src/developer/debug/zxdb/symbols/find_line_unittest.cc

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/developer/debug/zxdb/symbols/find_line.h"

#include <gtest/gtest.h>

#include "src/developer/debug/zxdb/symbols/function.h"
#include "src/developer/debug/zxdb/symbols/mock_line_table.h"

namespace zxdb {

TEST(FindLine, GetAllLineTableMatchesInUnit) {
  // The same file name can appear more than once as a line table "file" (they could be duplicates,
  // or they could be encoded with a different directory that still resolves to the same file).
  MockLineTable::FileNameVector files;
  files.push_back("file1.cc");  // Name for file ID #1.
  files.push_back("file2.cc");  // Name for file ID #2.
  files.push_back("file1.cc");  // Name for file ID #3 (duplicate of #1).

  MockLineTable::RowVector rows;
  rows.push_back(MockLineTable::MakeStatementRow(0x1000, 1, 1));  // File #1, line 1.
  rows.push_back(MockLineTable::MakeStatementRow(0x1001, 1, 2));
  rows.push_back(MockLineTable::MakeStatementRow(0x1002, 2, 1));  // File #2, line 1.
  rows.push_back(MockLineTable::MakeStatementRow(0x1003, 1, 1));  // Dupe for File 1, line 1.
  rows.push_back(MockLineTable::MakeStatementRow(0x1004, 1, 90));
  rows.push_back(MockLineTable::MakeStatementRow(0x1005, 1, 100));
  rows.push_back(MockLineTable::MakeStatementRow(0x1006, 3, 95));
  rows.push_back(MockLineTable::MakeStatementRow(0x1007, 3, 100));
  rows.push_back(MockLineTable::MakeStatementRow(0x1008, 1, 98));
  rows.push_back(MockLineTable::MakeEndSequenceRow(0x1009, 1, 98));

  MockLineTable table(files, rows);

  // There are two exact matches for line 1.
  auto out = GetAllLineTableMatchesInUnit(table, "file1.cc", 1);
  ASSERT_EQ(2u, out.size());
  EXPECT_EQ(LineMatch(0x1000, 1, 0), out[0]);
  EXPECT_EQ(LineMatch(0x1003, 1, 0), out[1]);

  // Searching for line 99 should catch both the 90->100 and the 95->100 transitions.
  out = GetAllLineTableMatchesInUnit(table, "file1.cc", 99);
  ASSERT_EQ(2u, out.size());
  EXPECT_EQ(LineMatch(0x1005, 100, 0), out[0]);
  EXPECT_EQ(LineMatch(0x1007, 100, 0), out[1]);

  // Searching for something greater than 100 should fail.
  out = GetAllLineTableMatchesInUnit(table, "file1.cc", 101);
  EXPECT_TRUE(out.empty());
}

// Out-of-order lines. In this case there was some later code moved before the line being searched
// for, even though the transition of addresses goes in the opposite direction (high to low), we
// should find the line.
TEST(FindLine, GetAllLineTableMatchesInUnit_Reverse) {
  MockLineTable::FileNameVector files = {"file1.cc"};

  MockLineTable::RowVector rows;
  rows.push_back(MockLineTable::MakeStatementRow(0x1000, 1, 105));  // Later code moved before.
  rows.push_back(MockLineTable::MakeStatementRow(0x1001, 1, 101));  // Best match.
  rows.push_back(MockLineTable::MakeStatementRow(0x1002, 1, 91));   //
  rows.push_back(MockLineTable::MakeStatementRow(0x1003, 1, 103));  // Less-good match.
  rows.push_back(MockLineTable::MakeEndSequenceRow(0x1004, 1, 103));

  MockLineTable table(files, rows);

  auto out = GetAllLineTableMatchesInUnit(table, "file1.cc", 100);
  ASSERT_EQ(1u, out.size());
  EXPECT_EQ(LineMatch(0x1001, 101, 0), out[0]);
}

TEST(FindLine, GetBestLineMatches) {
  // Empty input.
  auto out = GetBestLineMatches({});
  EXPECT_TRUE(out.empty());

  // Should return the smallest line #.
  out = GetBestLineMatches(
      {LineMatch(0x1000, 10, 0), LineMatch(0x1001, 7, 0), LineMatch(0x1002, 100, 0)});
  ASSERT_EQ(1u, out.size());
  EXPECT_EQ(LineMatch(0x1001, 7, 0), out[0]);

