, funcexpr.args[1], N->sreplace!(copy(funcexpr.args[2]), itersym, N)))
 end
@@ -57,6 +60,9 @@ macro nsplat(itersym, args...)
     else
         error("Wrong number of arguments")
     end
+    if isa(funcexpr, Expr) && funcexpr.head == :macrocall && funcexpr.args[1] == symbol("@inline")
+        funcexpr = Base._inline(funcexpr.args[2])
+    end
     isfuncexpr(funcexpr) || error("Second argument must be a function expression")
     prototype = funcexpr.args[1]
     body = funcexpr.args[2]
diff --git a/base/exports.jl b/base/exports.jl
index d6bfb42a36596..d46ceecaba98c 100644
--- a/base/exports.jl
+++ b/base/exports.jl
@@ -1384,4 +1384,5 @@ export
     @inbounds,
     @simd,
     @label,
-    @goto
+    @goto,
+    @inline
diff --git a/base/expr.jl b/base/expr.jl
index f5c297ab9f468..66db044c240aa 100644
--- a/base/expr.jl
+++ b/base/expr.jl
@@ -63,6 +63,13 @@ macro eval(x)
     :($(esc(:eval))($(Expr(:quote,x))))
 end
 
+macro inline(ex)
+    esc(_inline(ex))
+end
+
+_inline(ex::Expr) = pushmeta!(ex, :inline)
+_inline(arg) = arg
+
 ## some macro utilities ##
 
 find_vars(e) = find_vars(e, {})
@@ -95,3 +102,37 @@ function localize_vars(expr, esca)
     end
     Expr(:localize, :(()->($expr)), v...)
 end
+
+function pushmeta!(ex::Expr, sym::Symbol)
+    if ex.head == :function
+        body::Expr = ex.args[2]
+        if !isempty(body.args) && isa(body.args[1], Expr) && (body.args[1]::Expr).head == :meta
+            push!((body.args[1]::Expr).args, sym)
+        else
+            unshift!(body.args, Expr(:meta, sym))
+        end
+    elseif (ex.head == :(=) && typeof(ex.args[1]) == Expr && ex.args[1].head == :call)
+        ex = Expr(:function, ex.args[1], Expr(:block, Expr(:meta, sym), ex.args[2]))
+#     else
+#         ex = Expr(:withmeta, ex, sym)
+    end
+    ex
+end
+
+function popmeta!(body::Expr, sym::Symbol)
+    if isa(body.args[1],Expr) && (body.args[1]::Expr).head === :meta
+        metaargs = (body.args[1]::Expr).args
+        for i = 1:length(metaargs)
+            if metaargs[i] == sym
+                if length(metaargs) == 1
+                    shift!(body.args)        # get rid of :meta Expr
+                else
+                    deleteat!(metaargs, i)   # delete this portion of the metadata
+                end
+                return true
+            end
+        end
+    end
+    false
+end
+popmeta!(arg, sym) = false
diff --git a/base/inference.jl b/base/inference.jl
index b589538e8c976..834d9d0d94799 100644
--- a/base/inference.jl
+++ b/base/inference.jl
@@ -2496,10 +2496,9 @@ const inline_incompletematch_allowed = false
 
 inline_worthy(body, cost::Real) = true
 function inline_worthy(body::Expr, cost::Real=1.0) # precondition: 0<cost
-#    if isa(body.args[1],QuoteNode) && (body.args[1]::QuoteNode).value === :inline
-#        shift!(body.args)
-#        return true
-#    end
+    if popmeta!(body, :inline)
+        return true
+    end
     symlim = 1+5/cost
     if length(body.args) < symlim
         symlim *= 16
diff --git a/src/alloc.c b/src/alloc.c
index fe0b02a6c2013..6a747e9a247f2 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -91,7 +91,7 @@ jl_sym_t *compositetype_sym; jl_sym_t *type_goto_sym;
 jl_sym_t *global_sym; jl_sym_t *tuple_sym;
 jl_sym_t *dot_sym;    jl_sym_t *newvar_sym;
 jl_sym_t *boundscheck_sym; jl_sym_t *copyast_sym;
-jl_sym_t *simdloop_sym;
+jl_sym_t *simdloop_sym; jl_sym_t *meta_sym;
 
 typedef struct {
     int64_t a;
diff --git a/src/interpreter.c b/src/interpreter.c
index 0d445d107e2b7..f62446357e589 100644
--- a/src/interpreter.c
+++ b/src/interpreter.c
@@ -455,6 +455,9 @@ static jl_value_t *eval(jl_value_t *e, jl_value_t **locals, size_t nl)
     else if (ex->head == simdloop_sym) {
         return (jl_value_t*)jl_nothing;
     }
+    else if (ex->head == meta_sym) {
+        return (jl_value_t*)jl_nothing;
+    }
     jl_errorf("unsupported or misplaced expression %s", ex->head->name);
     return (jl_value_t*)jl_nothing;
 }
diff --git a/src/jltypes.c b/src/jltypes.c
index 26d6226d811aa..70875ea48a72d 100644
--- a/src/jltypes.c
+++ b/src/jltypes.c
@@ -3261,6 +3261,7 @@ void jl_init_types(void)
     newvar_sym = jl_symbol("newvar");
     copyast_sym = jl_symbol("copyast");
     simdloop_sym = jl_symbol("simdloop");
+    meta_sym = jl_symbol("meta");
 }
 
 #ifdef __cplusplus
diff --git a/src/julia.h b/src/julia.h
index b95c9e91d2c1a..13a04464728a5 100644
--- a/src/julia.h
+++ b/src/julia.h
@@ -421,7 +421,7 @@ extern jl_sym_t *abstracttype_sym; extern jl_sym_t *bitstype_sym;
 extern jl_sym_t *compositetype_sym; extern jl_sym_t *type_goto_sym;
 extern jl_sym_t *global_sym;  extern jl_sym_t *tuple_sym;
 extern jl_sym_t *boundscheck_sym; extern jl_sym_t *copyast_sym;
-extern jl_sym_t *simdloop_sym;
+extern jl_sym_t *simdloop_sym; extern jl_sym_t *meta_sym;
 
 
 // object accessors -----------------------------------------------------------