Shrink Loc from 12 to 4 bytes

compiler/src/dmd/cparse.d

@@ -6324,7 +6324,6 @@ final class CParser(AST) : Parser!AST
             while (*p)
                 ++p;
             ++p; // advance to start of next line
-            scanloc.linnum = scanloc.linnum + 1;
         }
 
         if (newSymbols.length)

compiler/src/dmd/dmodule.d

@@ -807,7 +807,7 @@ extern (C++) final class Module : Package
             checkCompiledImport();
             members = p.parseModule();
             assert(!p.md); // C doesn't have module declarations
-            numlines = p.scanloc.linnum;
+            numlines = p.linnum;
         }
         else
         {
@@ -831,7 +831,7 @@ extern (C++) final class Module : Package
             checkCompiledImport();
 
             members = p.parseModuleContent();
-            numlines = p.scanloc.linnum;
+            numlines = p.linnum;
         }
 
         /* The symbol table into which the module is to be inserted.

compiler/src/dmd/dstruct.d

@@ -119,7 +119,7 @@ extern (C++) class StructDeclaration : AggregateDeclaration
     extern (D) this(const ref Loc loc, Identifier id, bool inObject)
     {
         super(loc, id);
-        zeroInit = false; // assume false until we do semantic processing
+        // zeroInit = false; // assume false until we do semantic processing
         ispod = ThreeState.none;
         // For forward references
         type = new TypeStruct(this);

compiler/src/dmd/dsymbolsem.d

@@ -1848,8 +1848,9 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
         buf.writeByte(0);
         const str = buf.extractSlice()[0 .. len];
         const bool doUnittests = global.params.parsingUnittestsRequired();
-        auto loc = adjustLocForMixin(str, cd.loc, global.params.mixinOut);
-        scope p = new Parser!ASTCodegen(loc, sc._module, str, false, global.errorSink, &global.compileEnv, doUnittests);
+        scope p = new Parser!ASTCodegen(sc._module, str, false, global.errorSink, &global.compileEnv, doUnittests);
+        adjustLocForMixin(str, cd.loc, *p.baseLoc, global.params.mixinOut);
+        p.linnum = p.baseLoc.startLine;
         p.nextToken();
 
         auto d = p.parseDeclDefs(0);
@@ -5920,34 +5921,40 @@ private CallExp doAtomicOp (string op, Identifier var, Expression arg)
  * Set up loc for a parse of a mixin. Append the input text to the mixin.
  * Params:
  *      input = mixin text
- *      loc = location to adjust
+ *      loc = location of expansion
+ *      baseLoc = location to adjust
  *      mixinOut = sink for mixin text data
  * Returns:
  *      adjusted loc suitable for Parser
  */
 
-Loc adjustLocForMixin(const(char)[] input, ref const Loc loc, ref Output mixinOut)
+void adjustLocForMixin(const(char)[] input, Loc loc, ref BaseLoc baseLoc, ref Output mixinOut)
 {
-    Loc result;
     if (mixinOut.doOutput)
     {
         const lines = mixinOut.bufferLines;
         writeMixin(input, loc, mixinOut.bufferLines, *mixinOut.buffer);
-        result = Loc(mixinOut.name.ptr, lines + 2, loc.charnum);
+        baseLoc.startLine = lines + 2;
+        baseLoc.filename = mixinOut.name;
+        return;
     }
-    else if (loc.filename)
+
+    SourceLoc sl = SourceLoc(loc);
+    if (sl.filename.length == 0)
     {
-        /* Create a pseudo-filename for the mixin string, as it may not even exist
-         * in the source file.
-         */
-        auto len = strlen(loc.filename) + 7 + (loc.linnum).sizeof * 3 + 1;
-        char* filename = cast(char*)mem.xmalloc(len);
-        snprintf(filename, len, "%s-mixin-%d", loc.filename, cast(int)loc.linnum);
-        result = Loc(filename, loc.linnum, loc.charnum);
+        // Rare case of compiler-generated mixin exp, e.g. __xtoHash
+        baseLoc.filename = "";
+        return;
     }
-    else
-        result = loc;
-    return result;
+
+    /* Create a pseudo-filename for the mixin string, as it may not even exist
+     * in the source file.
+     */
+    auto len = sl.filename.length + 7 + (sl.linnum).sizeof * 3 + 1;
+    char* filename = cast(char*) mem.xmalloc(len);
+    snprintf(filename, len, "%.*s-mixin-%d", cast(int) sl.filename.length, sl.filename.ptr, cast(int) sl.linnum);
+    baseLoc.startLine = sl.line;
+    baseLoc.filename = filename.toDString;
 }
 