  // When the smallest match has dupes, all should be returned assuming the functions are different.
  out = GetBestLineMatches({LineMatch(0x1000, 10, 0), LineMatch(0x1001, 20, 1),
                            LineMatch(0x1002, 10, 2), LineMatch(0x1003, 30, 3)});
  ASSERT_EQ(2u, out.size());
  EXPECT_EQ(LineMatch(0x1000, 10, 0), out[0]);
  EXPECT_EQ(LineMatch(0x1002, 10, 2), out[1]);

  // Dupes in the same function should return the smallest match.
  out = GetBestLineMatches({LineMatch(0x1002, 10, 0),    // Match, discarded due to higher addr.
                            LineMatch(0x1001, 20, 0),    // No line match.
                            LineMatch(0x1000, 10, 0),    // Match, this one last lowest addr.
                            LineMatch(0x1003, 10, 1)});  // Same line, different function.
  ASSERT_EQ(2u, out.size());
  EXPECT_EQ(LineMatch(0x1000, 10, 0), out[0]);
  EXPECT_EQ(LineMatch(0x1003, 10, 1), out[1]);
}

// Tests looking for a prologue end marker that's not present.
TEST(FindLine, GetFunctionPrologueSize_NotFound) {
  MockLineTable::FileNameVector files = {"file.cc"};

  // This line table matches what's generated by GCC (which doesn't seem to generate prologue_end
  // annotations) for the code:
  //   1  #include <stdio.h>
  //   2
  //   3  void PrologueTest() { int a; scanf("%d", &a); printf("Scanned %d\n", a);
  //   4    printf("END\n");
  //   5  }
  //   6
  //   7  int main(int argc, char **argv) {
  //   8    PrologueTest();
  //   9    return 0;
  //  10  }
  MockLineTable::RowVector rows;
  // clang-format off
  rows.push_back(MockLineTable::MakeStatementRow(  0x1155, 1, 3));  // PrologueTest function start.
  rows.push_back(MockLineTable::MakeStatementRow(  0x115d, 1, 3));  // First code in function.
  rows.push_back(MockLineTable::MakeStatementRow(  0x1175, 1, 3));
  rows.push_back(MockLineTable::MakeStatementRow(  0x118b, 1, 4));
  rows.push_back(MockLineTable::MakeStatementRow(  0x1197, 1, 5));
  rows.push_back(MockLineTable::MakeStatementRow(  0x119a, 1, 7));  // main function start.
  rows.push_back(MockLineTable::MakeStatementRow(  0x11a9, 1, 8));  // First code in function.
  rows.push_back(MockLineTable::MakeStatementRow(  0x11ae, 1, 9));
  rows.push_back(MockLineTable::MakeStatementRow(  0x11b3, 1, 10));
  rows.push_back(MockLineTable::MakeEndSequenceRow(0x11b5, 1, 10));
  // clang-format on

  MockLineTable table(files, rows);

  auto prologue_test_fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  prologue_test_fn->set_code_ranges(AddressRanges(AddressRange(0x1155, 0x119a)));

  auto main_fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  main_fn->set_code_ranges(AddressRanges(AddressRange(0x119a, 0x11b5)));

  // Prologue ends at 2nd line table entry (0x115d for PrologueTest(), 0x11a9 for main()).
  EXPECT_EQ(0x8u, GetFunctionPrologueSize(table, prologue_test_fn.get()));
  EXPECT_EQ(0xfu, GetFunctionPrologueSize(table, main_fn.get()));
}

// Test looking for a prologue end marker that's present.
TEST(FindLine, GetFunctionPrologueSize_Marked) {
  MockLineTable::FileNameVector files = {"file.cc"};

