tccrun: win64: add unwind function table for dynamic code

This works only when tcc.exe is compiled using MSC.  MinGW does
something in the startup code that defeats it.

1 files changed, 49 insertions, 38 deletions

diff --git a/tccpe.c b/tccpe.c
index 22b61a6..3510d9c 100644
--- a/tccpe.c
+++ b/tccpe.c
@@ -1694,54 +1694,65 @@ ST_FUNC int pe_add_dll(struct TCCState *s, const char *libname)
 
 /* ------------------------------------------------------------- */
 #ifdef TCC_TARGET_X86_64
-ST_FUNC void pe_add_unwind_data(unsigned start, unsigned end, unsigned stack)
+static unsigned pe_add_uwwind_info(TCCState *s1)
 {
-    static const char uw_info[] = {
-        0x01, // UBYTE: 3 Version , UBYTE: 5 Flags
-        0x04, // UBYTE Size of prolog
-        0x02, // UBYTE Count of unwind codes
-        0x05, // UBYTE: 4 Frame Register (rbp), UBYTE: 4 Frame Register offset (scaled)
-        // USHORT * n Unwind codes array
-        // 0x0b, 0x01, 0xff, 0xff, // stack size
-        0x04, 0x03, // set frame ptr (mov rsp -> rbp)
-        0x01, 0x50  // push reg (rbp)
-    };
+    if (NULL == s1->uw_pdata) {
+        s1->uw_pdata = find_section(tcc_state, ".pdata");
+        s1->uw_pdata->sh_addralign = 4;
+        s1->uw_sym = put_elf_sym(symtab_section, 0, 0, 0, 0, text_section->sh_num, NULL);
+    }
 
-    struct pe_uw *pe_uw = &tcc_state->pe_unwind;
+    if (0 == s1->uw_offs) {
+        /* As our functions all have the same stackframe, we use one entry for all */
+        static const unsigned char uw_info[] = {
+            0x01, // UBYTE: 3 Version , UBYTE: 5 Flags
+            0x04, // UBYTE Size of prolog
+            0x02, // UBYTE Count of unwind codes
+            0x05, // UBYTE: 4 Frame Register (rbp), UBYTE: 4 Frame Register offset (scaled)
+            // USHORT * n Unwind codes array
+            // 0x0b, 0x01, 0xff, 0xff, // stack size
+            0x04, 0x03, // set frame ptr (mov rsp -> rbp)
+            0x01, 0x50  // push reg (rbp)
+        };
 
-    Section *uw, *pd;
-    WORD *p1;
-    DWORD *p2;
-    unsigned o2;
+        Section *s = text_section;
+        unsigned char *p;
 
-    uw = data_section;
-    pd = pe_uw->pdata;
-    if (NULL == pd)
-    {
-        pe_uw->pdata = pd = find_section(tcc_state, ".pdata");
-        pe_uw->pdata->sh_addralign = 4;
-        section_ptr_add(uw, -uw->data_offset & 3);
-        pe_uw->offs_1 = uw->data_offset;
-        p1 = section_ptr_add(uw, sizeof uw_info);
-        /* use one common entry for all functions */
-        memcpy(p1, uw_info, sizeof uw_info);
-        pe_uw->sym_1 = put_elf_sym(symtab_section, 0, 0, 0, 0, text_section->sh_num, NULL);
-        pe_uw->sym_2 = put_elf_sym(symtab_section, 0, 0, 0, 0, uw->sh_num, NULL);
+        section_ptr_add(s, -s->data_offset & 3); /* align */
+        s1->uw_offs = s->data_offset;
+        p = section_ptr_add(s, sizeof uw_info);
+        memcpy(p, uw_info, sizeof uw_info);
     }
 
-    o2 = pd->data_offset;
-    p2 = section_ptr_add(pd, 3 * sizeof (DWORD));
+    return s1->uw_offs;
+}
+
+ST_FUNC void pe_add_unwind_data(unsigned start, unsigned end, unsigned stack)
+{
+    TCCState *s1 = tcc_state;
+    Section *pd;
+    unsigned o, n, d;
+    struct /* _RUNTIME_FUNCTION */ {
+      DWORD BeginAddress;
+      DWORD EndAddress;
+      DWORD UnwindData;
+    } *p;
+
+    d = pe_add_uwwind_info(s1);
+    pd = s1->uw_pdata;
+    o = pd->data_offset;
+    p = section_ptr_add(pd, sizeof *p);
+
     /* record this function */
-    p2[0] = start;
-    p2[1] = end;
-    p2[2] = pe_uw->offs_1;
+    p->BeginAddress = start;
+    p->EndAddress = end;
+    p->UnwindData = d;
+
     /* put relocations on it */
-    put_elf_reloc(symtab_section, pd, o2,   R_X86_64_RELATIVE, pe_uw->sym_1);
-    put_elf_reloc(symtab_section, pd, o2+4, R_X86_64_RELATIVE, pe_uw->sym_1);
-    put_elf_reloc(symtab_section, pd, o2+8, R_X86_64_RELATIVE, pe_uw->sym_2);
+    for (n = o + sizeof *p; o < n; o += sizeof p->BeginAddress)
+        put_elf_reloc(symtab_section, pd, o,  R_X86_64_RELATIVE, s1->uw_sym);
 }
 #endif
-
 /* ------------------------------------------------------------- */
 #ifdef TCC_TARGET_X86_64
 #define PE_STDSYM(n,s) n