moved DWARF parser to use str8_deserial-style API, added to the parser

layer functionality for interpreting different types of attributes, added support for location lists, and API to enable parsing tags with abstract origin.
2026-07-22 23:47:49 +00:00 · 2025-03-17 10:40:59 -07:00
parent 57208909f1
commit 13352751ec
12 changed files with 5222 additions and 3248 deletions
@@ -0,0 +1,104 @@
+// Copyright (c) 2025 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+internal DW_Input
+dw_input_from_elf_section_table(Arena *arena, String8 raw_image, ELF_BinInfo *bin)
+{
+  Temp scratch = scratch_begin(&arena, 1);
+
+  DW_Input result                              = {0};
+  B32      sect_status[ArrayCount(result.sec)] = {0};
+
+  ELF_Shdr64Array sections = elf_shdr64_array_from_bin(scratch.arena, raw_image, &bin->hdr);
+  String8         sh_names = str8_substr(raw_image, bin->sh_name_range);
+
+  for (U64 sect_idx = 1; sect_idx < sections.count; ++sect_idx) {
+    ELF_Shdr64 *shdr = &sections.v[sect_idx];
+
+    // skip BSS sections
+    if (shdr->sh_type != ELF_SectionCode_ProgBits) {
+      continue;
+    }
+
+    String8     name = {0};
+    str8_deserial_read_cstr(sh_names, shdr->sh_name, &name);
+
+    DW_SectionKind  s      = DW_Section_Null;
+    B32             is_dwo = 0;
+    #define X(_K,_L,_M,_W)                                      \
+      if (str8_match_lit(_L, name, 0)) { s = DW_Section_##_K; } \
+      if (str8_match_lit(_M, name, 0)) { s = DW_Section_##_K; } \
+      if (str8_match_lit(_W, name, 0)) { s = DW_Section_##_K; is_dwo = 1; }
+      DW_SectionKind_XList(X)
+    #undef X
+
+    if (s != DW_Section_Null) {
+      if (sect_status[s]) {
+        Assert(!"too many debug sections with identical name, picking first");
+      } else {
+        Rng1U64 raw_data_range = rng_1u64(shdr->sh_offset, shdr->sh_offset + shdr->sh_size);
+        String8 data           = str8_substr(raw_image, raw_data_range);
+
+        // ELF was compiled with compressed debug info
+        if (shdr->sh_flags & ELF_Shf_Compressed) {
+          String8 comp_data_with_header = data; 
+
+          // read header
+          ELF_Chdr64 chdr64    = {0};
+          U64        chdr_size = 0;
+          if (ELF_HdrIs64Bit(bin->hdr.e_ident)) {
+            chdr_size = str8_deserial_read_struct(comp_data_with_header, 0, &chdr64);
+            if (chdr_size != sizeof(chdr64)) {
+              Assert(!"not enough bytes to read header");
+            }
+          } else if (ELF_HdrIs32Bit(bin->hdr.e_ident)) {
+            ELF_Chdr32 chdr32 = {0};
+            chdr_size = str8_deserial_read_struct(comp_data_with_header, 0, &chdr32);
+            if (chdr_size == sizeof(chdr32)) {
+              chdr64 = elf_chdr64_from_chdr32(chdr32);
+            }
+          }
+
+          AssertAlways(IsPow2(chdr64.ch_addr_align));
+
+          // skip header
+          String8 comp_data = str8_skip(comp_data_with_header, chdr_size);
+
+          // push buffer for the decompressor
+          U8  *decomp_buffer      = push_array_no_zero_aligned(arena, U8, chdr64.ch_size, chdr64.ch_addr_align);
+          U64  actual_decomp_size = 0;
+          
+          // decompress
+          switch (chdr64.ch_type) {
+          case ELF_CompressType_None: {
+            AssertAlways(!"unexpected compression type");
+          } break;
+          case ELF_CompressType_ZLib: {
+            actual_decomp_size = zsinflate(decomp_buffer, chdr64.ch_size, comp_data.str, comp_data.size);
+          } break;
+          case ELF_CompressType_ZStd: {
+            // TODO: zstd lib
+            NotImplemented;
+          } break;
+          default: InvalidPath; break;
+          }
+
+          // TODO: error handling
+          AssertAlways(actual_decomp_size == chdr64.ch_size);
+
+          // set decompressed section data
+          data = str8(decomp_buffer, actual_decomp_size);
+        }
+
+        sect_status[s] = 1;
+        DW_Section *d = &result.sec[s];
+        d->name       = push_str8_copy(arena, name);
+        d->data       = data;
+        d->is_dwo     = is_dwo;
+      }
+    }
+  }
+
+  scratch_end(scratch);
+  return result;
+}