add basic error handler function to validate approach (#257)

* add basic error handler function to validate approach * do not print backtrace but save in registry * bump lua version and fix travis setup so test suite can find titan runtime library * abstract throwing of errors by titan code to generator function instead of directly using luaL_error * reserve first stack slot for error value
titan-lang · Jan 29, 2019 · 11a2109 · 11a2109
1 parent cc0647a
commit 11a2109
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diff --git a/.gitignore b/.gitignore
@@ -5,4 +5,4 @@
 # lua
 lua/src/lua
 lua/src/luac
-lua-5.3.4
+lua-5.3.5
diff --git a/.travis.yml b/.travis.yml
@@ -7,20 +7,22 @@ matrix:
         - INSTALL_LUA="lua=5.3"
         - LUA="lua"
         - LUA_OS="linux"
-#    - os: osx
-#      language: generic
-#      env:
-#        - INSTALL_LUA="lua=5.3"
-#        - LUA="lua"
-#        - LUA_OS="macosx"
+    - os: osx
+      language: generic
+      env:
+        - INSTALL_LUA="lua=5.3"
+        - LUA="lua"
+        - LUA_OS="macosx"
 
 before_install:
   - if [ ! -f lua_install/bin/luarocks ]; then pip2 install hererocks; fi
   - if [ ! -f lua_install/bin/luarocks ]; then hererocks lua_install -r^ --$INSTALL_LUA; fi
   - export PATH=$PATH:$PWD/lua_install/bin # Add directory with all installed binaries to PATH
-  - wget http://www.lua.org/ftp/lua-5.3.4.tar.gz
-  - tar zxvf lua-5.3.4.tar.gz
-  - cd lua-5.3.4; make $LUA_OS MYCFLAGS=-fPIC; cd ..
+  - export LUA_PATH="./?.lua;$PWD/lua_install/share/lua/5.3/?.lua"
+  - export LUA_CPATH="./?.so;$PWD/lua_install/lib/lua/5.3/?.so"
+  - wget http://www.lua.org/ftp/lua-5.3.5.tar.gz
+  - tar zxvf lua-5.3.5.tar.gz
+  - cd lua-5.3.5; make $LUA_OS MYCFLAGS=-fPIC; cd ..
 
 install:
   - if [ ! -f lua_install/bin/busted ]; then luarocks install busted; fi

diff --git a/README.md b/README.md
@@ -8,9 +8,9 @@ application programming language with a focus on performance.
 
 # Install
 
-First you need to download, extract and build the [sources to Lua 5.3.4](http://www.lua.org/ftp/lua-5.3.4.tar.gz)
+First you need to download, extract and build the [sources to Lua 5.3.5](http://www.lua.org/ftp/lua-5.3.5.tar.gz)
 inside the folder where you cloned this repository. The Lua tarball will extract
-to a `lua-5.3.4` folder. Enter it and build Lua with `make linux MYCFLAGS=-fPIC`.
+to a `lua-5.3.5` folder. Enter it and build Lua with `make linux MYCFLAGS=-fPIC`.
 
 You can install the Titan compiler itself using  [LuaRocks](http://luarocks.org)
 this will also install all dependencies automatically.
@@ -76,7 +76,7 @@ You may need to adapt the invocation of `make` above to your platform.
 # Compiler options
 
         --print-ast                     Print the AST.
-        --lua <path>                    Path to the Lua sources (default 'lua-5.3.4/src')
+        --lua <path>                    Path to the Lua sources (default 'lua-5.3.5/src')
         --tree <path>                   Path to the source tree for your Titan modules (default '.')
         -h, --help                      Show this help message and exit.
         

