From 31087f8d4bbc06e5bec44cb14cab3a922b5e4855 Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@cs.stanford.edu>
Date: Fri, 4 Sep 2020 12:54:07 +0900
Subject: [PATCH] Handle inline functions as static functions

---
 chibicc.h       |  1 +
 parse.c         | 19 ++++++++++++-------
 test/driver.sh  | 12 ++++++++++++
 test/extern.c   |  4 ++++
 test/function.c |  6 ++++++
 5 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/chibicc.h b/chibicc.h
index 8107226..ff4a99d 100644
--- a/chibicc.h
+++ b/chibicc.h
@@ -140,6 +140,7 @@ struct Obj {
   Relocation *rel;
 
   // Function
+  bool is_inline;
   Obj *params;
   Node *body;
   Obj *locals;
diff --git a/parse.c b/parse.c
index 34ebd88..53374e9 100644
--- a/parse.c
+++ b/parse.c
@@ -54,6 +54,7 @@ typedef struct {
   bool is_typedef;
   bool is_static;
   bool is_extern;
+  bool is_inline;
   int align;
 } VarAttr;
 
@@ -363,7 +364,7 @@ static void push_tag_scope(Token *tok, Type *ty) {
 }
 
 // declspec = ("void" | "_Bool" | "char" | "short" | "int" | "long"
-//             | "typedef" | "static" | "extern"
+//             | "typedef" | "static" | "extern" | "inline"
 //             | "signed" | "unsigned"
 //             | struct-decl | union-decl | typedef-name
 //             | enum-specifier | typeof-specifier
@@ -405,7 +406,8 @@ static Type *declspec(Token **rest, Token *tok, VarAttr *attr) {
 
   while (is_typename(tok)) {
     // Handle storage class specifiers.
-    if (equal(tok, "typedef") || equal(tok, "static") || equal(tok, "extern")) {
+    if (equal(tok, "typedef") || equal(tok, "static") || equal(tok, "extern") ||
+        equal(tok, "inline")) {
       if (!attr)
         error_tok(tok, "storage class specifier is not allowed in this context");
 
@@ -413,11 +415,13 @@ static Type *declspec(Token **rest, Token *tok, VarAttr *attr) {
         attr->is_typedef = true;
       else if (equal(tok, "static"))
         attr->is_static = true;
-      else
+      else if (equal(tok, "extern"))
         attr->is_extern = true;
+      else
+        attr->is_inline = true;
 
-      if (attr->is_typedef && attr->is_static + attr->is_extern > 1)
-        error_tok(tok, "typedef may not be used together with static or extern");
+      if (attr->is_typedef && attr->is_static + attr->is_extern + attr->is_inline > 1)
+        error_tok(tok, "typedef may not be used together with static, extern or inline");
       tok = tok->next;
       continue;
     }
@@ -1401,7 +1405,7 @@ static bool is_typename(Token *tok) {
     "void", "_Bool", "char", "short", "int", "long", "struct", "union",
     "typedef", "enum", "static", "extern", "_Alignas", "signed", "unsigned",
     "const", "volatile", "auto", "register", "restrict", "__restrict",
-    "__restrict__", "_Noreturn", "float", "double", "typeof",
+    "__restrict__", "_Noreturn", "float", "double", "typeof", "inline",
   };
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++)
@@ -2851,7 +2855,8 @@ static Token *function(Token *tok, Type *basety, VarAttr *attr) {
   Obj *fn = new_gvar(get_ident(ty->name), ty);
   fn->is_function = true;
   fn->is_definition = !consume(&tok, tok, ";");
-  fn->is_static = attr->is_static;
+  fn->is_static = attr->is_static || (attr->is_inline && !attr->is_extern);
+  fn->is_inline = attr->is_inline;
 
   if (!fn->is_definition)
     return tok;
diff --git a/test/driver.sh b/test/driver.sh
index d1423a4..9dadeec 100755
--- a/test/driver.sh
+++ b/test/driver.sh
@@ -113,4 +113,16 @@ check 'ignored options'
 printf '\xef\xbb\xbfxyz\n' | $chibicc -E -o- - | grep -q '^xyz'
 check 'BOM marker'
 
+# Inline functions
+echo 'inline void foo() {}' > $tmp/inline1.c
+echo 'inline void foo() {}' > $tmp/inline2.c
+echo 'int main() { return 0; }' > $tmp/inline3.c
+$chibicc -o /dev/null $tmp/inline1.c $tmp/inline2.c $tmp/inline3.c
+check inline
+
+echo 'extern inline void foo() {}' > $tmp/inline1.c
+echo 'int foo(); int main() { foo(); }' > $tmp/inline2.c
+$chibicc -o /dev/null $tmp/inline1.c $tmp/inline2.c
+check inline
+
 echo OK
diff --git a/test/extern.c b/test/extern.c
index c1e8956..4a1dac9 100644
--- a/test/extern.c
+++ b/test/extern.c
@@ -3,6 +3,10 @@
 extern int ext1;
 extern int *ext2;
 
+inline int inline_fn(void) {
+  return 3;
+}
+
 int main() {
   ASSERT(5, ext1);
   ASSERT(5, *ext2);
diff --git a/test/function.c b/test/function.c
index 0fff547..586f10c 100644
--- a/test/function.c
+++ b/test/function.c
@@ -197,6 +197,10 @@ Ty21 struct_test38(void) {
   return (Ty21){1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20};
 }
 
+inline int inline_fn(void) {
+  return 3;
+}
+
 int main() {
   ASSERT(3, ret3());
   ASSERT(8, add2(3, 5));
@@ -365,5 +369,7 @@ int main() {
 
   ASSERT(5, (***add2)(2,3));
 
+  ASSERT(3, inline_fn());
+
   printf("OK\n");
 }