 /**************************************

compiler/src/dmd/expressionsem.d

@@ -7654,8 +7654,9 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
         const len = buf.length;
         const str = buf.extractChars()[0 .. len];
         const bool doUnittests = global.params.parsingUnittestsRequired();
-        auto loc = adjustLocForMixin(str, exp.loc, global.params.mixinOut);
-        scope p = new Parser!ASTCodegen(loc, sc._module, str, false, global.errorSink, &global.compileEnv, doUnittests);
+        scope p = new Parser!ASTCodegen(sc._module, str, false, global.errorSink, &global.compileEnv, doUnittests);
+        adjustLocForMixin(str, exp.loc, *p.baseLoc, global.params.mixinOut);
+        p.linnum = p.baseLoc.startLine;
         p.nextToken();
         //printf("p.loc.linnum = %d\n", p.loc.linnum);
 

compiler/src/dmd/frontend.h

@@ -380,28 +380,23 @@ enum class MessageStyle : uint8_t
 struct Loc final
 {
 private:
-    uint32_t _linnum;
-    uint32_t _charnum;
-    uint32_t fileIndex;
+    uint32_t index;
 public:
     static bool showColumns;
     static MessageStyle messageStyle;
     static void set(bool showColumns, MessageStyle messageStyle);
-    Loc(const char* filename, uint32_t linnum, uint32_t charnum);
     uint32_t charnum() const;
-    uint32_t charnum(uint32_t num);
     uint32_t linnum() const;
-    uint32_t linnum(uint32_t num);
     const char* filename() const;
-    void filename(const char* name);
     const char* toChars(bool showColumns = Loc::showColumns, MessageStyle messageStyle = Loc::messageStyle) const;
     bool equals(const Loc& loc) const;
     Loc() :
-        _linnum(),
-        _charnum(),
-        fileIndex()
+        index(0u)
     {
     }
+    Loc(uint32_t index) :
+        index(index)
+        {}
 };
 
 enum class PASS : uint8_t
@@ -5402,23 +5397,23 @@ struct UnionExp final
 private:
     union _AnonStruct_u
     {
-        char exp[30LLU];
-        char integerexp[40LLU];
-        char errorexp[30LLU];
+        char exp[22LLU];
+        char integerexp[32LLU];
+        char errorexp[22LLU];
         char realexp[48LLU];
         char complexexp[64LLU];
-        char symoffexp[64LLU];
-        char stringexp[51LLU];
-        char arrayliteralexp[48LLU];
-        char assocarrayliteralexp[56LLU];
-        char structliteralexp[72LLU];
-        char compoundliteralexp[40LLU];
-        char nullexp[30LLU];
-        char dotvarexp[49LLU];
-        char addrexp[40LLU];
-        char indexexp[58LLU];
-        char sliceexp[65LLU];
-        char vectorexp[53LLU];
+        char symoffexp[56LLU];
+        char stringexp[43LLU];
+        char arrayliteralexp[40LLU];
+        char assocarrayliteralexp[48LLU];
+        char structliteralexp[64LLU];
+        char compoundliteralexp[32LLU];
+        char nullexp[22LLU];
+        char dotvarexp[41LLU];
+        char addrexp[32LLU];
+        char indexexp[50LLU];
+        char sliceexp[57LLU];
+        char vectorexp[45LLU];
     };
     #pragma pack(pop)
 

compiler/src/dmd/globals.h

@@ -417,9 +417,7 @@ typedef unsigned long long uinteger_t;
 struct Loc
 {
 private:
-    unsigned _linnum;
-    unsigned _charnum;
-    unsigned fileIndex;
+    unsigned int index;
 public:
     static void set(bool showColumns, MessageStyle messageStyle);
 
@@ -428,24 +426,12 @@ struct Loc
 
     Loc()
     {
-        _linnum = 0;
-        _charnum = 0;
-        fileIndex = 0;
-    }
-
-    Loc(const char *filename, unsigned linnum, unsigned charnum)
-    {
-        this->linnum(linnum);
-        this->charnum(charnum);
-        this->filename(filename);
+        index = 0;
     }
 
     uint32_t charnum() const;
-    uint32_t charnum(uint32_t num);
     uint32_t linnum() const;
-    uint32_t linnum(uint32_t num);
     const char *filename() const;
-    void filename(const char *name);
 
     const char *toChars(
         bool showColumns = Loc::showColumns,

compiler/src/dmd/identifier.d

@@ -221,12 +221,13 @@ nothrow:
     extern (D) static Identifier generateIdWithLoc(string prefix, const ref Loc loc, string parent = "")
     {
         // generate `<prefix>_L<line>_C<col>`
+        auto sl = SourceLoc(loc);
         OutBuffer idBuf;
         idBuf.writestring(prefix);
         idBuf.writestring("_L");
-        idBuf.print(loc.linnum);
+        idBuf.print(sl.line);
         idBuf.writestring("_C");
-        idBuf.print(loc.charnum);
+        idBuf.print(sl.column);
 
         /**
          * Make sure the identifiers are unique per filename, i.e., per module/mixin
@@ -244,13 +245,13 @@ nothrow:
          * directly, but that would unnecessary lengthen symbols names. See issue:
          * https://issues.dlang.org/show_bug.cgi?id=23722
          */
-        static struct Key { Loc loc; string prefix; string parent; }
+        static struct Key { uint fileOffset; string prefix; string parent; }
         __gshared uint[Key] counters;
 
         static if (__traits(compiles, counters.update(Key.init, () => 0u, (ref uint a) => 0u)))
         {
             // 2.082+
-            counters.update(Key(loc, prefix, parent),
+            counters.update(Key(loc.fileOffset, prefix, parent),
                 () => 1u,          // insertion
                 (ref uint counter) // update
                 {
@@ -262,7 +263,7 @@ nothrow:
         }
         else
         {
-            const key = Key(loc, prefix, parent);
+            const key = Key(loc.fileOffset, prefix, parent);
             if (auto pCounter = key in counters)
             {
                 idBuf.writestring("_");