diff --git a/examples/artisanal.titan b/examples/artisanal.titan
@@ -178,3 +178,16 @@ end
 function setindent(a: string)
   tab.indent = a
 end
+
+function fa(): integer
+  return fb()[1]
+end
+
+function fb(): {integer}
+  return {fc()}
+end
+
+function fc(): integer
+  local x: value = "foo"
+  return x
+end
diff --git a/spec/coder_spec.lua b/spec/coder_spec.lua
@@ -51,7 +51,7 @@ local function generate_modules(modules, main, forapp)
 end
 
 local function call(modname, code)
-    local cmd = string.format("lua-5.3.4/src/lua -l %s -e \"print(pcall(function () %s end))\"",
+    local cmd = string.format("lua-5.3.5/src/lua -l %s -e \"print(pcall(function () %s end))\"",
         modname, code)
     local f = io.popen(cmd)
     local out = f:read()
@@ -2047,6 +2047,19 @@ describe("Titan code generator", function()
         end)
     end
 
+    it("check that backtrace is being set on error", function ()
+        run_coder([[
+            function wrong(): integer
+                local x: value = {}
+                return x
+            end
+        ]], [[
+            local titan = require 'titan'
+            local ok, err = pcall(test.wrong)
+            assert(not ok)
+            assert(titan.backtrace():find(err, 1, true))
+        ]])
+    end)
 
     describe("Lua vs C operator semantics", function()
         it("unary (-)", function()

diff --git a/titan-compiler/coder.lua b/titan-compiler/coder.lua
@@ -162,6 +162,15 @@ end
 
 local checkandset
 
+local function codethrow(ctx, template, params)
+    return render([[
+        luaL_error(L, "$TEMPLATE", $PARAMS);
+    ]], {
+        TEMPLATE = template,
+        PARAMS = table.concat(params, ',')
+    }, true)
+end
+
 local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:string]], loc --[[:table]])
     local tag
     if typ._tag == "Type.Integer" then
@@ -172,19 +181,21 @@ local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:s
                 float _v = fltvalue($EXP);
                 float _flt = l_floor(_v);
                 if (TITAN_UNLIKELY(_v != _flt)) {
-                    luaL_error(L, "%s:%d:%d: type error, number '%f' has no integer representation", $FILE, $LINE, $COL, _v);
+                    $THROWFLOAT
                 } else {
                     lua_numbertointeger(_flt, &$VAR);
                 }
             } else {
-                luaL_error(L, "%s:%d:%d: type error, expected integer but found %s", $FILE, $LINE, $COL, lua_typename(L, ttnov($EXP)));
+                $THROWINTEGER
             }
         ]], {
             EXP = exp,
             VAR = cvar,
             FILE = c_string_literal(loc.filename),
             LINE = c_integer_literal(loc.line),
             COL = c_integer_literal(loc.col),
+            THROWFLOAT = codethrow(ctx, "%s:%d:%d: type error, number '%f' has no integer representation", { "$FILE", "$LINE", "$COL", "_v" }),
+            THROWINTEGER = codethrow(ctx, "%s:%d:%d: type error, expected integer but found %s", { "$FILE", "$LINE", "$COL", "lua_typename(L, ttnov($EXP))" })
         })
     elseif typ._tag == "Type.Float" then
         return render([[
@@ -193,14 +204,15 @@ local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:s
             } else if (ttisinteger($EXP)) {
                 $VAR = (lua_Number)ivalue($EXP);
             } else {
-                luaL_error(L, "%s:%d:%d: type error, expected float but found %s", $FILE, $LINE, $COL, lua_typename(L, ttnov($EXP)));
+                $THROW
             }
         ]], {
             EXP = exp,
             VAR = cvar,
             FILE = c_string_literal(loc.filename),
             LINE = c_integer_literal(loc.line),
             COL = c_integer_literal(loc.col),
+            THROW = codethrow(ctx, "%s:%d:%d: type error, expected float but found %s", { "$FILE", "$LINE", "$COL", "lua_typename(L, ttnov($EXP))" })
         })
     elseif typ._tag == "Type.Boolean" then
         return render([[
@@ -247,13 +259,13 @@ local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:s
                 lua_pushlightuserdata(L, _tag);
                 if(lua_rawget(L, LUA_REGISTRYINDEX) == LUA_TNIL) {
                     setuvalue(L, L->top, _ud);
-                    luaL_error(L, "%s:%d:%d: type error, expected %s but found %s", $FILE, $LINE, $COL, "$NAME", luaL_tolstring(L, -1, NULL));
+                    $THROWNIL
                 } else {
-                    luaL_error(L, "%s:%d:%d: type error, expected %s but found %s", $FILE, $LINE, $COL, "$NAME", lua_tostring(L, -1));
+                    $THROWUD
                 }
               }
             } else {
-              luaL_error(L, "%s:%d:%d: type error, expected %s but found %s", $FILE, $LINE, $COL, "$NAME", lua_typename(L, ttnov($EXP)));
+              $THROWPRIM
             }
         ]], {
             TAG = type2tagname(ctx, typ),
@@ -262,7 +274,10 @@ local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:s
             COL = c_integer_literal(loc.col),
             EXP = exp,
             VAR = cvar,
-            NAME = types.tostring(typ)
+            NAME = types.tostring(typ),
+            THROWNIL = codethrow(ctx, "%s:%d:%d: type error, expected %s but found %s", { "$FILE", "$LINE", "$COL", '"$NAME"', "luaL_tolstring(L, -1, NULL)" }),
+            THROWUD = codethrow(ctx, "%s:%d:%d: type error, expected %s but found %s", { "$FILE", "$LINE", "$COL", '"$NAME"', "lua_tostring(L, -1)" }),
+            THROWPRIM = codethrow(ctx, "%s:%d:%d: type error, expected %s but found %s", { "$FILE", "$LINE", "$COL", '"$NAME"', "lua_typename(L, ttnov($EXP))" })
         })
     else
         error("invalid type " .. types.tostring(typ))
@@ -271,7 +286,7 @@ local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:s
         if (TITAN_LIKELY($PREDICATE($EXP))) {
             $GETSLOT;
         } else {
-            luaL_error(L, "%s:%d:%d: type error, expected %s but found %s", $FILE, $LINE, $COL, $TAG, lua_typename(L, ttnov($EXP)));
+            $THROW
         }
     ]], {
         EXP = exp,
@@ -281,7 +296,8 @@ local function checkandget(ctx, typ --[[:table]], cvar --[[:string]], exp --[[:s
         FILE = c_string_literal(loc.filename),
         LINE = c_integer_literal(loc.line),
         COL = c_integer_literal(loc.col),
-})
+        THROW = codethrow(ctx, "%s:%d:%d: type error, expected %s but found %s", { "$FILE", "$LINE", "$COL", "$TAG", "lua_typename(L, ttnov($EXP))" })
+    })
 end
 
