From a9efb98285713dac64a35e9eb166119d33d5fdc2 Mon Sep 17 00:00:00 2001
From: Walter Bright <walter@walterbright.com>
Date: Wed, 9 Jun 2021 23:59:31 -0700
Subject: [PATCH] ImportC add simple array initialization

---
 src/dmd/initsem.d       | 41 ++++++++++++++++++++++++++++++++++++++---
 src/dmd/todt.d          | 16 +++++++++++++++-
 test/runnable/cstuff2.c | 22 ++++++++++++++++++++++
 3 files changed, 75 insertions(+), 4 deletions(-)
 create mode 100644 test/runnable/cstuff2.c

diff --git a/src/dmd/initsem.d b/src/dmd/initsem.d
index 234f155882d3..926b0782a20b 100644
--- a/src/dmd/initsem.d
+++ b/src/dmd/initsem.d
@@ -559,11 +559,46 @@ extern(C++) Initializer initializerSemantic(Initializer init, Scope* sc, ref Typ
         return i;
     }
 
-    Initializer visitC(CInitializer i)
+    Initializer visitC(CInitializer ci)
     {
         //printf("CInitializer::semantic()\n");
-        error(i.loc, "C initializers not supported yet");
-        return err();
+        t = t.toBasetype();
+        auto tsa = t.isTypeSArray();
+        if (!tsa)
+        {
+            error(ci.loc, "C non-static-array initializers not supported yet");
+            return err();
+        }
+
+        const uint amax = 0x8000_0000;
+        bool errors;
+        auto tn = tsa.nextOf();
+        auto dil = ci.initializerList[];
+        foreach (di; dil)
+        {
+            if (di.designatorList)
+            {
+                error(ci.loc, "C designator-list not supported yet");
+                return err();
+            }
+            di.initializer = di.initializer.initializerSemantic(sc, tn, needInterpret);
+            if (di.initializer.isErrorInitializer())
+                errors = true;
+        }
+
+        if (errors)
+            return err();
+
+        const sz = tn.size();
+        bool overflow;
+        const max = mulu(dil.length, sz, overflow);
+        if (overflow || max >= amax)
+        {
+            error(ci.loc, "array dimension %llu exceeds max of %llu", ulong(dil.length), ulong(amax / sz));
+            return err();
+        }
+
+        return ci;
     }
 
     final switch (init.kind)
diff --git a/src/dmd/todt.d b/src/dmd/todt.d
index e3587b8c5499..c45046d52088 100644
--- a/src/dmd/todt.d
+++ b/src/dmd/todt.d
@@ -79,6 +79,9 @@ extern (C++) void Initializer_toDt(Initializer init, ref DtBuilder dtb)
 
     void visitStruct(StructInitializer si)
     {
+        /* The StructInitializer was converted to a StructLiteralExp,
+         * which is converted to dtb by membersToDt()
+         */
         //printf("StructInitializer.toDt('%s')\n", si.toChars());
         assert(0);
     }
@@ -197,6 +200,17 @@ extern (C++) void Initializer_toDt(Initializer init, ref DtBuilder dtb)
         Expression_toDt(ei.exp, dtb);
     }
 
+    void visitC(CInitializer ci)
+    {
+        //printf("CInitializer::semantic()\n");
+        auto dil = ci.initializerList[];
+        foreach (di; dil)
+        {
+            assert(!di.designatorList);
+            Initializer_toDt(di.initializer, dtb);
+        }
+    }
+
     final switch (init.kind)
     {
         case InitKind.void_:   return visitVoid  (cast(  VoidInitializer)init);
@@ -204,7 +218,7 @@ extern (C++) void Initializer_toDt(Initializer init, ref DtBuilder dtb)
         case InitKind.struct_: return visitStruct(cast(StructInitializer)init);
         case InitKind.array:   return visitArray (cast( ArrayInitializer)init);
         case InitKind.exp:     return visitExp   (cast(   ExpInitializer)init);
-        case InitKind.C_:      assert(0);
+        case InitKind.C_:      return visitC     (cast(     CInitializer)init);
     }
 }
 
diff --git a/test/runnable/cstuff2.c b/test/runnable/cstuff2.c
new file mode 100644
index 000000000000..79a81ccf70b3
--- /dev/null
+++ b/test/runnable/cstuff2.c
@@ -0,0 +1,22 @@
+
+int printf(const char *, ...);
+void exit(int);
+
+void test1()
+{
+    static int a[3] = {1, 2, 3};
+    if (a[0] != 1 ||
+        a[1] != 2 ||
+        a[2] != 3)
+    {
+        printf("error 1\n");
+        exit(1);
+    }
+}
+
+int main()
+{
+    test1();
+    return 0;
+}
+