  // This line table is the Clang version of the same code from above. It marks the prologue end.
  // Here, we manually added an additional row that Clang didn't to push the marked prologue end
  // past the 2nd row of a function. Otherwise this case would be identical to the above.
  MockLineTable::RowVector rows;
  // clang-format off
  rows.push_back(MockLineTable::MakeStatementRow(   0x2010d0, 1, 3));  // PrologueTest fn start.
  rows.push_back(MockLineTable::MakeStatementRow(   0x2010d1, 1, 3));  // Added manually.
  rows.push_back(MockLineTable::MakePrologueEndRow( 0x2010d8, 1, 3));  // prologue_end
  rows.push_back(MockLineTable::MakeNonStatementRow(0x2010ed, 1, 3));
  rows.push_back(MockLineTable::MakeNonStatementRow(0x2010f0, 1, 3));
  rows.push_back(MockLineTable::MakeStatementRow(   0x201104, 1, 4));  // Invalid fn decl. here.
  rows.push_back(MockLineTable::MakeStatementRow(   0x201118, 1, 5));
  rows.push_back(MockLineTable::MakeStatementRow(   0x201120, 1, 7));  // main function start.
  rows.push_back(MockLineTable::MakePrologueEndRow( 0x201136, 1, 8));  // prologue_end
  rows.push_back(MockLineTable::MakeStatementRow(   0x20113d, 1, 9));
  rows.push_back(MockLineTable::MakeEndSequenceRow( 0x201143, 1, 9));
  // clang-format on

  MockLineTable table(files, rows);

  auto prologue_test_fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  prologue_test_fn->set_code_ranges(AddressRanges(AddressRange(0x2010d0, 0x20111e)));

  auto main_fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  main_fn->set_code_ranges(AddressRanges(AddressRange(0x201120, 0x201143)));

  // Prologue ends at 2nd line table entry (0x115d for PrologueTest(), 0x11a9 for main()).
  EXPECT_EQ(0x8u, GetFunctionPrologueSize(table, prologue_test_fn.get()));
  EXPECT_EQ(0x16u, GetFunctionPrologueSize(table, main_fn.get()));

  // Make a function declaration that consists of exactly one line. This is invalid and not
  // actually in the example code. The prologue computation code should not try to go outside of
  // this function to get the prologue, so it will return 0.
  auto invalid_fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  invalid_fn->set_code_ranges(AddressRanges(AddressRange(0x201104, 0x201118)));
  EXPECT_EQ(0u, GetFunctionPrologueSize(table, invalid_fn.get()));

  // Make a function that's before the table
  auto floating_fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  floating_fn->set_code_ranges(AddressRanges(AddressRange(0x10000, 0x10010)));
  EXPECT_EQ(0u, GetFunctionPrologueSize(table, floating_fn.get()));

  // One that's after the table.
  floating_fn->set_code_ranges(AddressRanges(AddressRange(0x300000, 0x300020)));
  EXPECT_EQ(0u, GetFunctionPrologueSize(table, floating_fn.get()));
}

// A synthetic test for when the prologue end is immediately followed by compiler-synthesized code
// (marked as "line 0") that the user doesn't want to see.
TEST(FindLine, GetFunctionPrologueSize_ZeroRows) {
  MockLineTable::FileNameVector files = {"file.cc"};

  // This line table is the Clang version of the same code from above. It marks the prologue end.
  MockLineTable::RowVector rows;
  // clang-format off
  rows.push_back(MockLineTable::MakeStatementRow(  0x1155, 1, 3));  // PrologueTest function start.
  rows.push_back(MockLineTable::MakeStatementRow(  0x115d, 1, 0));  // Generated code
  rows.push_back(MockLineTable::MakeStatementRow(  0x1175, 1, 3));  // Identified first addr.
  rows.push_back(MockLineTable::MakeStatementRow(  0x118b, 1, 4));
  rows.push_back(MockLineTable::MakeStatementRow(  0x1197, 1, 5));
  rows.push_back(MockLineTable::MakeEndSequenceRow(0x119a, 1, 5));
  // clang-format on

  MockLineTable table(files, rows);

  auto fn = fxl::MakeRefCounted<Function>(DwarfTag::kSubprogram);
  fn->set_code_ranges(AddressRanges(AddressRange(0x1155, 0x119a)));

  // Test with no explicltly marked prologue_end.
  EXPECT_EQ(0x20u, GetFunctionPrologueSize(table, fn.get()));

  // Explicitly mark the prologue end and try again.
  rows[1].PrologueEnd = 1;
  EXPECT_EQ(0x20u, GetFunctionPrologueSize(table, fn.get()));
}

}  // namespace zxdb