 function checkandset(ctx, typ --[[:table]], dst --[[:string]], src --[[:string]], loc --[[:table]])
@@ -294,6 +310,7 @@ function checkandset(ctx, typ --[[:table]], dst --[[:string]], src --[[:string]]
             } else if (ttisinteger($SRC)) {
                 setfltvalue($DST, ((lua_Number)ivalue($SRC)));
             } else {
+                $THROW
                 luaL_error(L, "%s:%d:%d: type error, expected float but found %s", $FILE, $LINE, $COL, lua_typename(L, ttnov($SRC)));
             }
         ]], {
@@ -302,6 +319,7 @@ function checkandset(ctx, typ --[[:table]], dst --[[:string]], src --[[:string]]
             FILE = c_string_literal(loc.filename),
             LINE = c_integer_literal(loc.line),
             COL = c_integer_literal(loc.col),
+            THROW = codethrow(ctx, "%s:%d:%d: type error, expected float but found %s", { "$FILE", "$LINE", "$COL", "lua_typename(L, ttnov($SRC))" })
         })
     elseif typ._tag == "Type.Boolean" then tag = "boolean"
     elseif typ._tag == "Type.Nil" then tag = "nil"
@@ -345,7 +363,7 @@ function checkandset(ctx, typ --[[:table]], dst --[[:string]], src --[[:string]]
         if (TITAN_LIKELY($PREDICATE($SRC))) {
             setobj2t(L, $DST, $SRC);
         } else {
-            luaL_error(L, "%s:%d:%d: type error, expected %s but found %s", $FILE, $LINE, $COL, $TAG, lua_typename(L, ttnov($SRC)));
+            $THROW
         }
     ]], {
         TAG = c_string_literal(tag),
@@ -355,7 +373,8 @@ function checkandset(ctx, typ --[[:table]], dst --[[:string]], src --[[:string]]
         FILE = c_string_literal(loc.filename),
         LINE = c_integer_literal(loc.line),
         COL = c_integer_literal(loc.col),
-})
+        THROW = codethrow(ctx, "%s:%d:%d: type error, expected %s but found %s", { "$FILE", "$LINE", "$COL", "$TAG", "lua_typename(L, ttnov($SRC))" })
+    })
 end
 
 local function setslot(typ --[[:table]], dst --[[:string]], src --[[:string]])
@@ -1704,7 +1723,7 @@ local function generate_binop_idiv_int(exp, ctx)
         ${Q_DECL}
         if (l_castS2U(${N}) + 1u <= 1u) {
             if (${N} == 0){
-                luaL_error(L, "error at line %d, divide by zero", $LINE);
+                $THROW_DIV0
             } else {
                 ${Q} = intop(-, 0, ${M});
             }
@@ -1722,6 +1741,7 @@ local function generate_binop_idiv_int(exp, ctx)
         Q = qname,
         Q_DECL = qdecl,
         LINE = c_integer_literal(exp.loc.line),
+        THROW_DIV0 = codethrow(ctx, "error at line %d, divide by zero", { "$LINE" })
     })
     return cstats, qname
 end
@@ -1759,7 +1779,7 @@ local function generate_binop_mod_int(exp, ctx)
         ${R_DECL};
         if (l_castS2U(${N}) + 1u <= 1u) {
             if (${N} == 0){
-                luaL_error(L, "error at line %d, % by zero", $LINE);
+                $THROW_MOD0
             } else {
                 ${R} = 0;
             }
@@ -1777,6 +1797,7 @@ local function generate_binop_mod_int(exp, ctx)
         R = rname,
         R_DECL = rdecl,
         LINE = c_integer_literal(exp.loc.line),
+        THROW_MOD0 = codethrow(ctx, "error at line %d, % by zero", { "$LINE" })
     })
     return cstats, rname
 end
@@ -2169,7 +2190,7 @@ function codeexp(ctx, node, iscondition, target)
             $TMPNAME1 = $CEXP;
             $TMPNAME2 = l_floor($TMPNAME1);
             if ($TMPNAME1 != $TMPNAME2) {
-                luaL_error(L, "type error at line %d, number '%f' has no integer representation", $LINE, $TMPNAME1);
+                $THROW_WRONG_INT
             } else {
                 lua_numbertointeger($TMPNAME2, &$TMPNAME3);
             }
@@ -2182,7 +2203,8 @@ function codeexp(ctx, node, iscondition, target)
             TMPNAME1 = tmpname1,
             TMPNAME2 = tmpname2,
             TMPNAME3 = tmpname3,
-            LINE = c_integer_literal(node.loc.line)
+            LINE = c_integer_literal(node.loc.line),
+            THROW_WRONG_INT = codethrow(ctx, "type error at line %d, number '%f' has no integer representation", { "$LINE", "$TMPNAME1" })
         })
         return cfloor, tmpname3
     elseif tag == "Ast.ExpCast" and node._type._tag == "Type.String" then
@@ -2243,7 +2265,7 @@ function codeexp(ctx, node, iscondition, target)
             $CSTATS
             $CTMP
             if(TITAN_UNLIKELY(ttisnil(&$CEXP))) {
-                luaL_error(L, "%s:%d:%d: type error, expected %s but found nil", $FILE, $LINE, $COL, $TYPENAME);
+                $THROW_WRONG_CAST
             } else {
                 $GETSLOT
             }
@@ -2255,7 +2277,8 @@ function codeexp(ctx, node, iscondition, target)
             LINE = node.loc.line,
             COL = node.loc.col,
             TYPENAME = c_string_literal(types.tostring(node._type)),
-            GETSLOT = getslot(node._type, tmpname, "&" .. cexp)
+            GETSLOT = getslot(node._type, tmpname, "&" .. cexp),
+            THROW_WRONG_CAST = codethrow(ctx, "%s:%d:%d: type error, expected %s but found nil", { "$FILE", "$LINE", "$COL", "$TYPENAME" })
         }), tmpname
     elseif tag == "Ast.ExpCast" and node._type._tag == "Type.Pointer" then
         local cstats, cexp = codeexp(ctx, node.exp)
@@ -2367,6 +2390,13 @@ local function genluaentry(tlcontext, titan_name, titan_entry, typ, loc, lua_nam
         table.insert(stats, ctype(ptype) .. " " .. pname .. " = " .. initval(ptype) .. ";")
     end
     local rettype = typ.rettypes[1]
+    if #params > 0 then
+        table.insert(stats, [[
+            lua_pushvalue(L, 1); /* make space for error slot */
+            lua_pushnil(L);
+            lua_replace(L, 1); /* replace first stack element with nil, this is our error slot */
+        ]])
+    end
     table.insert(stats, render([[
         lua_checkstack(L, $NRET);
         TValue *_firstret = L->top;
@@ -2390,6 +2420,7 @@ local function genluaentry(tlcontext, titan_name, titan_entry, typ, loc, lua_nam
         }))
     end
     table.insert(stats, render([[
+        L->errfunc = __save_errfunc;
         return $NRET;
     ]], {
         NRET = #typ.rettypes
@@ -2400,11 +2431,16 @@ local function genluaentry(tlcontext, titan_name, titan_entry, typ, loc, lua_nam
         if((L->top - func - 1) != $EXPECTED) {
             luaL_error(L, "calling Titan function %s with %d arguments, but expected %d", $NAME, L->top - func - 1, $EXPECTED);
         }
+        $ERRORSLOT
+        int __save_errfunc = L->errfunc;
+        lua_pushcclosure(L, errorhandler, 0);
+        L->errfunc = savestack(L, L->top-1);
         CClosure *_mod = clCvalue(&clCvalue(func)->upvalue[0]);
         $BODY
     }]], {
         LUANAME = lua_name,
         EXPECTED = c_integer_literal(#params),
+        ERRORSLOT = #params == 0 and "lua_pushnil(L);" or "",
         NAME = c_string_literal(titan_name),
         BODY = table.concat(stats, "\n"),
     })
@@ -2567,6 +2603,7 @@ local preamble = [[
 #include "lstring.h"
 #include "lvm.h"
 #include "lobject.h"
+#include "ldo.h"
 
 #include "titan.h"
 

diff --git a/titan-compiler/driver.lua b/titan-compiler/driver.lua
@@ -13,7 +13,7 @@ driver.imported = {}
 
 driver.TITAN_BIN_PATH = os.getenv("TITAN_PATH_0_5") or os.getenv("TITAN_PATH") or ".;/usr/local/lib/titan/0.5"
 driver.TITAN_SOURCE_PATH = "."
-driver.LUA_SOURCE_PATH = "lua-5.3.4/src/"
+driver.LUA_SOURCE_PATH = "lua-5.3.5/src/"
 driver.TITAN_RUNTIME_PATH = "titan-runtime/"
 driver.CFLAGS = "--std=c99 -O2 -Wall -fPIC"
 driver.CC = "cc"
@@ -139,7 +139,9 @@ end
 local function check_runtime()
     local runtime_c = driver.TITAN_RUNTIME_PATH .. "titan.c"
     local runtime_o = driver.TITAN_RUNTIME_PATH .. "titan.o"
-    if not lfs.attributes(runtime_o, "size") then
+    local titanc_mtime = lfs.attributes(runtime_c, "modification")
+    local titano_mtime = lfs.attributes(runtime_o, "modification")
+    if (not titano_mtime) or (titano_mtime < titanc_mtime) then
         local args = {driver.CC, driver.CFLAGS, "-c", runtime_c,
             "-I", driver.TITAN_RUNTIME_PATH, "-I", driver.LUA_SOURCE_PATH,
             "-o", runtime_o }